不同强度级别的汽车大梁钢成形性能分析

Analysis of Forming Performance of Automotive Beam Steel with Different Strength Levels

对比研究了三种不同强度级别的汽车大梁钢的成形极限曲线,并结合力学性能、微观组织对其进行了综合分析。研究发现,随着汽车大梁钢强度级别的升高,其断后伸长率和应变硬化指数下降;钢的微观组织以铁素体为主,并带有少量珠光体,其中铁素体细小且部分有团簇聚集的特征;从成形极限曲线看出,在单向拉伸状态和双向胀形状态下,主次应变值随大梁钢级别的升高而降低,主应变极值点(FLD_(0))处的应变值也呈现相同的变化趋势。

The forming limit curves of three different strength grades of automotive beam steels were compared and studied,and combined with mechanical properties and microstructure,it was analyzed synthetically.The results show that with the increase of the strength grade,the elongation after breaking and strain hardening index of automobile beam steel decrease.The microstructure of the steels is mainly ferrite with a small amount of pearlite,in which ferrite is small and some of them have cluster aggregation characteristics.From the forming limit curve,it can be seen that the primary and secondary strain values decrease with the increase of the beam steel grade,and the main strain values at the extreme point(FLD_(0))of the main strain show the same trend.