625堆焊冶金式双金属复合管堆焊层稀释率的研究

The research of dilution rate of surfacing layer of 625 surfacing metallurgical bimetallic composite pipe

采用热丝TIG在DNV GL450D表面整管堆焊UNS N06625,研究焊接工艺参数对冶金式双金属复合管堆焊层稀释率的影响。应用直读光谱仪及光学显微镜等对堆焊层的元素含量以及显微组织进行分析,采用失重法测定堆焊层腐蚀速率。结果表明:随着焊接电流的减小,钨极尖端钝边直径的增大,焊丝直径的增大,堆焊过程中母材熔化减少,堆焊稀释率降低。堆焊层中铁元素含量随之减少,显微组织更加细化,分布更加均匀,耐腐蚀性能也有所提高。

UNS N06625 was welded on DNV GL450D by hot wire TIG,and the influence of welding process parameters on the dilution ratio of surfacing layer of metallurgical bimetallic composite pipe was studied.The element content and microstructure of surfacing layer were analyzed by direct reading spectrometer and optical microscope,and the corrosion rate of surfacing layer was measured by weight loss method.The results show that with the decrease of welding current,the diameter of blunt edge of tungsten electrode tip and the diameter of welding wire increase,the melting of base metal and the dilution rate of surfacing decrease.The content of iron in the surfacing layer is reduced,the microstructure is finer,the distribution is more uniform,and the corrosion resistance is improved.