冷轧中锰钢的成形性能

 研究了两相区退火时间对中锰钢(0.1C-5Mn)的微观组织结构、力学性能及扩孔性能的影响。利用扫描电镜(SEM)和背散射电子成像技术(EBSD)对退火过程中微观组织结构的演化进行了表征；通过拉伸和扩孔试验测定了不同退火状态下中锰钢的强度、塑性和扩孔率。研究表明，中锰钢在650℃下逆转变退火获得了含有大量奥氏体相的基体为超细晶组织的奥氏体、铁素体双相钢组织，强塑积（Rm·A）达到30GPa·%以上；奥氏体体积分数随退火时间的延长而逐步增加，但过多亚稳奥氏体对钢的综合成形性能不利。

Formability of Cold Rolled Medium Manganese Steel

The intercritical annealing time effects on the microstructure, mechanical properties and hole expansion capacity of the cold rolled medium manganese steel(0.1C-5Mn) was studied. The microstructure evolution during annealing was examined by SEM and EBSD. The strength, ductility and hole expansion were measured by tensile and hole expansion test. It was found that an equiaxed ultrafine ferrite and austenite structure was developed due to the austenite-reverted transformation in the annealing process(ART-annealing) at 650℃, product of strength to ductility attained over 30GPa·%. The austenite volume fraction increased with increasing of the annealing time, but over-increased austenite fraction was detrimental to the hole expansion capacity.