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  • 51.
    Olupot, Peter Wilberforce
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Mechanical Metallurgy.
    Jonsson, Stefan
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Mechanical Metallurgy.
    Byaruhanga, Joseph K.
    Study of Glazes and Their Effects on Properties of Triaxial Electrical Porcelains from Ugandan Minerals2010In: Journal of materials engineering and performance (Print), ISSN 1059-9495, E-ISSN 1544-1024, Vol. 19, no 8, p. 1133-1142Article in journal (Refereed)
    Abstract [en]

    Kaolin, ball clay, feldspar, and sand were collected from deposits in Uganda, milled and sieved to particle sizes of 45, 45, 53, and 25 μm, respectively. Three porcelain bodies and five glazes were formulated from them. The glazes were applied on porcelain specimens and subsequently evaluated for their effects on properties of porcelain samples. The formulated specimens were investigated using dilatometry, Steger test, FEG-SEM, XRD, 4-point bending, dielectric strength, and fracture toughness tests. A porcelain specimen consisting of 68% SiO2, 19% Al2O3, 4.7% K2O, and a glaze RO:0.57Al2O3:4.86SiO2 exhibited MOR of 105 MPa with Weibull modulus of 5.6 and a dielectric strength of 18 kV/mm upon firing at a heating rate of 6 °C/min to 1250 °C and holding for 2 h. The microstructure of the high-strength specimen exhibited round mullite needles, quartz, and glass. Holding samples for 2 h at peak temperature resulted in a 22% increase in MOR compared to 1 h holding. Glazing further improved strength by 67% for the best sample. Compressive stresses in glaze contributed to the strengthening effect. The dielectric and mechanical strength values obtained qualify the formulated sample for application in electrical insulation.

  • 52.
    Tehler, Matilda
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Jonsson, Stefan
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    A Material Model for Simulating Volume Changes during Phase Transformations2007In: Proceedings of the COMSOL Users Conference 2007 Grenoble, 2007, p. 648-653Conference paper (Refereed)
    Abstract [en]

    The present work describes the first steps in creating a robust material model able to predict volume changes due to thermal expansion and phase transformations. A dilatometer test is simulated starting from room temperature with an original microstructure constituting a mixture of ferrite and pearlite. During heating, the structure transforms to austenite, which upon quenching will transform into martensite. Both thermal expansion and phase transformations will give rise to volume changes which are modeled in the present work. After adjusting the model parameters to experimental data, a simulation of a dilatometer test is favorably compared to experimental data. The successful reproduction of volume changes allows accurate simulations of distortions during industrial heat treatments, which is the aim of the on-going research.

  • 53.
    Tehler, Matilda
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Jonsson, Stefan
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Modeling Bainitic Transformation in a Case Hardening SteelManuscript (preprint) (Other academic)
    Abstract [en]

    The paper contains experimental and simulated results for the phase transformation of austenite to bainite during isothermal conditions. A case hardening steel is studied at four carbon contents, using a dilatometer. The bainite fraction is calculated by time integration of a time-independent transformation rate equation, derived from Austin-Rickett kinetics. Simulations in COMSOL Multiphysics produces bainite fractions correlating to experiments.

  • 54.
    Tehler, Matilda
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Jonsson, Stefan
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Modeling Volume Changes during Cooling of Case Hardening SteelsManuscript (preprint) (Other academic)
    Abstract [en]

    Results regarding martensitic and bainitic phase transformations, heat expansion behaviors and phase transformation strains during constant heating and cooling rates are presented. Equations describing heat expansion behavior, phase transformation strain and martensitic formation are evaluated as functions of carbon content. The equation for bainitic transformation described in Supplement 2 is used during constant cooling rates for two different case hardening steels. COMSOL Multiphysics is used to simulate experiments, producing good agreement between experimental and simulated dilatometer curves.

  • 55.
    Thibblin, Anders
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.). Scania CV AB.
    Jonsson, Stefan
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Influence of microstructure on thermal cycling lifetime and thermal insulation properties of yttria-stabilized zirconia thermal barrier coatings for diesel engine applications2018In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 350, p. 1-11Article in journal (Refereed)
    Abstract [en]

    Thermal barrier coatings (TBCs) may improve the fuel efficiency of heavy-duty diesel engines by reducing heat losses. A combination of durability, low thermal conductivity, and high directional hemispherical reflectance is required for a TBC in the combustion chamber. These properties are evaluated for yttria-stabilized zirconia coatings, produced using atmospheric plasma spraying (APS) and plasma spray–physical vapour deposition (PS-PVD). The influences of different types of microstructure and metallic coatings on the surface are studied. APS coatings with segmentation cracks and PS-PVD coatings with columnar microstructure have the best thermal cycling lifetime, while nanostructured and conventional APS coatings have the lowest thermal conductivities. The nanostructured APS coating has the highest reflectance at low temperatures, while the columnar PS-PVD coating has the highest reflectance at elevated temperatures. It is further demonstrated that a thin silver layer improves the reflectance of a dense, segmented APS YSZ coating.

