超声冲击对金属焊接接头组织及性能影响的研究现状

Study Status of Ultrasound Impacting to Microstructure and Properties of Metal Welded Joint

用超声冲击法处理金属焊接接头后,可获得具有一定厚度的塑性变形层,晶粒明显得到细化,某些晶粒尺寸甚至可达纳米量级。超声冲击还能提高金属焊接接头的显微硬度、抗拉强度和疲劳强度等性能,此外超声冲击可引入对提高疲劳强度有利的残余压应力及改善焊趾处的应力等。超声冲击法在金属焊接接头的焊后强化处理及相关领域方面的应用愈来愈广泛,具有很大的发展潜力。

Toe is the main weak part of welded joint,so the fatigue fracture often begin from the toe.It can be known from many reports that after treated by ultrasound impacting,the plastical deforming layer with a certain thickness can be obtained on the surface of the welded joint,and the properties can be improved,for example,the microhardness,tensile strength and fatigue strength can be also improved.Besides,ultrasound impacting can bring residual pressure on the surface,and reduce the stress concentration.Ultrasound impacting is more and more widely used in the area of strengthening the metal welded joints and related areas,which is with big developing protential.