特材管道接头焊接工艺优化及效果测试研究

Study on optimization of welding process and effect test of special pipe joint

试验采用全自动钨极氩弧焊(TIG)工艺和多层焊道焊接方式,对2205双相不锈钢管进行焊接,并研究焊接头性能。结果表明:焊缝组织中两相分布均匀,而热影响区组织中奥氏体较少,铁素体较多,但均符合应用要求;焊接头的抗拉强度超过母材标准强度620 MPa,延伸率超过母材标准延伸率25%,经180°弯曲试验后无裂纹萌生,焊接头拉伸、弯曲性能良好,焊接头各区域的硬度不超过硬度指标要求290 HV 10,硬度性能良好,焊接头焊缝的自腐蚀电流密度和自腐蚀电位分别为3.3248×10^(-8)A/cm^(2)、-165.5 mV,焊接头耐腐蚀性能良好。

This experiment used fully automatic tungsten inert gas(TIG)welding process and multi-layer welding method to weld 2205 duplex stainless steel pipes,and studied the performance of the welding joints.The test results show that the two phases in the weld structure are evenly distributed,while the heat-affected zone has less austenite and more ferrite,which meet the application requirements.The tensile strength of the welded joint exceeds the standard strength of the base material by 620 MPa,and the elongation rate exceeds the standard elongation rate of the base material by 25%.After 180°bending test,there is no crack initiation,and the tensile and bending performance of the welded joint is good.The hardness of each area of the welding joint does not exceed the hardness index requirement of 290 HV 10,and the hardness performance is good.The self corrosion current density I and self corrosion potential E of the welded joint are 3.3248×10^(-8)A/cm^(2)and-165.5 mV,respectively.The welding joint has good corrosion resistance.In summary,the welding joint prepared in this experiment has good comprehensive performance and meets the requirements of engineering applications.