超声冲击处理改善22SiMn2TiB钢焊接接头的疲劳性能  

Fatigue Performance Improvement of 22SiMn2TiB Steel Welded Joint by Ultrasonic Impact Treatment

作　　者：叶雄林[1] 朱有利[1] 马丽丽[1] 李占明[1] 

机构地区：[1]装甲兵工程学院装备再制造工程系,北京100072

出　　处：《机械工程学报》2009年第8期283-286,共4页Journal of Mechanical Engineering

基　　金：北京市自然科学基金资助项目(3093027)

摘　　要：研究超声冲击处理(Ultrasonic impact treatment,UIT)对22SiMn2TiB钢焊接头疲劳性能的作用。疲劳试验用焊态和UIT样品,X射线衍射应力测定仪测试焊态和UIT样品残余应力分布,扫描电镜(Scanning eletron microscopy,SEM)对疲劳样品断口形貌进行分析,确定了裂纹形核机制。结果表明超声冲击处理可以提高22SiMn2TiB钢焊接头疲劳寿命。对于焊接接头,UIT改变了裂纹形核机制,从焊趾处的表面形核演变为次表面形核。UIT处理消除了焊趾处微缺陷,并引入残余压应力,限制焊趾表面起裂,导致焊接接头更长的疲劳寿命。The effects of ultrasonic impact treatment （UIT） on fatigue performance of 22SiMn2TiB steel welded joint are investigated. Fatigue tests are carried out by using as-welded and UIT treated specimens. X-Ray diffraction stress measurements are performed on the distributions of residual stress of the specimens. With the aid of scanning electron microscopy （SEM）, fractographic analyses are carried out on the fatigue specimens to determine the crack nucleating mechanism. The results indicate that the UIT can improve the fatigue life of 22SiMn2TiB steel welded joint. For the welded joint, the UIT changes the crack nucleating mechanism from surface cracking at welded toe to subsurface. As micro-defects are eliminated and residual compressive stresses are introduced by UIT at the welded toe, the surface cracking is constrained, which results in a much longer fatigue life of the welded joint.

关 键 词：超声冲击处理 焊趾 疲劳性能 残余应力 

分 类 号：TG405[金属学及工艺—焊接]