20钢玻璃内衬防腐管与304不锈钢管对接工艺分析

Study on Butt Welding Process of 20 Steel Glass Lining Anticorrosion Tube and 304 Stainless Steel Pipe

对于20钢玻璃内衬防腐管与304不锈钢钢管对接选用和耐蚀堆焊层相同的材料AT-ERNi625焊丝进行打底,填充盖面分别选择了AT-ERNi625焊丝和304焊丝,采用拉伸、弯曲试验、显微硬度试验测试焊接接头力学性能;通过扫描电镜、光学显微镜对焊缝断口及显微组织进行分析。结果表明,焊缝抗拉强度大于20钢抗拉强度,其显微硬度从母材到焊缝,从盖面层到打底层都呈现下降趋势,其力学性能满足使用要求;在母材20钢一侧出现了脱碳层,焊缝一侧出现增碳层,焊缝中的组织主要是少量的针状铁素体和奥氏体。

For 20 steel glass lining anticorrosion tube and 304 stainless steel pipe butt welding, it selected AT-ERNi625 welding wire to conduct backing, which is the same material as corrosion resistant surfacing layer. Filling and covering respectively chose ERNi625 welding wire and 304 welding wire. The mechanical properties of welded joints were tested by tensile test and microhardness test, and the weld fracture and microstructure were analyzed by scanning electron microscope, optical microscope. The results indicated that the tensile strength of weld is higher than that of 20 steel, and the microhardness present a downward trend from base metal to weld, from covering welding layer to backing layer. The mechanical properties can meet application requirements. The decarburization layer appeared at the side of the parent metal 20 steel, and recarburization layer appeared at the side of weld. The organization in weld mainly consist of a small amount of acicular ferrite and austenite.