超高强钢热冲压硬化机理  

Mechanism of hot stamping hardening for ultra-high strength steel

作　　者：朱丽娟[1,2] 谷诤巍[1] 吕义[2] 徐虹[1] 

机构地区：[1]吉林大学材料科学与工程学院,长春130022 [2]长春轨道客车股份有限公司技术中心,长春130062

出　　处：《吉林大学学报（工学版）》2013年第2期376-379,共4页Journal of Jilin University:Engineering and Technology Edition

基　　金：工信部高档数控机床与基础制造装备科技重大专项项目(2009ZX04014-072-01);吉林省科技发展计划项目(20080507;20110301);长春市科技发展计划项目(10KZ01);吉林大学基本科研业务费项目(200903019)

摘　　要：以22MnB5钢为研究对象,分析了超高强钢热冲压成形过程中相变硬化机理。根据热模拟试验结果建立了加热过程奥氏体晶粒尺寸计算模型和变形抗力模型。采用有限元法对材料热冲压同时淬火冷却过程的温度场进行了分析,采用相变动力学模型分析了热成形过程中发生的相变,以及显微组织和力学性能之间的关系。结果表明:形成均匀细小板条马氏体组织的最佳工艺为900～950℃加热5min,超过30℃/s快速淬火并保压8s左右。Taking steel 22MnB5 as study object, the hardering mechanism during hot stamping of ultra- high strength steel was investigated. An austenite grain calculation model during heating process and a deformation resistance model were built based on the hot simulation test results. The transient temperature fields of steel during hot stamping and quenching were calculated by the finite element method, the phase transition of the steel during hot forming was analyzed using the phase transition kinetics model, and the relationship between the microstructures and the mechanical properties was revealed. The results showed that the optimal process to get homogeneous fine lath martensite is as follow： heating 5 min at 900 ℃-950 ℃, quenching by cooling rate over 30 ℃/s, and maintaining pressure about 8 s.

关 键 词：金属材料 热冲压 超高强钢 相变 马氏体 

分 类 号：TG111.5[金属学及工艺—物理冶金]