Austenite deformation behavior and the effect of ausforming process on martensite starting temperature and ausformed martensite microstructure in medium-carbon Si-Al-rich alloy steel

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• 作者：M. Zhang ; Y.H. Wang ; C.L. Zheng ; F.C. Zhang ; T.S. Wang
• 关键词：Steel ; Thermomechanical processing ; Martensitic transformations ; Microstructure ; Hardness
• 刊名：Materials Science and Engineering: A
• 出版年：24 February, 2014
• 年：2014
• 卷：596
• 期：Complete
• 页码：9-14
• 全文大小：2891 K

文摘

Deformation behavior of austenite/supercooled austenite in a medium-carbon Si-Al-rich alloy steel is investigated on a thermomechanical simulator and an optical microscope. Effects of ausforming temperature, strain rate and strain on martensite start temperature (M_S) and ausformed martensite microstructure are studied in detail. Results show that power-law-type work hardening is caused during supercooled austenite deformation at 300 掳C; and the work hardening followed by steady-state flow is caused during the deformation at 600 and 900 掳C. The ausforming can decrease M_S, refined lath martensitic microstructure and slightly enhanced hardness. With decreasing the ausforming temperature the M_S and martensite lath thickness decrease markedly. The strain and strain rate do not have strong effects on the M_S and lath thickness. In addition, the ausforming can decrease the tetragonality of martensite and facilitate the formation of dislocation substructured martensite.