  • 56.
    Thibblin, Anders
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.). Scania CV AB.
    Jonsson, Stefan
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Mechanical Metallurgy.
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Influence of microstructure on thermal cycling lifetime, thermal insulation, and mechanical properties of yttria-stabilized zirconia thermal barrier coatingsIn: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347Article in journal (Refereed)
    Abstract [en]

    Thermal barrier coatings (TBCs) may improve the fuel efficiency of heavy-duty diesel engines by reducing heat losses. A combination of durability, low thermal conductivity, and high reflectance is required for a TBC in the combustion chamber. These properties are evaluated for yttria-stabilized zirconia coatings, produced using atmospheric plasma spraying (APS) and plasma spray–physical vapour deposition (PS-PVD). The influences of different types of microstructure and reflective metallic coatings on the surface are studied. APS coatings with segmentation cracks and PS-PVD coatings with columnar microstructure have the best thermal cycling lifetime, while nanostructured and conventional APS coatings have the lowest thermal conductivities. The nanostructured APS coating has the highest reflectance at low temperatures, while the columnar PS-PVD coating has the highest reflectance at elevated temperatures. It is further demonstrated that a thin silver layer improves the reflectance of a dense, segmented APS YSZ coating.

  • 57.
    Thibblin, Anders
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.). Scania CV AB.
    Kianzad, Siamak
    Scania CV AB.
    Jonsson, Stefan
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Mechanical Metallurgy.
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Running-in Behaviour of Thermal Barrier Coatings in the Combustion Chamber of a Diesel EngineIn: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347Article in journal (Refereed)
    Abstract [en]

    Thermal barrier coatings (TBCs) have the potential to improve the fuel efficiency of heavy-duty diesel engines by reducing heat losses. A method for in-situ measurement of heat flux from the combustion chamber of a heavy-duty diesel engine has been developed and was used to study the running-in behaviour of different TBC materials and types of microstructures. The in situ measurements show that the initial heat flux was reduced by up to 4.7 % for all investigated TBCs compared to a steel reference, except for an yttria-stabilized zirconia (YSZ) coating with sealed pores that had an increase of 12.0 % in heat flux. Gd2Zr2O7 had the lowest initial value for heat flux. However, running-in shows the lowest values for YSZ after 2–3 h. Potential spallation problems were observed for Gd2Zr2O7 and La2Zr2O7.

  • 58.
    Thibblin, Anders
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.). Scania CV AB.
    Kianzad, Siamak
    Jonsson, Stefan
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Mechanical Metallurgy.
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Running-in behaviour of thermal barrier coatings in the combustion chamber of a diesel engine2019In: Proceedings of the Institution of mechanical engineers. Part D, journal of automobile engineering, ISSN 0954-4070, E-ISSN 2041-2991Article in journal (Refereed)
    Abstract [en]

    Thermal barrier coatings have the potential to improve the fuel efficiency of heavy-duty diesel engines by reducing heat losses. A method for in-situ measurement of heat flux from the combustion chamber of a heavy-duty diesel engine has been developed and was used to study the running-in behaviour of different thermal barrier coating materials and types of microstructures. The in-situ measurements show that the initial heat flux was reduced by up to 4.7% for all investigated thermal barrier coatings compared to a steel reference, except for an yttria-stabilized zirconia coating with sealed pores that had an increase of 12.0% in heat flux. Gd2Zr2O7 had the lowest initial value for heat flux. However, running-in shows the lowest values for yttria-stabilized zirconia after 2?3?h. Potential spallation problems were observed for Gd2Zr2O7 and La2Zr2O7.

