冷轧压下率对TRIP钢组织性能的影响

Effect of cold rolling reduction rate on microstructure and mechanical properties of TRIP steel

冷轧压下率对TRIP钢成品带钢力学性能和成形性能有重要的影响。以TRIP600钢为例,采用金相显微镜和拉伸试验机等检验设备,研究了不同冷轧压下率(50%、55%、60%和65%)对其组织和性能的影响。结果表明,随着冷轧压下率的增加,成品带钢组织中铁素体晶粒尺寸减小,铁素体体积分数减少,贝氏体+马氏体+残余奥氏体体积分数增加;其屈服强度和抗拉强度随着压下率的增加而增大,塑性指标则呈现先增大后减小的趋势;当压下率为60%时,成品带钢各项性能指标最佳,其强塑积为21.3 GPa·%,此时组织中残余奥氏体体积分数与其C质量分数的乘积较高,与TRIP效应提高带钢强塑积的理论一致。

The cold rolling reduction rate has an important influence on the mechanical properties and forming properties of the finishing strip.Taking TRIP600 steel as an example,using metallographic microscope,tensile testing machine and other inspection equipment,the effect of different cold rolling reductions rates(50%,55%,60%and 65%)on its structure and properties was studied.The results show that with the increase of cold rolling reduction rate,the ferrite grain size in the structure of finishing strip decrease,the volume fraction of ferrite decrease,and the volume fraction of bainite+martensite+residual austenite increase.The yield strength and tensile strength of finishing strip increase with the increase of the reduction,while the plastic index shows a trend of increasing first and then decreasing.When the reduction rate is 60%,the performance indicators of the strip are the best,its strength plasticity product is 21.3 GPa·%.At this time,the product of the volume fraction of retained austenite in the structure and its C mass fraction is higher,which is consistent with the theory of TRIP effect to increase the strength plastic product of the strip.