汽车用变强度钢的工艺和性能研究

Research on process and mechanical properties of automotive variable strength steel

从汽车的发展趋势出发,结合B柱的设计要求,分析了变强度钢(VASS)在轿车的应用前景,研究了变强度钢的生产工艺和力学性能特征。所设计的变强度钢高强度部分、低强度部分分别采用全奥氏体区淬火、临界区淬火。根据生产实际情况,得到了Ac3及与其相关的碳当量的计算公式。提供了含马氏体汽车用高强度钢的硬度和抗拉强度换算关系,方程的相关系数较高。在单位吸收能的计算中,提供了积分法和像素法两种方法,其中像素法可广泛用于计算复杂封闭曲线面积的工程问题。所设计的变强度钢高强度部分抗拉强度在800 MPa以上,低强度部分的单位吸收能接近高强度部分的1.5倍。

Based on the development trend of Automobile and design requirement of B pillar,the application prospect of variable strength steehor called VASS.was analyzed.the process and mechanical properties of VASS was researched.The higher strength area and lower strength area of VASS was introduced with full auslenite quenching and intercritical quenching treatment respectively.According to the industrialized process characteristics,the relationship between Acs temperature and related carbon equivalent was drew out.A high correlation coefficient function of hardness and tensile strength calculation of martensite contained high strength automotive steel was provided.There are two different solutions for unit absorbed energy calculation,one of them is integration method.and the other is pixel method.The pixel method can be used for calculate complex close curve area in engineering field.Fhe tensile strength of higher strength area of VASS designed is higher than 800 MPa.The unit absorbed energy of lower strength area is about 1.5 times of liigher strength area.