通过拉伸试验、金相检验和成形试验,分析了热轧卷取温度对冷轧DC01钢板显微组织和成形性能的影响。结果表明:随卷取温度由680℃升高至730℃,冷轧DC01钢板的屈服强度和抗拉强度均呈不同程度的下降趋势,下降幅度在20~30 MPa,断面收缩率A₈₀提升约2%,最高可达41.5,塑性应变比r提升约0.4,最高可达2.05,加工硬化指数n变化不大,冷轧DC01钢板的综合成形性能与罩式退火DC01钢板的相当;在730℃高温卷取条件下,DC01钢板的热轧组织和冷轧组织均为铁素体+少量珠光体,冷轧过程中再结晶阻力较小,有利于γ纤维织构的形成,使材料的塑性应变比r大幅提高,从而改善材料的冲压成形性能;在730℃高温卷取条件下,冷轧DC01钢板的相对锥杯值和胀形高度与罩式退火DC01钢板的相当,其冲杯高度达到了罩式退火DC01钢板的86%,综合成形性能良好。

By means of tensile test,metallographic examination and forming test,the effects of hot-rolled coiling temperature on microstructure and formability of cold-rolled DC01 steel plate were analyzed.The results showed that with the increase of coiling temperature from 680℃ to 730℃,the yield strength and tensile strength of cold-rolled DC01 steel plate showed a decreasing trend to varying degrees,the decreasing range was 20-30 MPa,the area shrinkage A₈₀ was increased about 2%,up to 41.5,and the plastic strain ratio r was increased about 0.4,up to 2.05,the work hardening index n did not change much.The comprehensive formability of cold-rolled DC01 steel plate was comparable to that of bell-type annealing DC01 steel plate.Under the condition of 730℃ high temperature coiling,the hot-rolled structure and cold-rolled structure of DC01 steel plate were both ferrite and a small amount of pearlite.The recrystallization resistance was small during cold rolling,which was conducive to the formation of γ fiber texture and made the plastic strain ratio increased greatly,thereby improving the stamping and forming properties of the material.Under the condition of 730℃ high temperature coiling,the relative cone value and bulging height of the cold-rolled DC01 steel plate were comparable to those of bell-type annealing DC01 steel plate,and the punching cup height of the cold-rolled DC01 steel plate reached 86% that of bell-type annealing DC01 steel plate,and the comprehensive form ability of the cold-rolled DC01 steel plate was good.