Effects of thermomechanical processing on microstructure and shear properties of 22SiMnCrMoB trip-aided martensitic steel

Tomohiko Hojo, Junya Kobayashi, Takuya Kochi, Koh Ichi Sugimoto

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The effects of the working temperature, working reduction ratio, and post cooling rate on the microstructural change, retained austenite characteristics, and shear properties of 22SiMnCrMoB transformation-induced plasticity (TRIP)-aided martensitic (TM) steel were investigated. The slow cooling rate at 1 °C/s after warm working at 650 °C with a reduction ratio of 40-60% refined the grain size to 1-2 μrn and considerably increased the volume fraction of retained austenite, although the matrix structure changed to a granular bainitic ferrite structure, with the decreased volume fractions of the martensite-austenite constituent (MA)-like phase and carbide. On the other hand, the rapid cooling at 20 °C/s performed after the same warm working resulted in a refined lath martensite structure matrix and a large amount of the MA-like phase, although the volume fraction of retained austenite was small because of the precipitation of a large amount of carbides at the wide lath martensite. High shear strength, large shear elongation, and a superior combination of shear strength and shear ductility were attained by performing a rapid cooling after the warm working. AISTech 2015 Proceedings

Original languageEnglish
Title of host publicationAISTech 2015 - Proceedings of the Iron and Steel Technology Conference and ICSTI 2015
PublisherAssociation for Iron and Steel Technology, AISTECH
Pages3426-3434
Number of pages9
Volume3
ISBN (Electronic)9781935117476
Publication statusPublished - 2015
Externally publishedYes
EventAISTech 2015 Iron and Steel Technology Conference and 7th International Conference on the Science and Technology of Ironmaking, ICSTI 2015 - Cleveland, United States
Duration: 2015 May 42015 May 7

Other

OtherAISTech 2015 Iron and Steel Technology Conference and 7th International Conference on the Science and Technology of Ironmaking, ICSTI 2015
CountryUnited States
CityCleveland
Period15/5/415/5/7

Keywords

  • Retained austenite
  • TRIP-aided martensitic steel
  • Ultra fine grain
  • Warm working

ASJC Scopus subject areas

  • Industrial and Manufacturing Engineering

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