回填式搅拌摩擦点焊结构的最佳焊点间距研究

Research on Optimizing Welding Spot Spacing for Refill Friction Stir Spot Welding Structure

采用XRD技术测量了单焊点接头与多焊点接头的残余应力,并分析了焊点间距对接头残余应力分布的影响规律。结果表明:单焊点接头焊点区域的纵向和横向残余应力均为拉应力,且随距焊点中心距离的增加而减小。多焊点接头中间焊点的纵向残余应力分布与单焊点相似但数值相应降低,其中沿x方向各点的纵向残余应力降低幅度较大。中间焊点的最大纵向残余应力随焊点间距增大呈现先降低后增加的趋势。焊点间距为20 mm的接头最大纵向残余应力值最小,为47 MPa。

The residual stress of single-spot joint and multi-spot joint was measured by XRD technology, and the influence of welding spot spacing on residual stress distribution of joint was analyzed. The results show that the longitudinal and the transverse residual stress of welding spot are tensile stress and decrease with distance from the center of welding spot on the single-spot joint increasing. The longitudinal residual stress distribution of the center welding spot on the multi-spots joint is similar to that of single-spot joint, but the values are relatively lower. The reduction of longitudinal residual stress of every point along x direction is larger. The maximum longitudinal residual stress of the middle welding spot decreases first and then increases with the increase of welding spot spacing. The maximum longitudinal residual stress at the joint is smallest,which is 47 MPa, when the welding spot spacing is 20 mm.