  • 59.
    Tomkowski, Robert
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Jonsson, Stefan
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Materials Processing.
    Lundin, Per
    Stresstech Oy.
    Nerman, Peter
    Scania CV AB.
    Penetration depth investigation of Barkhausen noise signal for case-hardened components2017Conference paper (Refereed)
    Abstract [en]

    Non-destructive testing of layer properties in machine part loading, has greatly improved over the last 20 years. One of those NDT methods is Barkhausen Noise Analysis (BNA). The BNA-method is utilized to assess changes in the surface layer of ferromagnetic materials, especially for monitoring changes in hardness and residual stresses. The BNA-method works on the interaction between the external magnetic field and the ferromagnetic material. The reorganizations of the magnetic domains and the formation of an internal magnetic field are registered by the sensor. The magnitude of the registered signal and its parameters depends on many factors. Many of them are non-correlated, while others are strongly correlated. One can easily show that the set of factors affecting the Barkhausen signal has more than 200 components, including interactions between factors. Combination of all this factor results in material response for external magnetization. However, the effect of all factors can be changed by so called skin effect, where with the use of low frequency material is magnetized deeper than with higher frequency. Nevertheless, depth from which signal is registered, generated by material, does not exactly overlap magnetization depth. This so-called penetration depth is depended on both full material characteristics and magnetization parameters. Therefore, in this publication authors investigated real response of measured Barkhausen noise signal in relation to mentioned conditions.

  • 60.
    Xiang, Shengmei
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Jonsson, Stefan
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Zhu, Baohua
    Scania CV AB.
    Odqvist, Joakim
    KTH, Superseded Departments (pre-2005), Materials Science and Engineering.
    Comparison of the high-temperature corrosion-fatigue resistance of cast alloys for exhaust manifoldsManuscript (preprint) (Other academic)
    Abstract [en]

    The corrosion fatigue behavior, fatigue resistance and corrosion resistance of four materials used in exhaust manifolds have been evaluated through conducting low-cycle fatigue tests at 800oC in synthetic exhaust and argon atmospheres as well as oxidation tests in the exhaust atmosphere. The four materials are two ferritic ductile cast irons SiMo51 and SiMo1000, one austenitic ductile cast iron Ni-resist D5S and one austenitic cast stainless steel HK30. Quantitative material rankings were given for the four materials in the two atmospheres through comparing the corresponding e-N and S-N curves. The crack growth mechanisms of the austenitic materials were studied in detail in the paper. Brittle intermetallic phases have been found in both materials but observed to have different levels of impact on their corrosion fatigue properties. The Ni-, Mn-, Si-rich intermetallic phase found in D5S greatly affects both fatigue and corrosion behavior of this material. However, the Fe-,Cr-rich sigma phase shows an insignicant impact as the crack growth path only occasionally follow the distribution pattern. In addition, severe oxide spallation was found in D5S leading to a rapid weight loss during the oxidation test.

  • 61.
    Xiang, Shengmei
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Zhu, Baohua
    Scania CV AB.
    Jonsson, Stefan
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    High-Temperature Corrosion-Fatigue Behavior of Ductile Cast Irons for Exhaust Manifolds Applications2018In: Materials Science Forum, ISSN 0255-5476, E-ISSN 1662-9752, Vol. 925, p. 369-376Article in journal (Refereed)
    Abstract [en]

    In the present study, low-cycle fatigue (LCF) tests and oxidation tests in controlled atmospheres are carried out at 800ºC on two ductile cast irons SiMo51 and SiMo1000. The LCF tests are conducted in argon and synthetic exhaust gas, whereas oxidation tests are carried out in the latter atmosphere. S-N curves and weight-gain curves are presented. The crack growth mechanisms and oxidation mechanisms are investigated, as well as the synergistic effects. A surprising finding of increased fatigue resistance in the oxidizing atmosphere is partly explained.

  • 62.
    Zeng, Zhipeng
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Jonsson, Stefan
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Roven, Hans J.
    The effects of deformation conditions on microstructure and texture of Commercially Pure Ti2009In: Acta Materialia, ISSN 1359-6454, E-ISSN 1873-2453, Vol. 57, no 19, p. 5822-5833Article in journal (Refereed)
    Abstract [en]

    Electron backscattered diffraction is employed to explore the dependence of deformation reduction, strain rate and temperature on microstructure and texture evolution of CP Ti after hot compression tests. It is found that {10-12} twinning only occurs at the early stage of deformation. As the strain increases, the {10-12} twinning is suppressed while {10-11} twinning appears. Three peaks are found in the misorientation frequency-distribution corresponding to basal fiber texture, {10-11} and {10-12} twinning, respectively. The data for the stable subgrain size and amount of {10-11} twins are separated into two groups at logZ = 13. Above this value, twinning is observed and the subgrain size is much finer, < 3μm. It is concluded that the presence of {10-11} twinning is the key factor for effectively reducing the deformed grain size. After deformation, three (0001) texture components can be found, one close to the compression direction, CD, one 10~30° to CD and another 45° to CD.

