疲劳加载下A7N01铝合金焊接残余应力演变研究

Residual stress evolution of welding joint of A7N01 aluminum alloy under fatigue load

采用超声法研究A7N01铝合金焊接接头的残余应力分布及其在疲劳加载过程中的变化。A7N01铝合金焊接接头的残余应力峰值出现在焊缝区域,且为拉应力,母材区的残余应力为压应力。在低应力水平下,焊接接头焊缝区的残余应力值先增大后减小,应力的释放率与外加应力以及自身残余应力水平有关。外加载荷越大,焊接接头的残余应力释放越多,焊缝区的残余应力峰值降低,但100 MPa以下的应力不能释放母材区的残余应力。

The dist,ibntion of residual stress of A7N01 aluminum alloy welding joint anti the evolution of residual stress under fatigue load were tested through uhrasound method. The residual stress peak value was loeated in the welding seam which was tensile stress, and the base metal showed compress residual stress. Under tatigue loading of low level ,the residual stress of welding seam increased first and then decreased,the released rate of residual stress was related to the loading stress and the residual stress of the welding seam itseff. The greater the load,the more residual stress released.which led to the decrease of residual stress peak value of welding seam. However,the residual stress of base metal could not be released trader the 100 MPa fatigue load.