|About this Abstract
||2020 TMS Annual Meeting & Exhibition
||Advanced High Strength Steels IV
||Effects of Prior Austenite Grain Size on Microstructure of Bainite and Retained Austenite in TRIP Steel
||Miku Watanabe, Goro Miyamoto, Tadashi Furuhara
|On-Site Speaker (Planned)
In TRIP steel austenite is stabilized by carbon enrichment during bainitic transformation. The stability depends on its size and morphology, which should be affected by prior austenite grain size. Thus, the purpose of this study is to reveal the effects of prior austenite grain size on microstructure and mechanical property in TRIP steel. Fe-2Mn-1.5Si-0.4C (mass%) alloy was used. Large (348 microns) and Small (12.5 microns) austenite grain sizes were obtained through austenitization at 1150 degC and 830 degC, respectively. Following to austenitization, samples were isothermally transformed at 400 degC for various reaction time. Quantitative analysis based on SEM images reveals that large-grained specimen contains a high density of film-like austenite and a few coarse blocky austenite while untransformed austenite is mostly fine blocky austenite in the small-grained specimen. FE-EPMA measurement clarifies that carbon content in austenite increases with decreasing austenite grain size, which further stabilizes fine untransformed austenite.
||Planned: Supplemental Proceedings volume