Influence of Annealing Temperature on Microstructures and Tensile Properties of Hot-rolled 7Mn Steel
Influences of intercritical annealing (IA) temperature on the microstructures and the tensile properties of a newly designed medium Mn steel,Fe-7 wt % Mn-0.3 wt % C-2 wt % Al,have been studied after hot rolling and IA in this paper.The final microstructure is composed of austenite,ferrite and/or martensite lamellar laths,whose thickness shows weak dependence on the annealing temperature.With the increasing temperature,the calculated Mn and C equilibrium contents increase but the Al content decrease,leading to the decrease of Ms temperature.Since austenite stability is mainly governed by chemical compositions in the present case,the lower IA temperature results in more stable austenite grains retained.During tensile tests,about one third of the retained austenite (RA) grains in the specimen annealed at 680℃ have transformed to marteniste while almost all of RA have transformed quickly in the one annealed at 720℃.Both lead to reduced ductility in comparison with the specimen annealed at 700℃,which exhibits superior plasticity with the optimal product of UTS and TE,i.e.46GPa·%.
medium Mn steel TRIP effect austenite stability
YANG Feng LUO Haiwen DONG Han
Central Iron & Steel Research Institute, Beijing 100081, China School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Be
国际会议
成都
英文
282-285
2016-11-16（万方平台首次上网日期，不代表论文的发表时间）