316L钢内衬复合管焊接接头的耐点蚀性能

Pitting Corrosion Resistance of Welded Joints of 316L Lined Composite Pipe

采用FeCl3溶液点蚀试验和点蚀电位测量,结合化学成分、显微组织分析,腐蚀形貌观察和失重试验,对采用三种工艺焊接的316L钢内衬复合管焊接接头的焊缝和热影响区的耐点蚀性能进行了研究。结果表明:用三种焊接工艺焊接的接头耐点蚀性能依次为:端部堆焊+625合金焊丝+钨极氩气保护焊工艺>端部封焊+625合金焊丝+钨极氩气保护焊工艺>端部封焊+药芯焊丝对焊工艺;采用端部堆焊+625合金焊丝+钨极氩气保护焊接工艺焊接的焊缝及热影响区耐点蚀性能最好。

Pitting corrosion tests in FeC13 solution and pitting potential measurements, chemical composition analysis, microstructure analysis, corrosion morphology observation and weight loss testing were used to study the pitting corrosion resistance of welding seams and heat affected zones in the welded joints of 316L lined composite pipes using three kinds of welding process. The results show that the order of pitting corrosion resistance of the joints welded in three kinds of welding was： end welding＋ 625 alloy welding wire＋ tungsten argon shielded arc welding process〉 end sealing＋ 625 alloy welding wire＋ tungsten argon shielded arc welding process〉 end sealing＋ flux cored wire welding process. The pitting corrosion resistance of welding seam and heat affected zone using end welding＋625 alloy welding wire＋tungsten argon shielded arc welding process was the best.