薄壁换热管-管板接头自动焊接工艺研究

Study on Automatic Welding Technology of Thin Wall Heat Exchange Tube-Tubesheet Joint

本文主要对φ19mm×l．0mm薄壁不锈钢换热管与管板接头焊接进行难点分析和相关工艺试验，确立了采用可编程管板自动焊机脉冲氩弧焊方法实施高效稳定焊接的工艺参数。对不同管子伸出长度和钨极角度进行焊接试验对比，确定了管伸出长度保持在1．0～1．5mm、钨极角度保持在20°～22°为最佳参数。采用两层施焊工艺，第一层不加丝打底焊保证根部熔透，第二层加丝盖面焊保证焊角尺寸和接头强度，是实现管子与管板强度焊接的最优工艺。采用分段设置焊接参数，可保证5FG接头在不同焊接位置都能得到理想的焊缝成形和焊接质量。

This paper mainly analyzed the difficulties and related process tests of the welding of the diameter of the stainless steel tube and the pipe plate joint of the diameter 19mm×1.0mm thin wall. The process parameters of high efficiency and stability welding were established by using the pulse argon are welding method of the programmable tube plate automatic welding machine. The optimum parameters of the pipe elongation at 1 ~ 1.5mm and the tungsten pole angle at 20° ~ 22°degrees were determined by the comparison of the length of the pipe and the tungsten electrode. Using the two layer welding process, the first layer without wire bottom welding ensured the penetration of the root, and the second layer welding to ensure the weld angle size and joint strength was the best process to realize the strength welding of tube and tube plate. Using segmented welding parameters could ensure that 5FG joints could get ideal weld shape and welding quality in different welding positions.