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  • 101.
    Basu, Somnath
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Lahiri, Ashok Kumar
    Seetharaman, Seshadri
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Materialens processvetenskap.
    Phosphorus partition between liquid steel and CaO-SiO2-FeOx-P2O5-MgO slag containing 15-25 %FeO2007Ingår i: Metallurgical and materials transactions. B, process metallurgy and materials processing science, ISSN 1073-5615, E-ISSN 1543-1916, Vol. 38, nr 4, s. 623-630Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    CaO-SiO2-FeO2-P2O5-MgO bearing slags are typically used in the basic oxygen steelmaking (BOS) process. The partition ratio of phosphorus between slag and steel is an index of the phosphorus holding capacity of the slag, which determines the phosphorus content achievable in the finished steel. The influence of factors such as FeO content and basicity on the phosphorus partition ratio was investigated at two different temperatures. The partition ratio initially increased with basicity but remained constant beyond a basicity of 2.5 to 2.6. An increase in the FeO content up to 18 to 20 mass pct was beneficial for the phosphorus partition at a basicity level of 2 to 3, but a higher concentration of FeO resulted in a decrease in the phosphorus partition ratio; the FeO concentration corresponding to this transition varied with basicity and temperature. At even lower basicities, however, the equilibrium phosphorus partition showed either no change, or a marginally decreasing trend, with an increase in the FeO content.

  • 102.
    Basu, Somnath
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Lahiri, Ashok Kumar
    KTH.
    Seetharaman, Seshadri
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Materialens processvetenskap.
    Phosphorus partition between liquid steel and CaO-SiO2-P2O5-MgO slag containing low FeO2007Ingår i: Metallurgical and materials transactions. B, process metallurgy and materials processing science, ISSN 1073-5615, E-ISSN 1543-1916, Vol. 38, nr 3, s. 357-366Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    CaO-SiO2-FeOx-P2O5-MgO bearing slags are typical in the basic oxygen steelmaking (BOS) process. The partition ratio of phosphorus between slag and steel is an index of the phosphorus holding capacity of the slag, which determines the phosphorus content achievable in the finished steel. The influences of FeO concentration and basicity on the equilibrium phosphorus partition ratios were experimentally determined at temperatures of 1873 and 1923 K, for conditions of MgO saturation. The partition ratio initially increased with basicity but attained a constant value beyond basicity of 2.5. An increase in FeO concentration up to approximately 13 to 14 mass pet was beneficial for phosphorus partition.

  • 103.
    Basu, Somnath
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Lahiri, Ashok Kumar
    KTH.
    Seetharaman, Seshadri
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Materialens processvetenskap.
    Halder, Jayanta
    Change in phosphorus partition during blowing in a commercial BOF2007Ingår i: ISIJ International, ISSN 0915-1559, E-ISSN 1347-5460, Vol. 47, nr 5, s. 766-768Artikel i tidskrift (Refereegranskat)
  • 104.
    Baykov, Vitaly
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Jerlerud Perez, Rosa
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Korzhavyi, Pavel A.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Sundman, Bo
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Termodynamisk modellering.
    Johansson, Börje
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad materialfysik.
    Structural stability of intermetallic phases in the Zr-Sn system2006Ingår i: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 55, nr 5, s. 485-488Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A thermodynamic description of the intermetallic compounds in the Zr-Sn binary system has been obtained using total energy calculations by means of the Vienna ab initio simulation package. Our calculations show that hexagonal compounds Zr5Sn4 and Zr5Sn3 are the most stable phases in the Zr-Sn binary system. Their high stability is found to be due to hybridization of the Sn 5p with Zr 4d electronic states. Based on the calculated energies, the conclusion is made that Zr substitution on the Sri sites takes place in the Zr4Sn phase, which accounts for the unusual stoichiometry of this Cr3Si structure type compound.

  • 105.
    Beaussant Törne, Karin
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Materialfysik, MF.
    Investigation of corrosion properties of metals for degradable implant applications2017Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Nedbrytbara metaller utgör en ny klass av biomaterial med potential attersätta permanenta material i tillfälliga applikationer. Detta för att minskarisken för långvariga biverkningar. I den pågående forskningen för att utvecklanya nedbrytbara metaller är screening av nya material genom in vitro testmetoderett attraktivt alternativ för att undvika onödiga, tidskrävande ochdyrbara djurstudier.Denna avhandling fokuserar på in vitro-testning av zink- och magnesiumbaserademetaller. Inverkan av faktorer såsom sammansättningen av testlösningen,buffersystemet, belastning samt mikrostruktur hos legeringar undersöktes.Genom att använda elektrokemiska in situ tekniker såsom impedansspektroskopi(EIS) är det möjligt att studera gränssnittet mellan metall ochlösning och karakterisera egenskaperna hos den korroderande ytan. Ex situytkaraktäriseringstekniker som svepelektronmikroskopi och infraröd spektroskopianvändes sedan för att komplettera resultaten av de elektrokemiskamätningarna.Korrosionen av zink i Ringer’s lösning fanns vara närmare in vivo korrosionän korrosionen i fosfatbuffrad saltlösning (PBS). Ringers lösning är därför denföredragna testmiljön för långsiktig utvärdering av zinkbaserade metallerDet biologiska buffersystemet (CO2/H2CO3) bör företrädesvis användasför att stabilisera pH-värdet på testlösningen vid magnesiumnedbrytning. NärHEPES användes för att stabilisera pH ökade korrosionshastigheten på grundav bildning av mindre skyddande skikt av korrosionsproduktMöjligheten att använda helblod och plasma som mer kliniskt relevantatestmiljöer utvärderades och befanns producera reproducerbara resultat.Bildning av ett korrosionsskikt bestående av både organiskt och oorganisktmaterial detekterades på zink i både plasma och helblod.När zink prover i helbod utsattes för belastning förhindrade korrosionsskiktetbildningen av mikrosprickor och förtidigt brott av provet. Det varvidare möjligt att detektera tidig sprickbildning på grund av belastning avMagnesium AZ61-legering med EIS.Adsorption av organiska species på zinkytan under anodisk polariseringökar yttäckningen av Zn-joner i helblod. Den ökade yttäckningen leder sedantill utfällningen av ett skyddande skikt av zinkfosfater och en minskadkorrosionshastighet vid högre potentialer.Korrosion av Zn-Mg och Zn-Ag legeringar i Ringers lösning befanns skevia selektiv upplösning. Lokal utfällning av korrosionsprodukter och bildningav ett poröst, mindre skyddande skikt av korrosionsprodukter hittades påZn-Mg legeringar. Den selektiva upplösningen av Zn-Ag legering orsakade enanrikning av AgZn3 vilket kan påverka biokompatibiliteten av ett implantatmed tiden.

  • 106.
    Beheshti, Reza
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap. Nothern Research Institute Narvik, Norway.
    Moosberg-Bustnes, J.
    Kennedy, M. W.
    Aune, R. E.
    Reduction of commercial hematite pellet in isothermal fixed bed-experiments and numerical modelling2016Ingår i: Ironmaking & steelmaking, ISSN 0301-9233, E-ISSN 1743-2812, Vol. 43, nr 1, s. 31-38Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In the present work, fixed bed reduction experiments were conducted at 1173 K over a range of H-2/CO ratios from 0.8 to 2.0 and subsequently modelled numerically (R). The model consists of two one-dimensional, isothermal and time dependent models. The gas-solid reactions were kinetically modelled using a modified shrinking core approach, and the equations were solved using the commercial software COMSOL Multiphysics H. The simulation results agree with thermal gravity experimental data with an average difference of 2.5%. A sensitivity analysis was conducted using the numerical model to establish the optimum operational conditions. The effects of the reducing gas ratio and flow rate, pellet radius and porosity, and the total bed height on the overall degree of reduction were also investigated.

