热冲压成形22MnB5钢板的组织和性能  

Microstructure and properties of hot stamping 22MnB5 steel

作　　者：姜超[1] 单忠德[1] 庄百亮[1] 戎文娟[1] 张密兰[1] 

机构地区：[1]机械科学研究总院先进制造技术研究中心,先进成形技术与装备国家重点试验室,北京100083

出　　处：《材料热处理学报》2012年第3期78-81,共4页Transactions of Materials and Heat Treatment

基　　金：国家国际科技合作项目(2011DFA50810);国家04科技重大专项(2011ZX04016-051)

摘　　要：采用扫描及透射电镜观察和力学性能实验研究了22MnB5钢板热冲压成形件的组织形貌和力学性能。结果表明,加热温度930℃,保温4.5 min,初始成形温度850℃,冲压速度75 mm/s条件下,22MnB5钢板热冲压成形完成完全马氏体转变,得到均匀板条马氏体组织,组织内产生高密度位错,强度大幅提升,抗拉强度达到1550 MPa。形变有助于动态再结晶并获得更为细小的马氏体组织,促进细晶强化。硼元素在晶界发生偏聚,延长奥氏体转变孕育期,提高了22MnB5钢的淬透性,同时引起点阵畸变,促进相变强化。Microstructure and properties of 22MnB5 steel after hot stamping were studied by means of mechanical property test and microstructure analysis through SEM and TEM.The results show that the microstructure of lath martensite with high-density dislocations is obtained for the steel after hot stamping,and its mechanical properties of the steel are significantly increased.Deformation help dynamic recrystallization and getting more tiny martensite organization to promote fine-grain strengthening.On one hand,boron segregation at grain boundaries reduces distortional energy and extends the austenitic change incubation period so as to improve the hardenability of 22MnB5 steel,on the other hand,boron segregation causes lattice distortion.Both of the reasons promote transformation strengthening of the steel.

关 键 词：22MnB5钢 热成形 相变强化 

分 类 号：TG113[金属学及工艺—物理冶金]