城市输水用Q235B+304不锈钢复合管环焊焊接工艺

Girth welding process of Q235B+304 stainless steel clad pipe using in urban water supply system

不锈钢复合管内侧为具有耐腐蚀性能的不锈钢,外侧为具有一定强度的碳钢,成为新一代环保型输水管。为了研究8 mm+2 mm厚城市输水用Q235B+304不锈钢复合钢管的环焊焊接工艺,试验选用合理的焊接材料及坡口形式等,获得了复合板与复合板、复合板与碳钢板的焊接接头。通过拉伸、冲击、弯曲试验评价两种焊接接头的力学性能;通过检测接头不锈钢焊道化学成分,评估复合管焊接接头内侧不锈钢焊道的耐晶间腐蚀性能。结果表明,所采用的焊接工艺获得的接头力学性能满足技术要求且富余量较大,复合管接头不锈钢焊缝获得了A+(5%~10%)δ组织,耐晶间腐蚀性能优异。

The inner side of the stainless steel clad pipe is stainless steel with good corrosion resistance,and the outer side of the pipe is carbon steel with a certain strength. It has become a new generation of environment-friendly water pipe. In order to study the welding process of Q235B＋304 stainless steel clad pipe with （ 8＋2 ） mm thickness for water transportation in city,reasonable welding material and groove type were selected to obtain two welded joints, The mechanical properties of the two welded joints were evaluated by tensile, impact and bending tests. The intergranular corrosion resistance of the stainless steel welded joint was evaluated by the chemical composition of the joint. The results show that the mechanics of the joint obtained by the welding process meets the technical requirements and the surplus is large, the A＋（ 5%-10% ） 8 microstructure is obtained in the stainless steel weld of the pipe joint,and has excellent resistance to intergranular corrosion.