Isothermal martensite formation at sub-zero temperatures

Allan Stojko, Mikkel Fougt Hansen, Jan Slycke, Marcel A. J. Somers

Research output: Chapter in Book/Report/Conference proceedingArticle in proceedingsResearchpeer-review

Abstract

Sub-zero treatment of steels with an Mf below 0°C relies (partly) on a continuation of the martensite formation. The present work reports on the observation of isothermal martensite formation in the sub-zero temperature regime for two steels: AISI 1070 and AISI 52100. Samples were austenitized, quenched in oil, and thereafter investigated with vibrating sample magnetometry, which allows a quantitative assessment of the fraction of retained austenite as a function of the sub-zero temperature and time. Isothermal martensite formation was observed on interrupting the continuous cooling (5 K/min) at temperatures in the range of 80-233 K. The kinetics of isothermal martensite formation depends strongly on the temperature and can be described by Johnson-Mehl-Avrami-Kolmogorov kinetics. Isothermal experiments with dilatometry indicated the occurrence of a volume increase on isothermal holding, consistent with a continuation of the martensitic transformation. On prolonged isothermal holding, a volume reduction was observed for AISI 52100, but not for AISI 1070. Copyright © 2011 by ASTM International.
Original languageEnglish
Title of host publication18th International Federation for Heat Treatment and Surface Engineering Congress : Proceedings
Number of pages13
PublisherASTM
Publication date2012
ChapterSTP153220120004
ISBN (Print)9780803175181
DOIs
Publication statusPublished - 2012
Event18th International Federation for Heat Treatment and Surface Engineering Congress - Rio de Janeiro, Brazil
Duration: 28 Jul 201030 Jul 2010
Conference number: 18

Conference

Conference18th International Federation for Heat Treatment and Surface Engineering Congress
Number18
CountryBrazil
CityRio de Janeiro
Period28/07/201030/07/2010
SeriesASTM Special Technical Publication
Volume1532

Keywords

  • Dilatometers
  • Isotherms
  • Magnetometers
  • Martensite
  • Martensitic transformations
  • Surfaces
  • Martensitic steel

Fingerprint Dive into the research topics of 'Isothermal martensite formation at sub-zero temperatures'. Together they form a unique fingerprint.

Cite this