喷砂处理对铝合金车体焊接残余应力分布规律的影响  

Influence of the sandblasting on the welding residual stress of the aluminum alloy train-body

作　　者：马纪军[1] 苟国庆[2] 陈辉[2] 吉华[2] 马传平[2] 

机构地区：[1]唐山轨道客车有限责任公司,河北唐山063035 [2]西南交通大学材料科学与工程学院,四川成都610031

出　　处：《电焊机》2011年第11期26-29,共4页Electric Welding Machine

基　　金：国家科技支撑计划资助项目(2009BAG12A04-B02)

摘　　要：选取某型号的铝合金焊接车体,采用喷砂工艺对铝合金车体进行了表面处理。采用X射线衍射法残余应力测试技术,对铝合金车体的重点部位——车顶及侧墙区域喷砂前后的焊接残余应力进行了测试研究。结果表明,喷砂前测试的焊缝区域纵向残余应力呈现拉应力状态,而横向残余应力没有规律性分布,并且在两个应力方向应力梯度比较大。经过喷砂处理后,焊缝区域的纵向和横向应力状态均呈现为压应力状态,而且应力跨度减小,分布更加均匀,残余压应力的存在可以有效抑制表面裂纹的萌生,提高裂纹扩展门槛值ΔKth,从而提高了列车的疲劳强度和使用寿命。In this paper,the aluminium alloy body of aluminum alloy train-body has been treated using sand blasting.The welding residual stress of the roof and side wall areas of the body was measured,both initial stress and that ＇after blasting,using X-ray Diffraction technology（XRD）.The result showed that the longitudinal residual stress of the both tested areas was tensile, but the transverse position was not regular,and the stress gradient of both position was distinctly large.However,after blasting,the residual stress of the both position presented compressive,and the span of the residual stress decreased,and the distribution was more even.The residual stress can inhibited the initiation of the cracks,heightened the expanded threshold value △Kth,which can improve the fatigue properties of the train-body.

关 键 词：X射线衍射法 铝合金 残余应力 喷砂 

分 类 号：TG404[金属学及工艺—焊接]