摘要
研究了DP980-GMW2和Q&P980-GMW2钢板拉剪型焊点的金相组织、硬度分布和疲劳性能;采用扫描电镜分析了疲劳断口的形貌特征。结果表明:DP980-GMW2和Q&P980-GMW2钢板拉剪焊点的疲劳极限分别为1000和1200 N;焊核区都形成粗大的马氏体;由于马氏体回火,造成DP980和Q&P980钢板在热影响区都出现软化现象;疲劳断口由裂纹源、扩展区、瞬断区组成。
The microstructure characterization, microhardness and fatigue test of spot welded DP980-GMW2 and Q＆P980-GMW2 were performed by using tensile-shear. The fracture morphology was explored by SEM. The results show that the fatigue limit loads of tensile shear of DP980-GMW2 and Q＆P980-GMW2 are 1000 and 1200 N, respectively. The microstructure of FZ consists of large martensite. There are sorting regions in the HAZ due to the martensite tempering of DP980 and Q＆P980. The fatigue fracture consists of crack initiation area, crack propagation area and final fracture area.
出处
《热加工工艺》
CSCD
北大核心
2016年第5期28-32,共5页
Hot Working Technology
基金
国家自然基金重点项目(51331007)
关键词
点焊
显微组织
硬度
疲劳极限
断口形貌
resistance welding
microstructure
hardness
fatigue limit loads
fracture morphology
