【摘要】 采用热丝TIG堆焊工艺在30CrMo钢基体上堆焊Inconel 625镍基合金，分析对比不同预热温度对堆焊接头和堆焊层组织及性能的影响，从而确定合理的热丝TIG堆焊工艺。结果表明：Inconel 625镍基合金与30CrMo钢母材界面结合良好，无焊接缺陷；预热温度对堆焊层成型形貌、耐蚀性、接头弯曲性能影响很小，各温度下接头弯曲性能良好，均没有出现开裂现象，但对热影响区的硬度以及堆焊层的熔合比影响显著；各温度堆焊层显微组织均为树枝状奥氏体，由内而外过渡为胞状晶、柱状晶、树枝晶、等轴晶；堆焊后在母材、热影响区和堆焊层3个区域中，Fe、Ni、Cr、Mo、Nb等主要元素呈规律性分布，在枝晶间存在Mo、Nb元素的偏析；从堆焊效率、稀释率、堆焊试样性能考虑，焊前预热200℃最佳。更多还原

【Abstract】 The Inconel 625 nickel based alloy was deposited on 30CrMo steel substrate using hot wire TIG welding process. The effects of different preheating temperatures on the microstructure and properties of deposited joint and layer were analyzed and compared, through which a reasonable hot wire TIG welding process was determined. It is found that Inconel 625 nickel based alloy presents good bonding with 30CrMo steel base material, and there are no welding defects. The preheating temperature has slight effect on the formation morphology, corrosion resistance, and joint bending performance of the overly layer. The bending performance of the base metal joint is good at all temperatures, and there is no cracking phenomenon. However it has a significant impact on the hardness of the heat affected zone and the fusion ratio of the overly layer. The microstructure of each temperature overly layer is dendritic austenite, transitioning from inside to outer into cellular, columnar, dendritic, and equiaxed crystals. After surfacing, the main elements such as Fe, Ni, Cr, Mo, and Nb are distributed regularly in the base metal, heat affected zone, and surfacing layer. There is segregation of Mo and Nb elements between dendrites. Considering the welding efficiency, dilution rate, and performance of the welding specimen, preheating 200 ℃ before welding is the best.更多还原