汽车用热轧双相钢的组织性能测试及研究
Test and Research on Microstructure and Properties of Hot Rolled Dual Phase Steel for Automobile

基于汽车轻量化原则，通过控轧控冷工艺技术得到了强韧性较好的DP580和DP600热轧双相钢，研究了等温时间对其组织与性能的影响。研究表明：随着等温时间增加，钢中铁素体的尺寸和体积分数均增加，抗拉强度由616 MPa降低至586 MPa，伸长率较高在30%左右，屈强比较低小于0.6，n值较高在0.18~0.20。同时考虑到产线上长时间的等温会降低生产效率，故试验钢合适的等温时间为7 s左右。
Based on the principle of vehicle lightweight, DP580 and DP600 hot rolled dual phase steels with good strength and toughness were obtained by controlled rolling and controlled cooling technology, and then effect of isothermal time on microstructure and mechanical properties of the tested steel was studied. The results show that with the isothermal time increases, the size and volume fraction of ferrite increase, the tensile strength is reduced from 616 MPa to 586 MPa, the elongation is about 30%, the yield ratio is lower than 0.6, and the n value is 0.18~0.20. Considering that the production efficiency will be reduced if the production line is isothermal for a long time, the appropriate isothermal time for the test steel is about 7 s.