预成形件对超高强钢板热冲压减薄率的影响

为了降低超高强钢板在热冲压过程中的减薄率,以车轮侧盖为研究对象,设计了4种预成形件结构方案,通过有限元模拟分析预成形件形状、尺寸对减薄率的影响,基于模拟结果,进行了预成形件热冲压实验。结果表明:热冲压件的显微组织为板条马氏体,显微硬度达到460 HV以上;零件球窝处材料减薄率最大,预成形有利于降低材料减薄率;预成形件储料面积越大,热冲压件材料减薄率越小;预成形件为深度为22.8 mm的圆拱形储料结构且切角时,材料减薄率最小,为11.67%,壁厚均匀性较好。实际热冲压实验结果和数值模拟结果基本一致。

Influence of preformed parts on the thinning rate of hot stamping for ultra high strength steel sheet

In order to reduce the thinning rate of ultra high strength steel sheet in hot stamping process, for wheel side cover, four kinds of preformed part structure schemes were designed, and the influences of shape and size of preformed parts on the thinning rate were analyzed by the FEM simulation.Then, the hot stamping experiment was carried out based on the simulation results.The forming results indicate that the microstructure of hot stamping parts consists of lath martensite, and the micro.hardness reaches above 460 HV.The maximum material thinning rate is on the ball pocket, and the pre.forming helps to reducing the material thinning rate.The larger the material storage area of preformed parts is, the smaller the material thinning rate of hot stamping parts is.When the preformed part is a circular arch with a depth of 22.8 mm and cutting corners, the material thinning rate is the minimum as 11.67%, and the wall thickness uniformity is better.The experimental results are approximately accordant with the numerical simulation results.