摘要
超高强钢板热成形工艺能够实现"白车身"轻量化的同时提高其防撞安全性,能很好地解决目前汽车制造业"节能"和"安全"两大问题。本文以1.8 mm厚的BR1500HS热成形钢板为研究对象,研究了淬火工艺对其淬火组织、奥氏体晶粒尺寸和力学性能的影响。其最佳奥氏体化工艺为920℃保温5 min,淬火后的显微组织为均匀的板条马氏体,其抗拉强度高达1789 MPa,延伸率达到7.5%,强塑积为1.34×104MPa·%。根据优化的淬火工艺进行的热压淬火试验研究表明,淬火后板材的组织主要为板条马氏体,压淬件的抗拉强度高于1500 MPa,完全满足BR1500HS钢热成形件的使用要求,具有重要的工程意义。
Hot forming process of ultrahigh strength steel sheet has been regarded as one of the main feasible methods to achieve lightweight in ＂BIW＂parts and improve its collision safety performance,which is a good solution to the problems of energy saving and good safety. In this paper,the effects of austenitizing process parameters on microstructure,the austenite grain size and mechanical properties of BR1500 HS steel with 1. 8 mm thick is investigated. It is found that the optimum austenitizing process is heated at 920℃ and 5 min,through which the microstructure is composed by uniform lath martensite after quenching.And its tensile strength is up to 1789 MPa,elongation rate reaches 7. 5%,strong plastic product achieves1. 34 × 10^4MPa·%. Test of hot pressure quenching according to the optimized quenching process shows that the structure of plates after quenching is mainly composed of lath martensite,and the tensile strength of pressure quemchig part is higher than 1500 MPa,which meet the operating requirements of hot forming part of BR1500 HS and has important engineering significance.
出处
《热处理技术与装备》
2015年第5期41-46,共6页
Heat Treatment Technology and Equipment
基金
国家自然科学基金资助项目(51475280)
