酸洗和固溶处理对不锈钢抗点蚀性能的影响

研究了酸洗和固溶处理对 8种不锈钢钢筋电阻对焊接头抗点蚀能力的影响。研究发现 ,酸洗和固溶处理都能有效地改善和恢复不锈钢电阻对焊接头的抗点蚀性能。对于普通双相钢 ,固溶处理比酸洗能更有效地改善接头的抗点蚀性能 ,并无晶粒粗化现象 ;对于奥氏体钢和超级奥氏体钢 ,固溶处理的效果不及酸洗 ,且会引起母材晶粒粗化。对含Mo含N较高钢种的对焊接头 ,两者的效果更佳 ,尤其是两者综合处理后的接头 ,其临界点蚀温度CPT甚至高于对应母材经酸洗以后的CPT。文章对比分析了母材和固溶处理前后接头的显微组织 ,讨论了引起上述抗点蚀性能变化的原因。文章还探讨了酸洗和Mo、N元素可以改善不锈钢抗点蚀性能的机理。

Influences of Pickling and Solution Treatment on Pitting Corrosion Resistance of Stainless Steels

The effects of pickling and solution treatment on pitting corrosion resistance of stainless steel welded joints were studied.It was found that both pickling and solution treatment were considerably effective in improving and recovering the pitting corrosion resistance of all the investigated welds.For duplex steel welds the effect of solution treatment was more obvious than that of pickling without any grain growth.But for austenitic and super austenitic steel welds,solution treatment was less effective than pickling and caused grain growth in base metals.When both solution treatment and pickling were employed,the CPT of welds alloyed with higher amount of Mo and N was even higher than that of corresponding pickled base metals.The microstructures of base metal and welds before and after solution treatment were analyzed,and the reason,by which the pitting corrosion resistance of welds was improved,was discussed.In addition,the improving mechanism of pickling and the role of Mo and N in stainless steels were also described.