  • 107.
    Beheshti, Reza
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap. Northern Research Institute Narvik, Norway.
    Moosberg-Bustnes, John
    Kennedy, Mark W.
    Aune, Ragnhild E.
    Reduction kinetics of commercial haematite pellet in a fixed bed at 1123-1273 K2016Ingår i: Ironmaking & steelmaking, ISSN 0301-9233, E-ISSN 1743-2812, Vol. 43, nr 5, s. 394-402Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In the present study a model for future use in the modelling of moving bed direct reduction reactors has been developed. The model of a fixed bed reactor for the production of sponge iron from haematite incorporates both heat-and mass-transfer, as well as the chemical reduction rate. The model results were compared to the experimental data obtained from a lab scale reactor in the temperature range 1123-1273 K, as well as to the output from a simple model assuming isothermal conditions. The H-2/CO ratio (beta) of the reducing gas was in all cases varied from 0.8 to 2.0. Overall the non-isothermal model developed permits a more accurate representation of the experimental data than the isothermal estimates, with a typical discrepancy of only 1.3%.

  • 108.
    Berg, Martin
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    The effect of Al2O3, CaO and SiO2 on the phase relations in vanadium containing slags2015Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Today, the main raw material for vanadium production is vanadium containing steelmaking slags. The yield of the vanadium extraction process is affected by the composition of the slag, which in turn determines the phases present, the fractions of the phases and the distribution of the elements between the phases. The aim of this thesis was to experimentally investigate the effect of Al2O3, CaO and SiO2 on the phase relations in vanadium containing slags at 1673 K.

    Synthetic slags, in which the contents of Al2O3, CaO and SiO2 were varied individually, were equilibrated at 1673 K in a vertical resistance furnace. Closed molybdenum crucibles were used to set the oxygen potential of the individual samples.  The phases present, the phase compositions and the phase fractions of the samples were studied using SEM-EDS and LOM combined with an image analysis software.

    The results indicate that the samples consisted of a mixture of a vanadium and iron rich spinel phase and an iron and silicon rich liquid phase at 1673 K. Practically all the vanadium was concentrated into the spinel phase while no free silica or solid phases into which both calcium and vanadium concentrate to a significant extent were observed. The effect of Al2O3 on the phase compositions and the phase fractions was seen to be limited in the range studied. CaO primarily affected the composition of the liquid phases, while the effect on the phase fractions was small. SiO2 affected both the composition and fraction of the phases. The main effect was a decreased fraction of spinel phase, with an increasing vanadium content in the spinel phase as consequence.

  • 109.
    Berg, Martin
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Lee, Jaewoo
    Hyundai Steel, 1480 Bukbusaneop Ro, Dangjin Si 31719, Chungnam, South Korea..
    Sichen, Du
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Partitioning of Calcium Between Liquid Silver and Liquid Iron2018Ingår i: Metallurgical and materials transactions. B, process metallurgy and materials processing science, ISSN 1073-5615, E-ISSN 1543-1916, Vol. 49, nr 3, s. 949-952Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The partitioning of calcium between liquid silver and liquid iron at 1823 K and 1873 K (1550 degrees C and 1600 degrees C) was studied experimentally using a closed molybdenum container. The calcium potential in the container was controlled by the composition of the alloys in equilibrium. The results agreed well with previous experimental measurements and indicated that the effect of temperature was not very pronounced in the temperature range studied.

  • 110.
    Berg, Martin
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Lee, Jaewoo
    Sichen, Du
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Mikro-modellering. KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi. KTH, Skolan för industriell teknik och management (ITM), Industriell produktion.
    Study on the Equilibrium Between Liquid Iron and Calcium Vapor2017Ingår i: Metallurgical and materials transactions. B, process metallurgy and materials processing science, ISSN 1073-5615, E-ISSN 1543-1916, Vol. 48, nr 3, s. 1715-1720Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The solubility of calcium in liquid iron at 1823 K and 1873 K (1550 A degrees C and 1600 A degrees C) as a function of calcium potential was studied experimentally. The measurements were performed using a closed molybdenum holder in which liquid calcium and liquid iron were held at different temperatures. The results indicate a linear relationship between the activity of calcium, relative to pure liquid calcium, and the mole fraction of dissolved calcium in liquid iron, with a negligible temperature dependency in the ranges studied. The activity coefficient of calcium in liquid iron at infinite dilution, was calculated as 1551.

  • 111.
    Berg, Martin
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Sichen, Du
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Effect of Aluminum on the Solubility of Calcium in Liquid Iron at Low Calcium and Aluminum Contents2020Ingår i: ISIJ International, ISSN 0915-1559, E-ISSN 1347-5460, Vol. 60, nr 1, s. 190-192Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The solubility of calcium in liquid iron as a function of aluminum content and calcium potential, at compositions relevant to production of aluminum killed steels, was studied experimentally at 1 873 K. The measurements were made using a closed molybdenum chamber in which iron-aluminum alloys were held. The calcium potential was fixed using pure liquid calcium held at different temperatures. The calcium contents in the iron varied between 6 and 22 ppm by weight and the aluminum contents varied between 70 and 1 900 ppm by weight. The results indicate that the effect of aluminum on the solubility of calcium in iron is very low in the composition ranges studied.

  • 112.
    Bergseth, Ellen
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Tribologi.
    Sosa, Mario
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Tribologi.
    Andersson, Martin
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Tribologi.
    Olofsson, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Tribologi.
    A note on the pitting life of IQ steel versus 16MnCr5 steel in a back to back gear test rig2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    IQ-steel is isotropic (i.e. equally strong in all directions), cleaner, and with less inclusions than 16MnCr5 regular gear steel (RS). IQ-steel is used in diesel inlets and for bearings but to date has not been used for gears. Previous studies, has shown good potential to increase the bending fatigue life of gears. The method in this study is a mechanical test procedure to determine the pitting load capacity of gear transmission lubricants, but with the focus on comparing the pitting load capacity of the two steel types IQ-steel with RS. Times to failures, photographs of the fatigue damage are presented in the study. Gear teeth from each steel type were analysed using SEM. The results, which are based on six tests in total (three IQ-steel and three RS-steel gear pairs), indicate that the IQ-steel may have at least similar surface capacity as the regular steel.

    Keywords: Pitting life, Gear, IQ-steel

  • 113. Bergström, Yngve
    et al.
    Granbom, Ylva
    A dislocation model for the stress-strain behavior of dual phase steels2008Ingår i: IDDRG 2008 International Conference, 2008Konferensbidrag (Refereegranskat)
    Abstract [en]

    The Bergström dislocation model is used to study the influence of coiling temperature after hot rolling on the mechanical properties of the cold rolled SSAB-grade Docol 800DP. Further, the anisotropy-effect for this type of steel, caused for instance by banding, is investigated. The physical dislocation model is based on the assumption that the work hardening behaviour is controlled by the creation, the immobilisation and the remobilisation of dislocations and it is demonstrated that all these processes are strongly influenced by the amount of hard martensite particles in DP-steels. The true strain to necking is a widely used tool for estimating the stretch formability of DP-steels. A detailed discussion regarding the influence of for instance friction stress, rate of dislocation remobilisation and mean free path of dislocation motion is presented. It is also indicated that the best stretch formability of DP-steel is obtained by minimising the quotient between the rate of work hardening at smaller strains with that at larger strains, close to the strain at necking.

  • 114. Bergström, Yngve
    et al.
    Granbom, Ylva
    Product Development/Materials Research, Borlänge, Sweden.
    Sterkenburg, Dirk
    A dislocation based theory for the deformation hardening behavior of DP-steels: Impact of martensite content and ferrite grain size2010Ingår i: Journal of Metallurgy, ISSN 1687-9465, E-ISSN 1687-9473, Vol. 2010, nr 647198Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A dislocation model, accurately describing the uniaxial plastic stress-strain behavior of dual phase (DP) steels, is proposed and the impact of martensite content and ferrite grain size in four commercially produced DP-steels is analyzed. It is assumed that the plastic deformation process is localized to the ferrite. This is taken into account by introducing a non-homogeneity parameter, f(ε), that specifies the volume fraction of ferrite taking active part in the plastic deformation process. It is found that the larger the martensite content the smaller the initial volume fraction of active ferrite which yields a higher initial deformation hardening rate. This explains the high energy absorbing capacity of DP-steels with high volume fractions of martensite. Further, the effect of ferrite grain size strengthening in DP-steels is important. The flow stress grain size sensitivity for DP-steels is observed to be 7 times larger than that for single phase ferrite.

