变形温度对Fe-11Mn-4Al-0.2C钢奥氏体稳定性的影响

以锰元素质量分数为11%的冷轧中锰钢为研究对象,通过分析在不同变形温度下实验钢的显微组织和力学性能的变化规律,研究变形温度对奥氏体稳定性的影响,最终确定Mσs的温度为20~25℃.结果表明,随着拉伸温度的升高,实验钢的奥氏体稳定性逐渐增高,应变硬化能力逐渐降低.在Mσs点附近进行拉伸时,实验钢中应力诱发马氏体相变和应变诱发马氏体相变两种机制并存,TRIP效应对实验钢强度和伸长率的贡献最大,因此综合力学性能最好.通过理论模型计算可得实验钢的奥氏体平均晶粒尺寸为0.70~0.71μm.

Effect of Deformation Temperature on Stability of Austenite in Fe-11Mn-4Al-0.2C Steel

The cold-rolled 11 wt% Mn steel was investigated in this work. The microstructure and mechanical properties of the samples tensioned at different temperatures were studied to investigate the effect of deformation temperature on the stability of austenite in the steel. The temperature of M^σ_s was finally determined in the range of 20~25℃. The results showed that the stability of austenite increased with increase of the temperature during straining，leading to decrease of the strain hardening ability. When the samples were tensioned at the temperature around M^σ_s， both of the stress-induced and strain-induced martensitic transformation were found. Therefore， the best combination of strength and ductility was obtained， which mainly contributed by TRIP effect. The average grain size in the austenite was calculated in the range of 0.70~0.71μm by a theoretical model.