先进高强钢断裂性能研究  

Study on the fracture performance of AHSS

作　　者：祝洪川[1] 孙宜强[1] 吴青松[1] 

机构地区：[1]武汉钢铁集团公司研究院,湖北武汉430080

出　　处：《锻压技术》2015年第12期115-119,共5页Forging & Stamping Technology

基　　金：湖北省重大科技创新计划项目(2013AAB008)

摘　　要：在铁素体-马氏体双相钢的成形过程中,因材料边裂而导致的冲废和返修是其使用的一个主要问题。本文以双相钢DP780冲压某汽车零件出现开裂为例,比较了常规拉伸和切边拉伸(试样落料后不打磨边部)的力学性能,观察了断口的组织和形貌。试验结果表明切边质量较差的试样其伸长率要比切边质量好的试样低10%左右,Mn的偏析使得马氏体组织和Mn S夹杂沿轧向呈带状分布造成了横向切边试样的伸长率要比纵向切边试样低3%左右。裂纹在双相钢中的扩展沿着马氏体-铁素体晶界或穿过马氏体,细小的呈簇状分布的马氏体颗粒增加了双相钢的裂纹敏感性,降低了材料的抗断裂性能。In the forming process of ferrite-martensite DP-steel, it is a key problem that the edge cracking resulting in repair or failure. For an edge cracking in stamping an automobile part with DP780, the material mechanical property was compared with the standard tensile test and the cutting edge tensile test, and the crack morphology and the microstructure were also investigated. The experiment results show that the elongation of bad cut specimen is nearly 10% less than that of the good cut specimen, and the elongation of transverse cut speci- men is 3% less than that of the longitudinal cut specimen caused by Mn segregation phase which making the martensite and MnS inclusion form a zonal distribution along the longitudinal direction. The crack in DP-steel evolves along the ferrite-martensite interface or through martensite, and the tiny martensite with cluster-type distribution increases crack sensitivity of DP-steel, while decreases its fracture performance.

关 键 词：双相钢 冲压成形 微观组织 断裂性能 

分 类 号：U466[机械工程—车辆工程] TG142.12[交通运输工程—载运工具运用工程]