  • 115.
    Beskow, Kristina
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Mikro-modellering.
    Sano, N
    Sichen, Du
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Mikro-modellering.
    Thermodynamic analysis on the formation and chemical development of non-metallic inclusions in ladle treatment of tool steels2006Ingår i: Iron & Steel Technology, ISSN 1547-0423, Vol. 2, s. 103-116Artikel i tidskrift (Refereegranskat)
  • 116.
    Beskow, Kristina
    et al.
    KTH, Tidigare Institutioner, Materialvetenskap.
    Sichen, Du
    KTH, Tidigare Institutioner, Materialvetenskap.
    Ladle glaze: major source of oxide inclusions during ladle treatment of steel2004Ingår i: Ironmaking & steelmaking, ISSN 0301-9233, E-ISSN 1743-2812, Vol. 31, nr 5, s. 393-400Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Samples of ladle lining covered by glaze were taken from industrial ladles of different ages at Uddeholm Tooling AB, Hagfors, Sweden. It was found in the samples taken at and below the slag line that a slag infiltrated layer was covered by an outer layer containing many MgO 'islands' of various sizes. The microstructure of the infiltrating slag was the same as the matrix of the outer layer. The slag was found to decompose into the compound 3CaO. Al2O3 and a liquid phase during the cooling process. The former phase along with tiny MgO particles from the ladle glaze was found to be one of the major sources of inclusions during the degassing and flotation periods of ladle treatment. Thermodynamic analysis indicated that the reaction between the ladle glaze and the slag from the electric arc furnace resulted in the formation of MgO-Al2O3 spinel and an oxide solution, which were also the main inclusions found at the initial stages of ladle treatment. Evidence of this reaction was found in the lining samples taken above the slag line.

  • 117.
    Beskow, Kristina
    et al.
    KTH, Tidigare Institutioner, Materialvetenskap.
    Tripathi, Nagendra N.
    KTH, Tidigare Institutioner, Materialvetenskap.
    Nzotta, M.
    Sandberg, A.
    Sichen, Du
    KTH, Tidigare Institutioner, Materialvetenskap.
    Impact of slag-refractory lining reactions on the formation of inclusions in steel2004Ingår i: Ironmaking & steelmaking, ISSN 0301-9233, E-ISSN 1743-2812, Vol. 31, nr 6, s. 514-518Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The present study was carried out to investigate the impact of slag-refractory lining reactions on the formation of inclusions during ladle treatment of steel. The experiments were conducted on an industrial scale in the ladle at Uddeholm Tooling AB in Hagfors, Sweden. The inclusion chemistry and population during ladle treatment were studied along with the composition of the ladle glaze, taken from the ladle lining. The inclusions in the steel were classified into four groups according to the Swedish standard SS 111116. SEM/EDS analyses were carried out to identify the phases present in both the inclusions and the ladle glaze. The number of inclusions in the steel before deoxidation was found to increase with the ladle age, i.e. the number of times the ladle had been in use. A similar increase was also found after vacuum degassing and before casting. A great portion of inclusions before casting was found to be supplied by ladle glaze. This observation was further confirmed and explained by thermodynamic analysis. The present results show that ladle glaze is a major source of inclusions in the ladle at Uddeholm Tooling.

  • 118.
    Beskow, Kristina
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Mikro-modellering.
    Viswanathan, N. N.
    Jonsson, Lage
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Sichen, Du
    KTH, Tidigare Institutioner, Materialvetenskap.
    Study of the deoxidation of steel with aluminum wire injection in a gas-stirred ladle2001Ingår i: Metallurgical and materials transactions. B, process metallurgy and materials processing science, ISSN 1073-5615, E-ISSN 1543-1916, Vol. 32, nr 2, s. 319-328Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In the present work, the deoxidation of liquid steel with aluminum wire injection in a gas-stirred ladle was studied by mathematical modeling using a computational fluid dynamics (CFD) approach. This was complemented by an industrial trial study conducted at Uddeholm Tooling AB (Hagfors, Sweden). The results of the industrial trials were found to be in accordance with the results of the model calculation. In order to study the aspect of nucleation of alumina, emphasis was given to the initial period of deoxidation, when aluminum wire was injected into the bath. The concentration distributions of aluminum and oxygen were calculated both by considering and not considering the chemical reaction. Both calculations revealed that the driving force for the nucleation of Al2O3 was very high in the region near the upper surface of the bath and close to the wire injection. The estimated nucleation rate in the vicinity of the aluminum wire injection point was much higher than the recommended value for spontaneously homogeneous nucleation, 10(3) nuclei/(cm(3)/s). The results of the model calculation also showed that the alumina nuclei generated at the vicinity of the wire injection point are transported to other regions by the flow.

  • 119. Beyhaghi, Maryam
    et al.
    Kiani-Rashid, Ali-Reza
    Kashefi, Mehrdad
    Khaki, Jalil Vandati
    Jonsson, Stefan
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Mekanisk metallografi.
    Effect of powder reactivity on fabrication and properties of NiAl/Al2O3 composite coated on cast iron using spark plasma sintering2015Ingår i: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 344, s. 1-8Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Powder mixtures of Ni, NiO and Al are ball milled for 1 and 10 h. X-ray diffractometry and differential thermal analysis show that while ball milling for 1 h produced mechanically activated powder; 10 h ball milling produced NiAl and Al2O3 phases. Dense NiAl/Al2O3 composite coatings are formed on gray cast iron substrate by spark plasma sintering (SPS) technique. The effect of powder reactivity on microstructure, hardness and scratch hardness of NiAl/Al2O3 coatings after SPS is discussed. Results show that in the coating sample made of mechanically activated powder in situ synthesis of NiAl/Al2O3 composite coating is fulfilled and a thicker well-formed diffusion bond layer at the interface between coating and substrate is observed. The diffusion of elements across the bond layers and phase evolution in the bond layers were investigated. No pores or cracks were observed at the interface between coating layer and substrate in any of samples. Higher Vickers hardness and scratch hardness values in coating made of 10 h ball milled powder than in coating fabricated from 1 h ball milled powder are attributed to better dispersion of Al2O3 reinforcement particles in NiAl matrix and nano-crystalline structure of NiAl matrix. Scratched surface of coatings did not reveal any cracking or spallation at coating-substrate interface indicating their good adherence at test conditions.

  • 120.
    Bhatti, Ayjwat A.
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Lättkonstruktioner.
    Barsoum, Zuheir
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Lättkonstruktioner.
    Development of efficient three-dimensional welding simulation approach for residual stress estimation in different welded joints2012Ingår i: Journal of Strain Analysis for Engineering Design, ISSN 0309-3247, E-ISSN 2041-3130, Vol. 47, nr 8, s. 539-552Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Based on the available welding simulation approaches found in the literature, an alternative and simplified welding simulation approach is developed, called rapid dumping. It is a sequential thermomechanical approach, which makes use of the moving heat source in thermal analysis and the block-dumping approach in mechanical analysis for prediction of welding residual stresses in three dimensions. It is first developed for longitudinal stiffener joint and then validated by applying on a butt-welded, T-fillet, and multipass tube-flange joints. The temperature-dependent material properties were obtained using JMat Pro software, a java-based material property simulation software. The material properties were validated with experimentally determined material properties found in the literature. The predicted residual stresses were validated by X-ray diffraction measurements on the longitudinal stiffener fillet-welded joint. Using the rapid-dumping approach, the residual stresses obtained at the weld toe were in qualitatively good agreement with the measured residual stresses. The rapid-dumping approach showed to capture the effects of moving heat source and weld start/stop location. In addition, it has reduced the computational time significantly with a preserved accuracy of the estimated welding residual stresses.

