高强度钢板热冲压成形工艺的改进

Improvement of hot stamping process for high strength steel

热成形技术因结合热锻和冲压的技术优势,已经在汽车零部件制造工艺中获得了广泛的关注和应用。在热成形生产中,产品在高温下成形伴随非等温淬火过程容易出现起皱、破裂等成形质量缺陷。本文围绕高强度热成形钢板22MnB5材料相变过程、机械性能进行了相关研究,基于深冲盒试验进行热成形工艺改进优化,在热成形生产工艺过程中增加相应的转运冷却环节,使完全奥氏体化后的板料在冲压淬火前降低至优化冲压温度。实验表明:改进后的热成形工艺对冲压产品的成形性有明显改善,可有效降低和消除起皱、破裂等缺陷,材料微观马氏体转化更加细致充分,可获得抗拉强度达到1500MPa以上,硬度达到450HV以上的热成形产品,满足连续热冲压成形自动化生产过程工艺改进要求。

The transformation process and mechanical performance of high strength steel 22MnB5 have been researched in the text. The hot stamping process has been optimized based on deep drawing test. The cooling technology in transportation phase has been used in the hot stamping process in order to reduce the temperature of completely austenitized sheet into the optimal stamping temperature before quenching. The test shows that the improved hot stamping technology has improved the forming quality and reduced ＆ removed corrugation and fracture. The transformation of martensite has been more fine and sufficient with more than 1500MPa tensile strength and more than 450HV hardness. It can satisfy the improvement requirement of automatic continuous hot stamping production process.