热处理对1Cr18Ni9Ti与2Cr13钢焊接接头断口组织形貌的影响

Effect of Heat Treatment on Fracture Microstructure and Image of 1Cr18Ni9Ti and 2Cr13 Steel Welded Joints

通过钨极氩弧焊方法,在一定工艺条件下对1Cr18Ni9Ti与2Cr13实施焊接,后对焊接接头进行焊后热处理。通过万能拉伸机对热处理前后的焊接接头进行拉伸试验,采用OM、SEM对1Cr18Ni9Ti与2Cr13钢热处理前后的焊接接头进行断口组织形貌观察及分析。结果表明,1Cr18Ni9Ti和2Cr13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+残余奥氏体+碳化物;热处理后焊缝组织转变为回火索氏体。拉伸时,热处理前后焊接接头断裂部位都发生在奥氏体不锈钢热影响区一侧,均属于韧性断裂,热处理前韧窝大小、分布不均匀;热处理后韧窝变小,分布均匀,大小尺寸均等。热处理前,焊接接头的抗拉强度约为635 MPa,伸长率约为26%,断面收缩率约为44%;热处理后,焊接接头的抗拉强度约为645 MPa,伸长率约为24%,断面收缩率约为44%。

By TIG, under certain welding craft conditions, 1Crl 8Ni9Ti and 2Crl 3 was welded, and certain heat treatment was carried out to welded joint. The fracture image and properties of 2Cr13 and 1Crl8Ni9Ti welded joints before and after heat treatment were observed by OM, SEM, electronic universal tensile machine and tensile experiments. The results show that before heat treatment, 2Cr13 and 1Crl8Ni9Ti welded joints is columnar crystal, the microstructure is lath martensite ＋ austenite ＋ carbide. After heat treatment, the structure changes from lath martensite into tempered sorbite. After tensile ,the fracture position of welded joints is HAZ of austenitic stainless steel, belong to toughness fracture. Before heat treatment, the dimple size and distribution are not uniform; after heat treatment, they are uniform. Before heat treatment, the tensile strength of the welded joints is about 635 MPa, elongation is 26%, reduction of area is 44%; after heat treatment, the tensile strength of the welded joints is about 645 MPa, elongation is 24%, reduction of area is 44%.