  • 121. Bhatti, Ayjwat Awais
    et al.
    Li, Peigang
    Barsoum, Zuheir
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Lättkonstruktioner.
    Svensson, Lars Erik
    Samuelsson, Jack
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Lättkonstruktioner.
    Classification and crackgrowth modeling of cold lap defects in tandem GMAW welding2011Ingår i: International Symposium onFatigue Design & Material Defects, 2011Konferensbidrag (Refereegranskat)
  • 122.
    Bhogireddy, Venkata Sai Pavan Kumar
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Phase Field modeling of sigma phase transformation in duplex stainless steels: Using FiPy-Finite Volume PDE solver2013Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Duplex Stainless Steels (DSS) are used extensively in various industrial applications where the properties of both austenite and ferrite steels are required. Higher mechanical strength and superior corrosion resistance are the advantages of DSS. One of the main drawbacks for Duplex steels is precipitation of sigma phase and other intermetallic phases adversely affecting the mechanical strength and the corrosion behavior of the steels. The precipitation of these secondary phases and the associated brittleness can be due to improper heat treatment. The instability in the microstructure of Duplex stainless steels can be studied by understanding the phase transformations especially the ones involving sigma phase. To reduce the time and effort to be put in for experimental work, computational simulations are used to get an initial understanding on the phase transformations.

    The present thesis work is on the phase transformations involving sigma phase for Fe-Cr system and Fe-Cr-Ni system using theoretical approach in 1D and 2D geometries. A phase field model is implemented for the microstructural evolution in DSS in combination with thermodynamic data collected from the Thermo-Calc software. The Wheeler Boettinger McFadden (WBM) model is used for Gibbs energy interpolation of the system.

    FiPy- Finite volume PDE solver written in python is used to simulate the phase transformation conditions first in Fe-Cr system for ferrite-austenite and ferrite-sigma phase transformations. It is then repeated for Fe-Cr-Ni ternary system. In the present study a model was developed for deriving Gibbs energy expression for sigma phase based on the common tangent condition. This model can be used to describe composition constrained phases and stoichiometric phases using the WBM model in phase field modeling. Cogswell’s theory of using phase order variable instead of an interpolating polynomial in the expression for Gibbs energy of whole system is also tried.

  • 123.
    Bi, Yanyan
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Three Dimensional Determinations of Inclusions in Ferroalloys and Steel Samples2014Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    As the requirements on material properties increase, there has been a demand on an additional knowledge on the effect of impurities in the ferroalloyson the steel cleanness. Thus, the number, morphology, size and composition of inclusions in sixdifferent ferroalloys (FeTi, FeNb, FeSi,SiMn, LC and HC FeCr) were investigatedin this study. This was done in three dimensions (3D) by using a SEM in combination with EDS after electrolytic extraction of the ferroalloy samples. Theresults show that thenon-metallic and metallic inclusions can besuccessfully analyzed on the surface of a film filterafter a separation of the inclusions from the matrix. Overall, the inclusions canbe divided into two categories depending on the melting point. Furthermore, the possible transformation of different kinds of inclusions after their addition to the liquid steel canalso be determined.

    The inclusions and clusters in steel samples of two similar steel grades of high-silicon non-calcium treated (HSiNC) stainless steels were also investigated and compared during ladle treatment and continuous casting. Samples of liquid steel and slag were taken at different stages of the ladle treatment and casting during two plant trials: a low Al steel (LAl) and a high Al steel (HAl). Spherical (SP), irregular and regular (IR) inclusions and clusters (CL) were observed in the samples from both heats. It wasfound that the morphology and composition of inclusions and clusters in both heats were significantly changed during the ladle treatment and casting. Most of inclusions (44-98%) in a low Al steel are MgO-CaO-SiO2-Al2O3spherical inclusions. The compositions of irregular and regularinclusions and clusters in steel samples of a high Al steel were mostly MgO·Al2O3spinel, but also complex sphericalinclusions containing Al2O3-MgO-CaO-SiO2. In addition, the phase stabilitydiagram based on Darken’s quadratic formalism and Redlich-Kister type polynomial was estimated for both heats at a non-infinite solution.

    It is known that clusters in liquid steel have a harmful effect on the casting process and the quality of the final steel product. Therefore, clusters of rare earth metals (REM) were investigated in steel samples of a S30185 stainless steel grade from a pilot trial (PT, 250 kg) and from an industrial heat (IH, 100 t). Samples were taken from the liquid steel at differentholding times after the addition of a mischmetal. The morphology, composition, number and size of clusters in PT and IH steel samples were analyzed and compared as a function of the holding time. It was found that typical clusters with regular and irregular inclusions were the main type of clusters (69%-98%) in all PT and IH steel samples. The composition of inclusions in clusters corresponded mostly to REM-oxides. The size of clusters that were observed in different samples varied mainly from 2 to 23 μm. In addition, the size and number of most clusters in PT are larger than those in IH samples.

    Largesize inclusions are recognized to be crucially harmful for the mechanical properties of steel products. Therefore, predictionsof the maximum size of Al2O3-CaO spherical inclusions in an Fe-10 mass% Ni alloy have been examined based on two dimensional (2D) and three dimensional (3D) investigations. The effects of the number of measurements and unit volume on the estimated 3D results were also investigated.

  • 124.
    Bi, Yanyan
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Karasev, Andrey
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Jönsson, Pär G.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Investigations of inclusions in ferrochromium alloys2014Ingår i: Ironmaking & steelmaking, ISSN 0301-9233, E-ISSN 1743-2812, Vol. 41, nr 10, s. 756-762Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Ferrochromium alloys are commonly added during different stages of steelmaking processes according to the specific steel grade being produced. Depending upon the ferrochromium quality, the addition can also lead to a supply of deleterious inclusions to the liquid steel. Therefore, the number, size, morphology and composition of inclusions in LCFeCr and HCFeCr alloys were investigated. The alloy samples were first treated with electrolytic extraction, followed by filtration to gather the inclusions on a film filter. Thereafter, the characteristics of the inclusions and clusters were investigated in three dimensions by SEM in combination with energy dispersive spectroscopy. The results show that the main inclusion types found in LCFeCr alloys are different to those found in HCFeCr alloys. More specifically, the inclusions in LCFeCr alloys were found to consist of Si-Cr-O and Cr-O oxides as well as intermetallic Cr-Fe inclusions. Moreover, the inclusions in HCFeCr alloys were found to consist of Cr-Mn-S, Cr-C-N, Si-Al-Ca-Mg-O and Ca-O-P inclusions. Overall, the inclusions can be divided into two categories depending on the melting point. Furthermore, the possible transformation of different inclusions after their addition to the liquid steel is discussed.

  • 125.
    Bi, Yanyan
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Karasev, Andrey
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Jönsson, Pär G.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Three Dimensional Evaluations of REM Clusters in Stainless Steel2014Ingår i: ISIJ International, ISSN 0915-1559, E-ISSN 1347-5460, Vol. 54, nr 6, s. 1266-1273Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    It is known that clusters in liquid steel have a harmful effect on the casting process and the quality of the final steel product. In this study, clusters. of rare earth metals (REM) were investigated in steel samples of a S30185 stainless steel grade from a pilot trial (PT, 250 kg) and from an industrial heat (IH, 100 t). Samples were taken from the liquid steel at different holding times after the addition of mischmetal. Thereafter, REM clusters collected on film filters after electrolytic extraction and filtration were investigated in three dimensions (3D) by SEM in combination with EDS. The morphology, composition, number and size of clusters in PT and IH steel samples were analyzed and compared as a function of holding time. It was found that typical clusters with regular and irregular inclusions were the main type of clusters (69%-98%) in all PT and IH steel samples. The composition of inclusions in clusters corresponded mostly to REM-oxides. The size of clusters that were observed in different samples varied mainly from 2 to 23 mu m. In addition, the size and number of most clusters in PT are larger than those in IH samples. Furthermore, the formation mechanisms and evolution of different type of REM clusters were discussed in both PT and IH heats.

