Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Hot Working Behaviour of Cast Metal Samples
KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Materials Processing.
2009 (English)Report (Other academic)
Place, publisher, year, edition, pages
2009.
Series
TRITA-MG, ISSN 1104-7127 ; 2009:05
National Category
Metallurgy and Metallic Materials
Identifiers
URN: urn:nbn:se:kth:diva-10033OAI: oai:DiVA.org:kth-10033DiVA: diva2:201542
Note

QC 20100803

Available from: 2009-03-05 Created: 2009-03-05 Last updated: 2016-12-20Bibliographically approved
In thesis
1. On Peritectic Reactions and Transformations and Hot Forming of Cast Structures
Open this publication in new window or tab >>On Peritectic Reactions and Transformations and Hot Forming of Cast Structures
2009 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

This thesis deals with peritectic reactions and transformations that occur during the solidification of many alloys. Peritectics are believed to be a major cause of crack-formation in many steels, thus, good knowledge of the mechanisms by which these phenomena occur is essential for preventing such defects. The thesis also handles the behaviour of metals, in particular cast structures, during hot forming. Grain size and microstructure are of most importance in determining the strength, toughness and performance of a steel. For achieving enhanced mechanical and microstructural properties, good understanding of the phenomena occurring during hot forming is required.

Peritectic reactions and transformations were studied in Fe-base and steel alloys through differential thermal analysis (DTA) experiments and micrographic investigation of quenched DTA samples. The effect of the ferrite/austenite interface strain during the peritectic reaction on equilibrium conditions was thermodynamically analysed, and the results were related to temperature observations from DTA experiments conducted on Fe-base alloys and low-alloy steels. Massive transformations from ferrite to austenite were observed in the micrographs of a number of quenched low-alloy steel samples and it was proposed that these transformations are uncontrolled by diffusion, and occur in the solid state as a visco-plastic stress relief process. DTA study of an austenitic stainless steel indicated that the alloy can exhibit primary precipitations to either ferrite or austenite. A continuously-cast breakout shell of the steel was analyzed and it was suggested that the observed irregularities in growth were due to alternating precipitations of ferrite and austenite; parts of the shell with higher ratios of primary-precipitated ferrite shrink in volume at the peritectic temperature and experience reduced growths.

An experimental method for studying the behaviour of metals during hot forming developed, and hot compression tests were conducted on cast copper and ball-bearing steel samples. Flow stress curves were obtained at varying temperatures and strain rates, and the results showed good agreement with earlier observations reported in literature. Micrographic analysis of quenched samples revealed variations in grain size and a model was fitted to describe the grain size as a function of deformation temperature and strain.

Solidification growth during continuous casting of stainless steel and copper was numerically modelled. A varying heat transfer coefficient was proposed to approximate the experimentally measured growth irregularities in the continuously-cast stainless steel breakout shell. Solidification growth of pure copper was also modelled in the Southwire continuous casting process. Temperature measurements from the chill mould were used to approximate the temperature gradient and the heat extraction from the solidifying strand, and the results were used in a two-dimensional model of solidification.

 

 

Place, publisher, year, edition, pages
Stockholm: KTH, 2009. 34 p.
Series
Trita-MG, ISSN 1104-7127 ; 2009:02
Keyword
peritectic reactions, massive transformations, thermal analysis, Fe-base alloys, steels, growth irregularities, hot forming, compression testing, flow stress, grain size.
National Category
Metallurgy and Metallic Materials Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:kth:diva-10006 (URN)978-91-7415-242-5 (ISBN)
Public defence
2009-03-27, F3, Lindstedtsvägen 26, KTH, 13:00 (English)
Opponent
Supervisors
Note
QC 20100803Available from: 2009-03-04 Created: 2009-03-02 Last updated: 2010-08-03Bibliographically approved

Open Access in DiVA

No full text

Search in DiVA

By author/editor
Sanet, JanNassar, HaniFredriksson, Hasse
By organisation
Materials Science and EngineeringMaterials Processing
Metallurgy and Metallic Materials

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 116 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf