带极电渣堆焊在双金属冶金复合管纵缝覆层焊接中的应用

Application of electro-slag strip overlay welding for clad layer longitudinal weld seam welding of duplex metal metallurgy clad pipes

双金属冶金复合管的焊接工艺包括基层(碳钢层)焊接和覆层(不锈钢等合金层)焊接两个部分;在进行基层内焊埋弧焊接时,为保护不锈钢覆层的坡口不被基层内焊埋弧焊烧损,需匹配相应的焊接参数,但会导致基层内焊缝边沿与覆层坡口间出现沟槽,若直接在基层内焊缝上进行覆层的带极堆焊,将会在覆层焊缝中出现类似未熔合/夹渣类缺陷;通过采用不同覆层焊接工艺进行对比试验,选择覆层焊接采用自动TIG焊焊接基层内焊缝边沿+带极电渣堆焊工艺,该覆层焊接工艺可有效减少该类缺陷的产生;并通过试验验证了该工艺条件下的焊接接头的力学性能及覆层焊缝抗腐蚀性能等均满足标准要求。

The welding process of duplex metal metallurgy clad pipes include base metal(carbon steel)welding and clad layer(stainless steel or other alloy material)welding.In order to protect the milling groove of stainless steel layer from burning loss by base metal inside submerged arc welding,the proper welding parameters may be matched,but that base metal welding also will generate grooves between edges of base metal inside weld seam and milling groove of clad layer.If the strip overlay welding of clad layer was performed on the inside weld seam of base metal directly,the defects such as incomplete fusion or slag inclusion are easy to be found in the clad layer weld seam.Though comparing different clad layer welding procedures,auto TIG welding+electro-slag strip overlay welding were selected weld both edges of base metal inside welding seam and other clad layer area,respectively.After the inspection and test validation indicate that the clad layer welding procedure not only can effectively reduce defects,but also all the mechanical properties,corrosion-resistance and other requirements of welded joint also can meet standards requirements.