  • 126.
    Bi, Yanyan
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Karasev, Andrey
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Jönsson, Pär G.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Three-dimensional investigations of inclusions in ferroalloys2014Ingår i: Steel Research International, ISSN 1611-3683, E-ISSN 1869-344X, Vol. 85, nr 4, s. 659-669Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    As the requirements on material properties increase, there has been a demand on an additional knowledge on the effect of impurities in the ferroalloys on the properties. Thus, the number, morphology, size, and composition of inclusions in four different ferroalloys (FeTi, FeNb, FeSi, and SiMn) were investigated. This was done in three dimensions (3D) by using scanning electron microscopy in combination with energy dispersive spectroscopy after electrolytic extraction of the ferroalloy samples. The non-metallic and metallic inclusions were successfully analyzed on the surface of film filter. Thereafter, the particle size distribution was plotted for most of the non-metallic inclusions. The non-metallic inclusions were found to be REM oxides in FeTi, FeSi, and SiMn, Al2O3, Ti-Nb-S-O oxides in FeNb and silicon oxides in SiMn. Moreover, the intermetallic inclusions were found to be a Ti-Fe phase in FeTi, Ca-Si, and Fe-Si-Ti phases in FeSi and a Mn-Si phase in SiMn. In addition, the almost pure single metallic phases were found to be Ti in FeTi, Nb in FeNb, and Si in FeSi. As the requirements on material properties increase, the effect of impurities in ferroalloys on the steelmaking process is increasingly becoming more important. The characteristic of inclusions (morphology, number, size, and composition) in ferroalloys investigated in three-dimensional after electrolytic extraction is a good method for studying the evolution of inclusions during steelmaking.

  • 127.
    Bi, Yanyan
    et al.
    KTH.
    Karasev, Andrey V.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Jönsson, Pär G.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Three-dimensional determinations of the non-metallic inclusions in different ferroalloys2014Konferensbidrag (Refereegranskat)
    Abstract [en]

    Ferroalloys are commonly used in the steel industry to alloy or deoxidize the steel during the secondary steelmaking process before casting. Depending upon the ferroalloy quality, the addition can also lead to a supply of deleterious inclusions to the liquid steel. Thus, the number, morphology, size and composition of inclusions in six different ferroalloys (FeTi, FeNb, FeSi, SiMn LCFeCr and HCFeCr) were investigated. This was done in three dimensions (3D) by using SEM in combination with EDS after electrolytic extraction of the ferroalloy samples. Moreover, statistics of extreme values (SEV) were used to determine the largest size of inclusions.

  • 128.
    Bi, Yanyan
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Karasev, Andrey Vladimirovich
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Jönsson, Pär G.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Evolution of Different Inclusions during Ladle Treatment and Continuous Casting of Stainless Steel2013Ingår i: ISIJ International, ISSN 0915-1559, E-ISSN 1347-5460, Vol. 53, nr 12, s. 2099-2109Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The inclusions and clusters in steel samples of two similar steel grades of high-silicon non-calcium treated (HSiNC) stainless steels were investigated and compared during ladle treatment and continuous casting. Samples of liquid steel and slag were taken at different stages of the ladle treatment and casting during two plant trials: Low Al steel (LAI) and High Al steel (HAI). After electrolytic extraction of the steel samples, characteristics of inclusions and clusters (such as morphology, composition, size and number) were investigated in three dimensions (3D) by SEM in combination with EDS. Moreover, the composition of typical inclusions and clusters was analyzed on a polished cross section of steel samples. Spherical (SP), irregular and regular (IR) inclusions and clusters (CL) were observed in the samples from both heats. It was found that the morphology and composition of inclusions and clusters in both heats were significantly changed during the ladle treatment and casting. Most of inclusions (44-98%) in a Low Al steel are MgO-CaO-SiO2-Al2O3 spherical inclusions. The compositions of IR inclusions and clusters in steel samples of a High Al steel were mostly MgO center dot Al2O3 spinet, but also the complex SP inclusions containing Al2O3-MgO-CaO-SiO2. In addition, phase stability diagram based on Darken's quadratic formalism and Redlich-Kister type polynomial was estimated for both heats at a non-infinite solution.

  • 129.
    Bigdeli, Sedigheh
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Termodynamisk modellering.
    Developing the third generation of Calphad databases: what can ab-initio contribute?2017Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Developing the third generation of Calphad databases with more physical basis valid within a wider temperature range is the aim of the present work. Atomistic scale (ab-initio) methods, particularly techniques based on DFT theory, are used for modelling dierent phenomena, so as to gauge the capacity for use in Calphad modelling. Several systems are investigated in this work for studying dierent phenomena, such as magnetism and vibration of atoms. In the case of pure elements (unaries), thermodynamic properties of Mn, Al and C are optimized in the whole temperature range by the help of new models. In addition, DFT results and specic characteristics of these elements are also used to develop models for describing magnetic properties and atomic vibrations. With regards to coupling between DFT and Calphad, the EMTO technique is used for determining the magnetic ground state of the metastable hcp phase in Fe and Mn, and the TU-TILD technique is used for modelling solid phases above the melting point. TU-TILD is also used for calculating thermodynamic properties of bcc Mn at nite temperatures. The same phenomena are investigated in higher-order systems, i.e. the binaries Fe-Mn and Mn-C. Thermodynamic properties and phase diagrams of these systems are assessed against experimental data. Moreover, the revised magnetic model is used for modelling magnetic properties in these systems.

    It is shown through this investigation that although the DFT methods are powerful tools for model development and for resolving discrepancies between dierent experimental datasets, they should not be overly-trusted. Caution must be taken when using DFT results, since the approximations and assumptions for computational implementations may cause some errors in the results. Moreover, implementing them into Calphad software as a connected methodology is not currently accessible due to the computational limitations.

    It is concluded that coupling between the DFT and Calphad approaches can currently be achieved by using DFT results as an input in Calphad modelling. This will help to improve them until they can be integrated into the Calphad approach by the progress of computational possibilities.

    One of the advantages of developing the third generation Calphad databases is the possibility of using the 0 K DFT results in Calphad modelling, since the new databases are valid down to 0 K. This has not been possible in the past, and such potential opens a new door to bring more physics into the Calphad approach.

  • 130.
    Bigdeli, Sedigheh
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Termodynamisk modellering.
    Korbmacher, Dominique
    Grabowski, Blazej
    Körmann, Fritz
    Duff, Andrew Ian
    Blomqvist, Andreas
    Neugebauer, Jörg
    DFT based calculations of thermodynamic properties for paramagnetic bcc-Mn at high temperaturesManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    In developing the third generation of Calphad databases, density-functional-theory methods are particularly important for validating physical models and for providing input data where experiment is unavailable. Since Cal-phad modelling needs data at finite temperatures additional sampling tech-niques are required, and the recently developed TU-TILD method is one such technique that allows for an efficient and accurate calculation of free energies. It is used in the present work for the complicated paramagnetic bcc phase of Mn. Our results show a good agreement with experimental data, validating that this method is well suited for calculating thermody-namic properties of magnetically complex and dynamically unstable phases as needed for Calphad modelling. It is also shown that a transition from bcc to the ω phase occurs below 1200 K.

  • 131.
    Bigdeli, Sedigheh
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Termodynamisk modellering.
    Qing, Chen
    Selleby, Malin
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Termodynamisk modellering.
    A new description for pure C; in developing the third generation of Calphad databases.Ingår i: Journal of Phase Equilibria and DiffusionArtikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    In connection to developing the third generation of Calphad databases a new thermodynamic description is presented for unary carbon. Models used in this work have more physical basis and are valid down to 0 K. The anisotropy in graphite, caused by weak Van der Waals inter-plane forces makes it difficult to fit the heat capacity data by a single Einstein tempera-ture for modelling the harmonic vibration of the atoms. By using multiple Einstein temperatures this problem is solved and a good agreement with the experimental data at low temperatures is achieved. Diamond is mod-eled using new models too, and the two-state model is used for modelling the liquid phase.

