1.2GPa淬火—配分(Q&P)钢的成形特性研究及应用

Research andapplications of 1.2 GPa quenching and partitioning( Q&P) steel

为满足日益严格的能耗、环保和安全的要求,先进超高强钢(AHSS)的开发与应用受到愈来愈多钢厂和车厂的关注。宝钢以C-Si-Mn的成分体系为基础,采用淬火—配分(Q&P)退火工艺,成功开发出抗拉强度达1.2 GPa,断裂延伸率在15%以上,扩孔率在30%以上的新一代汽车用超高强钢。通过力学性能测试、显微组织表征以及XRD定量分析等方法对材料的强韧化机理进行了研究。结果显示,铁素体、回火板条马氏体和残余奥氏体构成的复相组织结构及残余奥氏体在变形过程中产生的TRIP效应,使得材料具有优异的综合性能,特别适合形状复杂的车身结构件和安全件的生产。

Advanced high-strength sheet steels （AHSS） have received more and more attentionfrom steel and car makers due to the increasingly severe requirements of energy cost, environmentalprotection and safety. Based on C-Si-Mn TRIP steels and quenching and partitioning （Q＆P）process, a new type of AHSS has been developed by Baosteel, exhibiting a good combination of highstrength over 1.2 GPa, adequate elongation over 15 % and hole expansion ration more than 30%. Thestrengthening and toughening mechanism of the developed steels was investigated by mechanicalproperties tests, microstructure characterization and XRD quantitative analysis. As a result, a muti-phase structure containing microstructure including ferrite,lath martensite and retained austenite andthe TRIP effect of retained austenite during deformation contribute to the excellent comprehensiveproperties, showing the application prospect of the developed steels in manufacturing of complexvehicle body and safety parts.