摘要
针对不锈钢薄板熔透和非熔透型激光搭接焊,以80和10 mm作为考虑和不考虑残余应力影响的试样宽度,对两种宽度试样进行一系列的拉伸和疲劳试验,获得了焊接残余应力对薄板搭接接头力学性能的影响规律,进行了有关机理分析.结果表明,搭接焊缝正、背面存有较大的纵向残余拉应力和较小的横向残余压应力;残余应力的存在会降低搭接焊接头的拉剪强度和疲劳强度.改变激光入射角和搭接间隙,残余应力对拉剪强度的降低程度随之改变:增大入射角至20°,熔透型接头降低程度达到0°时的7倍,而非熔透型为10倍;搭接间隙在一定范围内增大时,残余应力对拉剪强度的降低程度也随之加剧.
Aimed at the penetrating and non-penetrating laser overlap welding of stainless steel sheet,80 mm and 10 mm were recognized as the widths with or without considering the effect of residual stress respectively. Then,a series of tensileshear and fatigue tests of specimens with two widths were carried out. Finally,the effect of welding residual stress on the mechanical properties of the welded joint was obtained,and the analysis of this effect was taken. The results showed that there were larger longitudinal tensile stress and smaller transverse residual compressive stress on the front and back of the overlap joints; the existence of residual stress not only reduced the tensile-shear strength of the joint,but also reduced the fatigue strength. The degree of reduction changed with the irradiation angle and overlap gap changed. When the irradiation angle increased to 20°,for penetrating welding,the degree of reduction of tensile-shear strength,which was caused by residual stress,was up to 7 times the original,and for non-penetrating welding it was up to 10 times. Moreover,when the overlap gap increased within a certain range, the degree of reduction of tensile-shear strength caused by residual stress increased.
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2017年第10期112-116,共5页
Transactions of The China Welding Institution
关键词
激光搭接焊
残余应力
拉剪强度
疲劳强度
laser overlap welding
residual stress
tensile-shear strength
fatigue strength