  • 63.
    Zeng, Zhipeng
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Mechanical Metallurgy.
    Jonsson, Stefan
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Roven, Hans J.
    Zhang, Yanshu
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Mechanical Metallurgy.
    Modeling the flow stress for single peak dynamic recrystallization2009In: MATERIALS & DESIGN, ISSN 0264-1275, Vol. 30, no 6, p. 1939-1943Article in journal (Refereed)
    Abstract [en]

    A model is developed to predict the flow stress for single peak dynamic recrystallization during hot working based on the analysis of the mechanism of the process. The model reveals the dependence of flow stress on strain, strain rate, temperature and microstructure. The flow stress in the recrystallized zone is derived by an integral with the recrystallized volume fraction as the variable. The correlation between the microscopic variable and flow stress is investigated with the model. The performance of the model is evaluated through application on magnesium alloy AZ31D. The mean error of flow stress between the experimental and predicted results is examined. Good agreement between the predicted and experimental data is achieved. All mean errors are between −5.9% and 6.7%.

  • 64.
    Zeng, Zhipeng
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Mechanical Metallurgy.
    Jonsson, Stefan
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Mechanical Metallurgy.
    Zhang, Yanshu
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Mechanical Metallurgy.
    Constitutive equations for pure titanium at elevated temperatures2009In: Materials Science & Engineering: A, ISSN 0921-5093, E-ISSN 1873-4936, Vol. 505, no 1-2, p. 116-119Article in journal (Refereed)
    Abstract [en]

    Isothermal compression tests were conducted on pure titanium using a Gleeble 1500 thermal simulator under constant strain rates of 0.001, 0.01, 0.1 and 1.0/s and at deformation temperatures ranging from 673 to 973 K up to a 60% height reduction of the sample. The high temperature deformation behaviour of pure titanium was characterized based on an analysis of the stress–strain curves. A set of constitutive equations for pure titanium were proposed by employing an Arrhenius-type equation. Material constants, A, β and activation energy Q, were found to be functions of strain. The equations revealed the dependence of flow stress on strain, strain rate and temperature. In order to evaluate the accuracy of the deformation constitutive equations, the mean errors of flow stress between the experimental data and predicted results were plotted. The results show that there is a close agreement between the predicted and experimental stress–strain curves.

  • 65.
    Zeng, Zhipeng
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Mechanical Metallurgy.
    Zhang, Yanshu
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Mechanical Metallurgy.
    Jonsson, Stefan
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Mechanical Metallurgy.
    Deformation behaviour of commercially pure titanium during simple hot compression2009In: Materials and Design, ISSN 0261-3069, Vol. 30, no 8, p. 3105-3111Article in journal (Refereed)
    Abstract [en]

    Commercially pure titanium (CP Ti), grade II, is subjected to hot compression at temperatures ranging from 673 to 973 K with 50 K intervals and strain rates of 0.001, 0.01, 0.1 and 1/s up to 60% height reduction. By analysing work hardening rate vs. flow stress, the deformation behaviour can be divided into three groups, viz. three-stage work hardening, two-stage work hardening and flow softening. By plotting the data in a T vs. log(strain rate) diagram, the present and previous data fall into three distinct domains which can be separated by two distinct values of the Zener–Hollomon parameter. The microstructure after deformation is characterized by optical microscopy and electron back scattered diffraction. The formation of {10-11} twins is related to the Zener–Hollomon parameter. Geometric dynamic recrystallization seems most appropriate when describing the grain refinement process of CP Ti during hot compression.

  • 66.
    Zeng, Zhipeng
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Mechanical Metallurgy.
    Zhang, Yanshu
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Mechanical Metallurgy.
    Jonsson, Stefan
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Mechanical Metallurgy.
    Microstructure and texture evolution of commercial pure titanium deformed at elevated temperatures2009In: Materials Science & Engineering: A, ISSN 0921-5093, E-ISSN 1873-4936, Vol. 513, p. 83-90Article in journal (Refereed)
    Abstract [en]

    Microstructure and texture evolution of commercial pure titanium were investigated by electron backscattered diffraction (EBSD) after compression tests at elevated temperatures. The basal planes of both the fine and coarse grains in the deformed samples tend to rotate from the initial orientations, perpendicular to the compression axis, to an inclination of 45°. The Schmid factor is used to analyse how the individual slip systems activate and how their activities evolve under various deformation conditions. After deformation, the distribution frequency of the misorientation angles shows that the low angle grain boundaries increased dramatically while the high angle grain boundaries decreased. In particular, after deformation at 723 K and 0.1/s, a peak around 50–60° in the misorientation frequency-distribution is found, which is due to {10-11} twinning. The analysis of the deformed microstructure indicates that dynamic recovery is the dominant deformation mechanism for commercial pure titanium when subjected to the investigated deformation conditions.

