回温变形温度对微合金钢显微组织的影响  

Effect of temperature on microstructure of microalloyed steel in temperature-reversion deforming process

作　　者：马江南[1] 杨才福[1] 王瑞珍[1] 

机构地区：[1]钢铁研究总院工程用钢研究所,北京100081

出　　处：《钢铁》2015年第5期63-68,共6页Iron and Steel

摘　　要：通过单道次压缩变形热模拟试验，研究微合金钢加热到两相区变形时的组织演变规律，并分析加热温度对其的影响。使用OM、SEM和EBSD分析试验钢的微观组织和取向分布。结果表明，加热后奥氏体相变在晶界上发生，740～800℃时奥氏体体积分数为20%左右，830℃时奥氏体体积分数大幅增加到50%。加热到两相区变形时，形变铁素体发生动态回复或动态再结晶，随变形温度增加，形变铁素体由动态回复向动态再结晶发展，亚晶界减少，830℃时大角度晶界比例达到91.2%，冷却后得到均匀的细晶组织，平均有效晶粒直径3.9μm。The microstructure evolution of microalloyed steel deformed in dual-phase region after heating was studied by single pass thermal-compression simulation. And the effect of heating temperature was analyzed. OM,SEM and EBSD were applied to investigate the microstructure and orientation relationship. The results show that austenite formed at prior grain boundary after heating to different temperature. The fraction of austenite at 740-800℃was about 20%,and it in-creased sharply to 50%at 830℃. Dynamic recovery and dynamic recrystallization took place in the deformed ferrite after heated to dual-phase region. With the increase of temperature,dynamic recovery of deformed ferrite transforms to dynam-ic recrystallization,which reduced the amount of subgrain. Homogeneous refined ferrite was obtained by deforming at 830℃. The fraction of high angle grain boundary reached to 91.2%,and the effective grain diameter was 3.9μm.

关 键 词：微合金钢 回温变形 两相区 铁素体动态再结晶 大角度晶界 

分 类 号：TG142.1[一般工业技术—材料科学与工程]