热处理工艺对冷轧热镀锌双相钢组织与性能的影响

在实验室试制了热镀锌冷轧DP590双相钢,分析了临界区退火温度对双相钢组织性能的影响,并将同种成分的实验室试制双相钢与工业生产双相钢的组织性能作对比,结果表明:热镀锌双相钢在镀锌段易出现贝氏体组织,且随临界区温度的上升,贝氏体组织含量增多,双相钢的强度上升,而塑性下降;工业试制双相钢,贝氏体和马氏体交互附着在铁素体晶界上,它们的体积分数约占29%,抗拉强度为610MPa,伸长率为31.5%,各项性能符合要求。研究得出,通过控制第二相(马氏体+贝氏体)体积分数和分布形态,能够充分改善热镀锌双相钢的力学性能。

Effects of Heat Treatment Process on Microstructure and Properties of Hot-Dip Galvanized Dual-Phase Steel

The hot-dip galvanized 590 Mpa grade cold rolling dual phase steels were trial-produced in laboratory.The effects of critical annealing temperature on microstructures and properties were investigated.Microstructures and properties were compared and analyzed between laboratory and industrial products with the same chemical compositions.The results show that the absence of bainite is usual in hot-dip progress;both the bainite content and the ultimate tensile strength increase and the elongation decrease with the increasing of critical annealing temperature.The bainite and martensite volume fraction of industrial products is 29%.The ultimate tensile strength and elongation is 610 MPa and 31.5%,respectively,and the performance meets the requirement.The research indicate that if the volume fraction and distribution patters of the second phase(bainite+ martensite) can be controlled,the mechanical properties of hot-dip galvanized dual phase will be fully improved.