Effect of initial austenite grain size on microstructure development and mechanical properties in a medium-carbon steel treated with one-step quenching and partitioning

Toshihiro Tsuchiyama, Yoshinori Amano, Shohei Uranaka, Takuro Masumura

Research output: Contribution to journalArticlepeer-review

Abstract

Fe-0.4C-1.2Si-0.8Mn (mass%) alloys austenitized at different temperatures, ranging from 1 103 to 1 473 K, were subjected to interrupted quenching (IQ) at 473 K and then maintained at that temperature to induce the partitioning of carbon from martensite to austenite (one-step quenching and partitioning (Q&P) process). The initial austenite grain size before the IQ was varied from 20 to 573 m. As the initial austenite grain size becomes finer, the enrichment of carbon in the untransformed austenite during the partitioning treatment is enhanced, which leads to a greater increase in the volume fraction of retained austenite. The reasons for the increased carbon enrichment were explained by the effective carbon partitioning as well as the promoted bainitic transformation, which were both caused by the increase in the area of the martensite/austenite interface. Tensile tests of the specimens with different initial austenite grain sizes revealed that the mechanical properties of the one-step Q&P specimens improved in both strength and elongation by the refinement of the initial austenite grains.

Original languageEnglish
Pages (from-to)537-545
Number of pages9
Journalisij international
Volume61
Issue number2
DOIs
Publication statusPublished - Feb 15 2021

All Science Journal Classification (ASJC) codes

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Effect of initial austenite grain size on microstructure development and mechanical properties in a medium-carbon steel treated with one-step quenching and partitioning'. Together they form a unique fingerprint.

Cite this