According to the welding standard bl50 1998 steel pressure vessel, all new materials and new welding processes shall be subject to welding procedure qualification. Welding procedure evaluation shall be based on reliable steel welding performance test and shall be completed before product welding. Whether the stainless steel composite plate can pass the welding process audit is the key to the welding of stainless steel composite plate. At present, the welding procedure qualification of stainless steel composite plate shall be conducted in accordance with Appendix A of "welding procedure qualification of stainless steel composite steel", 4708-2000 of steel pressure vessel welding procedure qualification (appendix of the standard), and the body shall comply with the relevant standards.

　　不锈钢复合板焊接工艺不锈钢复合板的复合层(不锈钢)和基地层(碳钢、低合金钢等)复合轧制双金属、涂料确保耐腐蚀,强度主要是通过基地层,因此可以节省大量不锈钢,具有良好的经济价值。不锈钢复合板以其良好的综合性能和优势被广泛应用于石油化工、食品等行业。不锈钢复合板的焊接与不锈钢、碳钢或低合金钢的焊接不同。

　　Welding process of stainless steel composite plate the composite layer (stainless steel) and base layer (carbon steel, low alloy steel, etc.) of stainless steel composite plate composite rolling bimetal, coating ensure corrosion resistance, the strength is mainly through the base layer, so it can save a lot of stainless steel, with good economic value. Stainless steel composite plate is widely used in petrochemical, food and other industries because of its good comprehensive performance and price advantage. The welding of stainless steel composite plate is different from that of stainless steel, carbon steel or low alloy steel.

　　不锈钢复合板的特点不锈钢复合板的特点的复合工艺钎焊复合工艺使不同材料之间形成原子键合。高屈服强度的纯不锈钢板的屈服强度为。铝合金强度为190MPa、90MPa，且复合板屈服强度大于280MPa。焊接工艺评定焊接方法选用不锈钢复合板，根据复合板的材料和厚度，并结合现场施工情况，基材采用CO2气体熔焊、焊条电弧焊。CO2气体保护焊具有熔合量小、生产率高、成本低、焊接变形和应力小、焊接质量高等优点。焊条电弧焊熔合相对较小，灵活性较大，应用范围广。

　　Characteristics of stainless steel composite plate advanced composite process brazing composite process makes different materials form atomic bonding. The yield strength of pure stainless steel plate with high yield strength is. The strength of aluminum alloy is 190mpa and 90Mpa, and the yield strength of composite plate is more than 280mpa. According to the material and thickness of the composite plate, combined with the site construction situation, the base material adopts CO2 gas fusion welding and electrode arc welding. CO2 gas shielded welding has the advantages of small fusion, high productivity, low cost, small welding deformation and stress, high welding quality and so on. The fusion of electrode arc welding is relatively small, flexible and widely used.

　　不锈钢复合板过渡层焊接金属中存在的的主要问题在稀释由于焊接碳钢基层不含合金元素铬,镍,所以当焊缝金属的熔化合金元素铬、镍稀释效应,使焊接奥氏体形成元素铬、镍含量减少,可以产生在焊缝金属淬火马氏体组织,容易产生裂缝,从而恶化接头质量。因此，在焊接过渡层时，应使用含有较多铬和镍的焊接材料，即使被基体稀释，也不会产生马氏体硬化组织。同时，采用合适的焊接方法和焊接工艺，减少了底座一侧的焊接深度和焊缝稀释。

　　The main problem in the welding metal of the transition layer of stainless steel composite plate is the dilution. Because the base of the welding carbon steel does not contain alloy elements chromium and nickel, when the dilution effect of the melting alloy elements chromium and nickel of the weld metal reduces the content of the elements chromium and nickel formed in the welding austenite, it can be produced in the quenched martensite structure of the weld metal, which is easy to produce cracks, thus deteriorating the quality of the joint. Therefore, when welding the transition layer, the welding material containing more chromium and nickel should be used, even if it is diluted by the matrix, it will not produce martensitic hardening structure. At the same time, the proper welding method and welding process are adopted to reduce the welding depth and weld dilution on one side of the base.