热处理对1Cr18Ni9Ti与2Cr13钢板焊接接头耐腐蚀性的影响

Effect of heat treatment on corrosion resistance of 1Cr18Ni9Ti and 2Cr13 steel plate welded joint

通过填丝钨极氩弧焊方法对1Cr18Ni9Ti与2Cr13钢板进行焊接,并对焊接接头进行焊后热处理。采用SEM对焊接接头热处理前后的组织进行观察及分析;采用模拟海水浸泡试验,测量了焊接接头的交流抗阻和极化曲线。结果表明,1Cr18Ni9Ti和2Cr13钢板焊接接头热处理前焊缝为典型的柱状晶,组织为板条马氏体+奥氏体+第二相;热处理后焊缝组织为回火索氏体+奥氏体+第二相。热处理前后,焊接接头耐腐蚀性由强到弱的顺序都为:奥氏体母材>奥氏体侧热影响区>焊缝区>马氏体侧热影响区>马氏体母材。对比而言,热处理后焊接接头中马氏体母材区的耐蚀性略有升高,其他区域均有下降。

1Cr18Ni9Ti and 2Cr13 steel plates were welded by TIG welding with adding welding materials,and post-weld heat treatment was carried out.The welded joint microstructure before and after heat treatment was observed and analyzed by means of SEM.The AC impedance and polarization curves of the welded joint were measured by simulated immersion test.The results show that the welded joint of 1Cr18Ni9Ti and 2Cr13 steel plate before heat treatment is a typical columnar crystal,and the structure is composed of lath martensite+austenite+second phase.The microstructure of welded joints after heat treatment is composed of tempered sorbite+austenite+second phase.Both the corrosion resistance order of welded joints before or after heat treatment from strong to weak is as follows:austenite base material>heat affected zone near austenite side>welded joint zone>heat affected zone near martensite side>martensite base material.In contrast,the corrosion resistance of martensite base material in the welded joint after heat treatment increases slightly,while the other areas decreases.