Microstructure-mechanical property relationship and austenite stability in medium-Mn TRIP steels: The effect of austenite-reverted transformation and quenching-tempering treatments

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• 作者：Z.C. Li^a ; ^b ; H. Ding^a ; ^{dinghuaneu@163.com} ; R.D.K. Misra^b ; ^{dmisra2@utep.edu} ; Z.H. Cai^a
• 关键词：ART ; Q&T ; Mechanical properties ; Austenite stability ; TRIP effect
• 刊名：Materials Science and Engineering: A
• 出版年：2017
• 出版时间：13 January 2017
• 年：2017
• 卷：682
• 期：Complete
• 页码：211-219
• 全文大小：2421 K
• 卷排序：682

文摘

In the present study, we fundamentally explore the reasons underlying differences in mechanical properties in hot-rolled 0.2C-1.6Al-6.1Mn-Fe TRIP steels subjected to different heat treatments. Comparing with austenite reverted transformation annealing (ART) process, quenching and tempering (Q&T) process was effective in obtain excellent mechanical properties. [Q&T (UTS: 902–1235 MPa, TEL: 18–42%]; [ART (UTS: 885–945MPa, TEL: 13–28%)]. In the ART process, long time annealing led to excessive C and Mn enrichment in austenite, which rendered austenite too stable and deteriorated TRIP effect. Furthermore, long time annealing reduced dislocation density and led to low work-hardening rate. The Q&T process enabled appropriate enrichment of elements and hence desired stability for significant TRIP effect to be observed. Thus, the steel quenched from 625 °C exhibited best combination of mechanical properties (UTS: 1038 MPa, TEL: 42%, UTS×TEL: 43.6 GPa%) because of significant contribution of TRIP effect and high dislocation density in austenite.