610L汽车大梁钢成型开裂分析

ANALYSIS OF CRACKING IN THE FORMING PROCESS OF 610L AUTOMOBILE BEAM STEEL

成型开裂是汽车大梁钢在应用中失效的主要形式,而车辆桥壳的成型形状相对比较复杂,在冲压过程中更容易出现开裂问题。针对国内某钢厂生产的610L汽车大梁钢在下料及加工车辆桥壳过程中产生的分层开裂问题,分别从客户的两个基地取样,且两地样品均有分层开裂现象,利用直读光谱仪、拉伸试验机、光学显微镜(OM)、扫描电子显微镜(SEM)以及能谱仪等检测仪器,对板料样品的化学成分、力学性能、显微组织和夹杂物进行检测和分析。结果表明,由于板料中存在严重的MnS中心偏析,且偏析带内含有大量的TiN析出物,破坏了基体组织的均匀性和连续性,进而影响其成型的塑韧性,导致在加工车辆桥壳过程中出现分层开裂问题,并阐述炼钢以及轧钢工艺中可以有效控制MnS夹杂物和TiN析出物的措施,为实际生产提供理论支撑。

Cracking during forming process is the main form of failure in the application of automotive beam steel,and the forming shape of vehicle axle shells is relatively complex,making it more prone to cracking during the stamping process.In view of the delamination and cracking problem of 610L automobile girder steel produced by a domestic steel factory in the process of processing vehicle axle housing,samples were taken from two customer bases,and the samples in both places had delamination and cracking phenomenon.The chemical composition,mechanical properties detection and analysis of microstructure and inclusions.The results indicate that due to severe central segregation in the sheet metal and the presence of a large amount of precipitates and inclusions in the segregation zone,the uniformity and continuity of the microstructure are disrupted,which in turn affects the plastic toughness of its formation,leading to delamination cracking during the processing of vehicle bridge shells.Measures that can effectively control inclusions in steel making processes are elaborated,providing theoretical support for practical production.