  • 132.
    Bigdeli, Sedigheh
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Termodynamisk modellering.
    Selleby, Malin
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Termodynamisk modellering. KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Metallografi.
    A thermodynamic assessment of the binary Fe-Mn system for the third generation of Calphad databases2017Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    In developing the third generation of Calphad databases, after having proper models for the unaries, the next step is to assess higher-order systems, i.e. binaries, ternaries etc. A new description for the Fe-Mn system is presented in this work, based on the Calphad approach. New models with a stronger physical basis are used to model Gibbs energy of the phases. For this purpose, the revised magnetic model is used to fit the magnetic properties versus the most recent experimental and DFT data. An acceptable magnetic phase diagram is reproduced, which results in a more reasonable fit for the phase diagram and will prevent possible artefacts in higher-order systems. The descriptions are valid down to 0 K, which make them very useful as an input for modelling phase transformations occurring at low temperatures.  

  • 133.
    Bigdeli, Sedigheh
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Zhu, L. -F
    Glensk, A.
    Grabowski, B.
    Lindahl, B.
    Hickel, T.
    Selleby, Malin
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    An insight into using DFT data for Calphad modeling of solid phases in the third generation of Calphad databases, a case study for Al2019Ingår i: Calphad, ISSN 0364-5916, E-ISSN 1873-2984, Vol. 65, s. 79-85Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In developing the next generation of Calphad databases, new models are used in which each term contributing to the Gibbs energy has a physical meaning. To continue the development, finite temperature density-functional-theory (DFT) results are used in the present work to discuss and suggest the most applicable and physically based model for Calphad assessments of solid phases above the melting point (the breakpoint for modeling the solid phase in previous assessments). These results are applied to investigate the properties of a solid in the superheated temperature region and to replace the melting temperature as the breakpoint with a more physically based temperature, i.e., where the superheated solid collapses into the liquid. The advantages and limitations of such an approach are presented in terms of a new assessment for unary aluminum.

  • 134.
    Bigdeli, Sedigheh
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Termodynamisk modellering.
    Zhu, Li-Fang
    Glensk, Albert
    Grabowski, Blazej
    Lindahl, Bonnie
    Hickel, Tilmann
    Selleby, Malin
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Termodynamisk modellering.
    An insight into using DFT data for Calphad modelling of solid phases in the third generation of Calphad databases, case study for Al2017Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

     In developing the next generation of Calphad databases, new models are used in which each term contributing to the Gibbs energy has a physical meaning. Harmonic vibrations of atoms are modelled using the Einstein temperature; anharmonic vibrations, electronic and magnetic contributions to the solid phases are represented by specific terms. The two-state model is used for the liquid phase. To continue the development, a new description for unary aluminum is presented in this work. In particular, finite temperature density-functional-theory (DFT) results are used to discuss and suggest the most applicable and physically based model for Calphad assessments of solid phases above the melting point. 

  • 135.
    Bilen, Idil
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Direct Reduced Iron Production from EAF Slags in Fixed Bed Furnace2013Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Electric arc furnace (EAF) slags are basic characteristic slags that include approximately 40 % iron oxide compounds. Iron oxide can be recycled and re-used in the process to decrease amount of waste product besides reducing loss of raw materials. According to result of survey performed by The European Association Representing Metallurgical Slag Producers and Processors (EUROSLAG) in 2010, 8.5 million tons of EAF slag is produced in Europe. High percentage of EAF slag is re-used in road construction as aggregate. However it can be re-cycled in the internal use for metallurgical processes as well. In order to re-use EAF slag in the process as a raw material, direct reduction is a new approach. Direct reduction is reduction of iron containing raw materials with gas or solid reductants without melting of charge. In this study, reduction conditions of 39 % Fe2O3 containing EAF slag in tube furnace was examined. As the reducing agent, metallurgical coke was used. EAF slag was milled and pelletized in raw material preparation step. Pellets were charged to fixed bed type tube furnace in a graphite boat at 1050, 1100 and 1150°C respectively with 150 and 200% of stoichiometrically required amount of metallurgical coke. 5, 10, 15, 30, 60, 90 and 120 minutes process durations were performed. Direct reduced pellets were milled to be characterized by using X-Ray Diffraction (XRD) and chemical analysis methods. Results indicate that increased temperature, process duration and stoichiometry have a positive impact on direct reduction of EAF slag in terms of iron metallization. 90 % metallization degree has been achieved as the result of the study with the process conditions of 200 % stoichiometry and 90 minutes process duration at 1150 °C.

  • 136.
    Bjurman, Martin
    et al.
    Studsvik Nuclear, Sweden.
    Forssgren, Björn
    Ringhals AB, Sweden.
    Efsing, Pål
    KTH, Skolan för teknikvetenskap (SCI), Hållfasthetslära (Inst.).
    Fracture mechanical testing of in service thermally aged cast stainless steel2016Ingår i: Fatigue and Fracture Test Planning, Test Data Acquisitions and Analysis, ASTM International, 2016, Vol. 1598, s. 58-80Konferensbidrag (Refereegranskat)
    Abstract [en]

    Embrittlement of Duplex Stainless Steels by thermal aging shortens the service life of structural components in Light Water Reactors (LWRs). This is an important issue when life extension programs are aiming at 60-80 years in service, as ductile failure is a design prerequisite. Cast and welded austenitic stainless steels, which contain some ferrite, are known to be affected by thermal aging. Historically, many LWR components of complex geometry have been cast in the Mo-containing quality CF8M. Aging is mainly attributed to two types of phase transformations occurring within the minor ferritic phase; Demixing of the ferrite by spinodal decomposition into Cr-rich a´ and Fe-rich a regions; and precipitation of G-phase, carbides and other secondary phases.

    The present program of two in-service aged pipe bend castings from the Pressurized Water Reactor (PWR) Ringhals 2 Steam Generator. These components are large castings of stainless steel quality CF8M. The manufacturing process produces a non-uniform microstructure with coarse ferrite and a high degree of directionality affecting properties as well as the methodology for testing.

    The materials were exposed to primary circuit PWR water for 72 kh at 291ºC and 325ºC, respectively, followed by 22 kh at a reduced service temperature.

    Fracture mechanical evaluation using the J-R technique at RT and 300ºC as well as instrumented Charpy-tests ranging from -196ºC to +400ºC are conducted. Effects of large microstructural heterogeneity and anisotropy from the casting and heat treating processes are tested and evaluated. The change of these parameters effect on aging embrittlement and fracture mechanisms within each phase as well as phase interaction are also studied.

  • 137.
    Bjurman, Martin
    et al.
    KTH. Studsvik Nuclear AB, Sweden.
    Lindgren, K.
    Thuvander, M.
    Ekström, P.
    Efsing, Pål
    KTH, Skolan för teknikvetenskap (SCI), Hållfasthetslära (Inst.).
    Microstructural evolution of welded stainless steels on integrated effect of thermal aging and low flux irradiation2018Ingår i: 18th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors, 2017, Springer International Publishing , 2018, Vol. Part F11, s. 703-710Konferensbidrag (Refereegranskat)
    Abstract [en]

    The combined effect of thermal aging and irradiation on cast and welded stainless steel solidification structures is not sufficiently investigated. From theory and consecutive aging and irradiation experiments, the effect of simultaneous low rate irradiation and thermal aging is expected to accelerate and modify the aging processes of the ferrite phase. Here, a detailed analysis of long-term aged material at very low fast neutron flux at LWR operating temperatures using Atom Probe Tomography is presented. Samples of weld material from various positions in the core barrel of the Zorita PWR are examined. The welds have been exposed to 280–285 °C for 38 years at three different neutron fluxes between 1 × 10−5 and 7 × 10−7 dpa/h to a total dose of 0.15–2 dpa. The aging of the ferrite phase occurs by spinodal decomposition, clustering and precipitation of e.g. G-phase. These phenomena are characterized and quantitatively analyzed in order to understand the effect of flux in combination with thermal aging.

