以CO2激光焊接304不锈钢蜂窝状冷凝板为研究对象,针对出现焊接变形问题,研究了因激光焊接功率不同导致焊缝尺寸不同对蜂窝状冷凝板焊接接头最大承载载荷、焊接残余应力与应变的影响,采用小孔法测量不同工艺条件下焊接残余应力,并提出了控制蜂窝状冷凝板焊接变形的方法。研究表明:当焊接功率为1.4、1.8kW时,两种工艺条件下纵向弯曲挠度和纵向收缩应力比与焊缝截面积之比相同为1.000∶1.328;测量所得焊接残余应力之比为1.000∶1.391,与计算所得值相近。分析发现焊缝最大承载能力与焊缝截面积有一定的关系,并提出了该新型函数关系表达式。提出了内外循环式焊接顺序,此方法能减少焊接变形的发生,又几乎不影响焊接生产效率,极大提高了蜂窝状冷凝板的生产质量。
The welding residual stress and strain of cellular ice-maker plate are considered during 304 stainless steel laser welding process. The different welding powers lead to different sizes of laser welding seam. The influence of different welding seam sizes on the maximum bearing load and deformation of cellular ice-plate is studied in laser welding with a new analysis method. And some deformation controlling methods and a new welding procedure for cellular ice-maker plate are proposed. It is showed when the welding power is 1.4 kW and 1.8 kW,the ratio of longitudinal bending deflection is about 1. 000 : 1. 328, which is equal to the ratio of longitudinal shrinkage stress respectively, and then the measured value of residual stress ratio is about 1. 000 : 1. 391, which is similar to the calculated value. The research shows that the maximum bearing load has a certain relationship with the welding seam geometry, and the new function equation between the maximum bearing load and welding seam geometry is submit during 304 stainless steel laser welding process. The cycle welding sequence of inside and outside is proposed, which not only can reduce the occurrence of the welding deformation, but also do not affect the welding efficiency, so the quality of the cellular ice-maker plate is increased greatly.