焊后热处理对1Cr18Ni9Ti与2Cr13钢焊接接头组织和性能的影响

通过钨极氩弧焊方法,对1Cr18Ni9Ti与2Cr13钢实施焊接,并对焊接接头整体进行焊后热处理。采用OM、SEM对2Cr13与1Cr18Ni9Ti钢热处理前后的焊接接头组织进行分析,利用显微硬度计、电子万能拉伸机测量了焊接接头的力学性能。结果表明,1Cr18Ni9Ti和2Cr13钢焊接接头热处理前焊缝组织为典型的柱状晶,组织为板条马氏体+残留奥氏体+碳化物;热处理后焊缝组织为回火索氏体,而且碳化物析出量也明显增多。拉伸时,热处理前后焊接接头断裂的部位都发生在奥氏体不锈钢热影响区一侧,热处理前后焊接接头的抗拉强度分别约为635.56、649.44 MPa;焊缝区的显微硬度分别约为276、222 HV0.5,热处理后焊接接头的整体显微硬度比热处理前的明显降低。

Effect of post-welding heat treatment on microstructure and mechanical properties of 1Cr18Ni9Ti and 2Cr13 steel welded joints

By method of tungsten inert gas welding,1Cr18Ni9Ti and 2Cr13 steels were welded,and heat treatment was carried on the welded joint.By OM and SEM,the microstructure of 2Cr13 and 1Cr18Ni9Ti steels welded joints was analyzed before and after heat treatment.Mechanical properties of the welded joints were measured by micro-hardness tester and electronic universal tensile machine.The results show that before heat treatment,2Cr13 and 1Cr18Ni9Ti steels welded joint is typical columnar crystal,the microstructure is lath martensite+restained austenite+carbide,After heat treatment,the microstructure changes from lath martensite into tempered sorbite,and carbide quantity also increases significantly.The position of fracture is at the heat affected zone of austenitic stainless steel.Before and after heat treatment,the tensile strength of welded joints is about 635.56,649.44 MPa respectively;micro-hardness of welded zone 1Cr18Ni9Ti and 2Cr13 steels is about 276,222 HV0.5 respectively.After heat treatment,the micro-hardness of all welded joint decreases obviously.