  • 138.
    Björkblad, Anders
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg.
    On the prediction of crack propagation in cast steel specimens2005Ingår i: Competent Design by Castings: Improvements in a Nordic Project / [ed] Samuelsson, J; Marquis, G; Solin, J, ESPOO: TECHNICAL RESEARCH CENTRE FINLAND , 2005, Vol. 237, s. 251-272Konferensbidrag (Refereegranskat)
    Abstract [en]

    This investigation deals with the fatigue behaviour of cast steel with respect to defects, crack initiation, crack growth and material parameters. It constitutes the initial part of a larger work in cast materials. The main objectives have been to validate calculations made by FEM and Paris law with data from fatigue tests and to confirm material parameters for Pan's law. Furthermore, the results where put against calculations obtained from the fracture mechanic software AF-GROW. During the accomplishment some difficulties was experienced concerning the initiation of the crack, with result that there where just a few specimens suitable for evaluation by LEFM. However, some conclusions concerning the crack growth behaviour could yet be done. The results in general showed good correspondence, the results from AF-GROW included. Most divergences could be explained by residual stresses and, to some extent, the initiation problems.

  • 139.
    Björklund, Johan
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    A study of slag-steel-inclusion interaction during Ladle treatment2006Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The thesis is based on two supplements with two major objectives. In the first supplement equilibrium top slag-steel bulk and inclusions-steel bulk were investigated by comparison between calculated and measured oxygen activity values. This was done by applying different oxide activity models for slags combined with thermodynamic calculations. In the second supplement the inclusion composition is studied during the ladle refining process. The inclusion composition is related to top slag composition and other parameters during ladle

    treatment.

    The work was carried out by collecting data during well controlled sampling procedures at two different steel plants. Extensive inclusion analyses in Scanning Electron Microscope, SEM, were done. The data was used together with thermodynamics for a description of the interaction between slag-steel-inclusion interaction during ladle treatment.

    Evaluation of inclusion composition during the ladle refining have revealed that the majority of the inclusions belonged to the system Al2O3-CaO-MgO-SiO2 and showed a continuous composition change throughout the ladle refining process, from high Al2O3, via MgO-spinel to finally complex types rich in CaO and Al2O3. The final composition after vacuum treatment was found to be close to the top slag composition. Small process parameter changes and practical variations during ladle refining were proven to give large differences of the inclusion composition.

    Finally, it was concluded that equilibrium does not exist between top slag and steel bulk, with respect to oxygen, for the studied conditions. However, the equilibrium does exist between the steel bulk and inclusion.

  • 140.
    Björklund, Johan
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Thermodynamic Aspects on Inclusion Composition and Oxygen Activity during Ladle Treatment2008Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Two industrial studies and one set of lab scale trials have been done. In addition, a theoretical study has been done. The main focus has been on non metallic inclusion composition during the ladle refining operation in industrial steel production. Sampling has been done together with careful inclusion determination. The inclusion composition is related to different variables. In the industrial trials samples have been taken at different steps during the ladle refining period. Steel and slag composition as well as temperature and oxygen activity have been determined.

    The thesis is based on five supplements with different major objectives, all related to the inclusion composition. The equilibrium top slag-steel bulk and inclusions-steel bulk were investigated by comparison between calculated and measured oxygen activity values. The oxygen activity and relation to temperature has also been discussed as well as oxygen activity and temperature gradients. The effect of vacuum pressure on inclusion composition has been evaluated in a theoretical study as well as lab scale trials. The inclusion composition has been studied during the industrial ladle treatment process. The inclusion composition was related to top slag composition and other parameters during ladle treatment.

    The major findings in the thesis are the lack of equilibrium conditions with respect to top-slag and steel bulk before vacuum treatment. The inclusions have been found to be closer to equilibrium with the steel bulk. Al/Al2O3 equilibrium has been found to control the oxygen activity after Al-deoxidation. Evaluation of inclusion composition during the ladle refining has revealed that the majority of the inclusions showed a continuous composition change throughout the ladle refining process, from high Al2O3, via MgO-spinel to finally complex types rich in CaO and Al2O3. The final inclusion composition after vacuum treatment was found to be close to the top slag composition. Vacuum pressure has been found to have a theoretical effect on inclusion composition at very low pressures.

  • 141.
    Björklund, Johan
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Andersson, Margareta
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Jönsson, Pär
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Equilibrium between slag, steel and inclusions during ladle treatment: comparison with production data2007Ingår i: Ironmaking & steelmaking, ISSN 0301-9233, E-ISSN 1743-2812, Vol. 34, nr 4, s. 312-324Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The primary purpose of the investigation was to determine whether equilibrium conditions exist between slag and steel and inclusions and steel after silicon deoxidation and aluminium deoxidation. In doing so, the performance of three different models for predicting oxide component activities was also evaluated. The results from the oxide activity models were used to calculate oxygen activities in the steel melt. Industrial data such as steel, slag and inclusion component concentrations, as well as temperature, were used as input to the calculations. One general conclusion drawn was that although the results from the different models showed similar trends, the models did not predict the same actual values for specific calculations. Predicted theoretical equilibrium oxygen activity values were compared with plant measurements of oxygen activity. Here, it was found that the oxygen activity values pertaining to the equilibrium between steel and inclusions were higher than corresponding measured values. The calculations for the equilibrium between the top slag and steel melt, however, resulted in theoretical oxygen activity values considerably lower than corresponding measurements. It was thus concluded that equilibrium conditions did not exist between the top slag and the steel bulk with respect to oxygen. Overall, the models proved useful in predicting oxide activities, but the lack of equilibrium between top slag and molten steel made the calculation of oxygen activity difficult.

  • 142.
    Björklund, Johan
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Andersson, Margareta
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Jönsson, Pär
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    The Influence of Vacuum Treatment on Inclusion Composition: Laboratory Study2010Ingår i: High Temperature Materials and Processes, ISSN 0334-6455, E-ISSN 2191-0324, Vol. 29, nr 3, s. 189-202Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A series of lab scale trials have been carried out with the aim of investigating the effect of vacuum treatment on inclusion chemistry. A ball bearing steel grade (1.47 wt% Cr, 0.96 wt% C) has been melted in a controlled atmosphere in magnesia and alumina crucibles. A laboratory vacuum furnace, which makes it possible to carry out sampling during vacuum treatment, was used. Samples were taken before and during vacuum treatment. Thereafter, the inclusion compositions in the samples were determined using SEM in combination with EDS. The inclusions found were mainly sulphides containing both manganese and chromium. In addition to these, MgO-Al2O3 oxides were found with varying contents of calcium. Furthermore, a few, calcium sulphides were found. Additionally, it was possible to find a small difference in the average inclusion composition in the samples taken before and during vacuum. More specifically, it was seen that the composition of the inclusions becomes more sulphide-rich during vacuum treatment. The change of average inclusion composition was not as large as suggested from theoretical computations and oxides were found at the same extent during vacuum as before. Another finding was that the inclusions from the trial where an alumina crucible was used contained no magnesia, but that the inclusions contained magnesia when a magnesia crucible was used. Even though the effect of vacuum treatment on the inclusion compositions was found to be small, it was concluded that vacuum treatment could not to be neglected when studying inclusions influenced by top slag/metal reactions.

  • 143.
    Björklund, Johan
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Andersson, Margareta
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Jönsson, Pär
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    The Influence of Vacuum Treatment on Inclusion Composition: Theoretical Study2010Ingår i: High Temperature Materials and Processes, ISSN 0334-6455, E-ISSN 2191-0324, Vol. 29, nr 3, s. 179-187Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A theoretical study has been conducted into how inclusion composition is influenced by vacuum treatment. Software for computational thermodynamics has been used to simulate how the conditions in a steel melt changed as a result of a decreased pressure. A case study was made on a low sulphur bearing steel (1.4% Cr, 1.0%C). The calculations show the effect of sulphur, oxygen, carbon and temperature on precipitated phases in the steel melt. The result shows that at low pressure, formation of carbon monoxide takes place. For 5 ppm O and 10 ppm S the CO-gas becomes thermodynamically stable below 40 torr. Oxide phases will be reduced and CaS will be the stable phase.