  • 67.
    Öberg, Christian
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Rablbauer, Ralf
    Volkswagen AG, Wolfsburg, Germany..
    Zhu, Baohua
    Scania, Helsingborg, Sweden..
    Jonsson, Stefan
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Monotonic and Cyclic Creep of Cast Materials for Exhaust Manifolds2019In: SAE International Journal of Materials & Manufacturing, ISSN 1946-3979, E-ISSN 1946-3987, Vol. 12, no 2, p. 149-162Article in journal (Refereed)
    Abstract [en]

    Cast materials are creep tested between 600 and 900 degrees C using three methods: (i) tensile testing at different strain rates, (ii) stress relaxation during thermal cycling and (iii) traditional creep tests at constant load. Comparisons are made between fast and slow methods and between monotonic and cyclic deformation modes. The tested materials, SiMo51, SiMo1000, Ni-resist D5S and HK30, are used for exhaust manifolds in heavy-duty diesel engines. The fast and cheap methods, (i) and (ii), were used on all materials, while the tedious and costly method, (iii), was used on SiMo51 only. The creep rates from monotonic tensile tests and stress relaxations during thermal cycling agree well. There is no difference between monotonic and cyclic creep rates, and cyclic rates are practically unchanged with the number of thermal cycles. No or small differences in creep rates are observed when comparing tension and compression, although three of the materials include large graphite nodules. At 700 degrees C, a Norton plot for SiMo51 shows coinciding results for tensile test and compressive stress relaxations, whereas the minimum creep rates from constant load tests fall one order of magnitude lower, but with the same slope. For all materials, the Norton creep parameters are evaluated with accurate reproduction of the experimental data. For HK30, two sets of parameters are needed because of deformation hardening.

  • 68.
    Öberg, Christian
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Tjernberg, Anders
    Scania CV.
    Rablbauer, Ralf
    Volkswagen.
    Jonsson, Stefan
    KTH, School of Industrial Engineering and Management (ITM).
    Monotonic and Cyclic Creep of Exhaust Manifold Materials and their effects on Predicted Thermo-mechanical Fatigue LifeManuscript (preprint) (Other academic)
    Abstract [en]

    Creep properties of SiMo51, SiMo1000, Ni-resist D5S and HK30, materials used for exhaust manifolds in heavy-duty diesel-engines, are examined by three methods; sequential tensile tests at high temperature, varying the strain rate; relaxation of stresses and strains during isothermal holds of thermal cycling with fixed grips; and traditional creep testing. The results for tensile tests and relaxations coincide while the creep tests show values, one order of magnitude lower.

    The creep can be modelled by Norton’s law and the cyclic influence, including strain reversals, is low. Simulations with/without taking creep into account show that predicted fatigue life for an exhaust manifold, subjected to engine tests with cycling between hot and cold gases, generally increase, with a few exceptions in some points, and that critical spots of low fatigue life are removed because of reduced mean stresses.

  • 69.
    Öberg, Christian
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Zhu, B. H.
    Jonsson, Stefan
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Plastic deformation and creep of two ductile cast irons, simo51 and simo1000, during thermal cycling with large strains2018In: 11th International Symposium on the Science and Processing of Cast Iron, SPCI-XI 2017, Trans Tech Publications, 2018, Vol. 925, p. 361-368Conference paper (Refereed)
    Abstract [en]

    Cyclic deformations of two ferritic, ductile cast irons, SiMo51 and SiMo1000, were studied in air and Ar using a new method, SRTC (stress relaxation with thermal cycling). Locked specimens were thermally cycled up to 800 °C with isothermal holds, varying temperature interval, heating/cooling rates and hold times. A description of the mechanical response to thermal cycling of a locked specimen is given.

  • 70.
    Öberg, Christian
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering. 8912104273.
    Zhu, Baohua
    Scania CV.
    Jonsson, Stefan
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Plastic deformation and creep of two ductile cast irons, SiMo51 and SiMo1000, during thermal cycling with large strainsIn: Materials Science Forum, ISSN 0255-5476, E-ISSN 1662-9752Article in journal (Refereed)
    Abstract [en]

    Cyclic deformations of two ferritic, ductile cast irons, SiMo51 and SiMo1000, were studied in air and Ar using a new method, SRTC (stress relaxation with thermal cycling). Locked specimens were thermally cycled up to 800 °C with isothermal holds, varying temperature interval, heating/cooling rates and hold times. A description of the mechanical response to thermal cycling of a locked specimen is given.

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