  • 144.
    Björklund, Johan
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Andersson, Margareta
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Nzotta, Mselly
    Uddeholm Tooling AB.
    Jönsson, Pär
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    The Effect of Ladle Treatment on Inclusion Composition in Tool Steel Production2008Ingår i: Steel Research International, ISSN 1611-3683, Vol. 79, nr 4, s. 261-270Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An in-depth SEM-investigation of the inclusion composition change in the ladle refining process during tool steel production was done. Plant trials were carried out at Uddeholm Tooling AB in Hagfors, Sweden. A series of samples was taken during ladle refining, from deslagging through vacuum treatment. The goal was evaluating the effects of the top slag and other process parameters on the inclusion composition during ladle refining. The main conclusion was that normal variations in the process have a large influence on inclusion composition. Furthermore, it was concluded that the MgO content in the top slag had a large influence on the inclusion, composition throughout the whole ladle refining process. Also, the SiO2 content in the ladle slag originating from the EAF-slag, had a noticeable effect on the inclusions. The inclusions belonging to the system Al2O3-CaO-MgO-SiO2 showed a continuous composition change throughout the ladle refining process, from high Al2O3, via MgO-spinel to finally complex types rich in CaO and Al2O3.

  • 145.
    Björklund, Johan
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Miki, Takahiro
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Andersson, Margareta
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Jönsson, Pär
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad processmetallurgi.
    Effect of Temperature on Oxygen Activity during Ladle Treatment2008Ingår i: ISIJ International, ISSN 0915-1559, E-ISSN 1347-5460, Vol. 48, nr 4, s. 438-445Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The effect of temperature on oxygen activity in steel was studied in plant trials where temperature and oxygen activity were measured at two depths and at the same time during different parts of ladle refining. The results show that large temperature gradients exist towards the surface of the steel melt for the sampling occasion when no slag is present on the steel surface, as can be expected. It was also observed that the oxygen activity is higher in the lower measurement position than in the upper during the majority of the ladle refining. This is explained by the oxygen activity's temperature dependence. By using the data from this study and previously reported plant trials it was shown that Si-SiO2 or Al-Al2O3 equilibrium controls the oxygen activity.

  • 146.
    Björn, Linnéa
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Forslin, Malin
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Continuous Measurements of the Pig-Iron Temperature2012Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    This report is about continuous temperature measurements of pig-iron at tapping from blast furnace 2 in Oxelösund, SSAB. Nowadays the temperature is only checked once at every tapping. The purpose of this project is to see if the process stability increases by continuously knowing the temperature and to compare the costs of this new technique with the technique used today. Possible savings due to less consumption of coke/coal if the silicon amount and the temperature are closer to their aim values will be regarded and if as little steam consumption as possible are used. The process stability can be divided into different sub goals.

    The ordinary measuring techniques were investigated as a part of the main goal; such as the ordinary measured temperature, the pig-iron and slag samples.

    The new continuous temperature measuring technique was compared with the ordinary temperature measurement and investigations of the life length were done. How representative the pig-iron and slag samples are, when taking them at the time they are today, are also looked into.

    The continuous measured temperature showed around 0,37 % higher temperature than the ordinary measured temperature. The pig-iron and slag samples should be taken as they are today, for mainly safety aspects.

    By using continuous temperature measurement, some of the sub goals can be achieved for a more stable process. The economy on the other hand has shown that large savings can be done by using this continuous temperature method due to a more stable process. This is mainly because of a decrease in steam usage in the experimental period. By regarding only the material of the methods the continuous temperature equipment is a bit more expensive, but the savings are much larger so the continuous temperature method is beneficial. With time this method could probably improve the process stability even more since the operators will deal with the information and the probe better.

  • 147. Blanter, M. S.
    et al.
    Dmitriev, V. V.
    Mogutnov, B. M.
    Ruban, Andrei V.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Interaction of interstitial atoms and configurational contribution to their thermodynamic activity in V, Nb, and Ta2017Ingår i: Physics of metals and metallography, ISSN 0031-918X, E-ISSN 1555-6190, Vol. 118, nr 2, s. 105-112Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The pairwise interaction energies of O–O and N–N in bcc metals of group VB, which were calculated earlier using first-principles methods, have been employed to analyze the effect of the interatomic interactions on the configurational contribution to the thermodynamic activity. The strong effect of interstitial- interstitial interaction has been shown. The configurational contribution grows in the row (Nb–N) → (V–N) → (Ta–N) → (Nb–O) → (V–O) → (Ta–O), which is caused by a weakening of the mutual attraction of interstitial atoms in these solid solutions. The strong repulsion that characterizes the majority of coordination shells only weakly affects the thermodynamic activity. The character of the temperature dependence of the configurational contribution is defined by the strength of the mutual attraction of the interstitial atoms, i.e., upon strong attraction, the contribution increases with increasing temperature (Nb–N, V–N, Ta–N, and Nb–O) and, upon weak attraction, it decreases (V–O and Ta–O).

  • 148. Bleskov, I. D.
    et al.
    Smirnova, E. A.
    Vekilov, Y. K.
    Korzhavyi, Pavel A.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad materialfysik.
    Johansson, Börje
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad materialfysik.
    Katsnelson, M.
    Vitos, Levente
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad materialfysik.
    Abrikosov, I. A.
    Isaev, E. I.
    Ab initio calculations of elastic properties of Ru1-xNixAl superalloys2009Ingår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 94, nr 16Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Ab initio total energy calculations based on the exact muffin-tin orbitals method, combined with the coherent potential approximation, have been used to study the thermodynamical and elastic properties of substitutional refractory Ru1-xNixAl alloys. We have found that the elastic constants C' and C11 exhibit pronounced peculiarities near the concentration of about 40 at. % Ni, which we ascribe to electronic topological transitions. Our suggestion is supported by the Fermi surface calculations in the whole concentration range. Results of our calculations show that one can design Ru-Ni-Al alloys substituting Ru by Ni (up to 40 at. %) with almost invariable elastic constants and reduced density.

  • 149. Bogdanov, V. I.
    et al.
    Popov, V. A.
    Portnoi, V. K.
    Ruban, Andrei V.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad materialfysik.
    Chemical and deformational interactions in solid solution of carbon in nickel2012Ingår i: Physics of metals and metallography, ISSN 0031-918X, E-ISSN 1555-6190, Vol. 113, nr 9, s. 831-835Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A first-principles stuy of ordering phenomena in hcp interstitial solid solutions of oxygen and nitrogen in Ti, Zr and Hf has demonstrated that the dominant contributions to the interaction energy of interstitial atoms are of chemical nature; thus, it is necessary to modify the previously established concepts about the priority role of deformational interactions in interstitial solutions. We have continued studies of the role of chemical and deformational interactions of interstitial atoms by the example of solid solutions of carbon in nickel. The results obtained also confirm a significant role of chemical interactions between carbon atoms in these solid solutions. The results were compared with the experimental data on the enthalpy of carbon dissolution in nickel and on the coefficient of solutal expansion of the lattice.

  • 150. Bogdanov, V. I.
    et al.
    Popov, V. A.
    Portnoi, V. K.
    Ruban, Andrei V.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad materialfysik.
    First-principles investigations of interatomic interactions in Ni3Al alloyed by interstitial and substitutional impurities2013Ingår i: Physics of metals and metallography, ISSN 0031-918X, E-ISSN 1555-6190, Vol. 114, nr 3, s. 191-196Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    First-principles calculations of the total energy of interstitial and substitutional solid solutions in intermetallic compound Ni3Al were performed based on methods using Vienna ab-initio simulation package (VASP). The results of the calculations for interstitial solutions of carbon in Ni3Al confirmed the priority role of chemical interactions over deformational ones for the nearest neighbors. We attempted to use first-principles methods of calculation of the deformation interaction and continuum approaching in the theory of solutions to calculate coefficients of the concentration changes of the lattice spacing. Comparison of the calculation results with experimental data of substitutional impurities in Ni3Al has shown that the proposed method can aid in the study of the distribution of impurity atoms on the sublattices of the ordered phases, intermetallic compounds. We have proposed a method of calculating the partial molar volume of impurity in interstitial solid solutions.

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