热处理制度对Ni_(3)Al和Stellite6堆焊层组织及性能的影响

Effect of Heat Treatment Regime on Microstructure and Properties of Ni_(3)Al and Stellite6 Surfacing Layers

司太立合金因其优异的高温耐磨性和抗氧化性,在核泵、阀门、汽轮机等产品中得到广泛应用,但该合金属于战略资源,价格昂贵,且易活化成强辐射元素。采用自主研制的Ni_(3)Al堆焊焊丝,与常用的Stellite6粉末进行焊接工艺性及性能对比,尤其针对650℃×4 h和870℃×4 h两种常用的热处理制度,研究两种堆焊层所发生的组织及性能变化。在304奥氏体不锈钢基材表面进行堆焊时,Ni_(3)Al焊丝和Stellite6粉末均具有良好的焊接工艺性。Ni_(3)Al堆焊层硬度高于Stellite6合金。随着热处理温度由650℃提高到870℃,Ni_(3)Al堆焊层的硬度呈下降趋势,而Stellite6的硬度呈上升趋势。经870℃×4 h热处理后,Ni_(3)Al堆焊层的硬度依然比Stellite 6堆焊层的硬度高68 HV2,对于该材料后续工程应用具有很好的参考价值。

Because of its excellent high temperature wear resistance and oxidation resistance,Stellite alloy is widely used in the nuclear pumps,valves,steam turbine,and other products,but it is the strategic resources,expensive,and easily activate into intense radiation elements.Use the independent development of Ni_(3)Al surfacing welding wire,and compare welding manufacturability and performance with the commonly used Stellite6 powder.Especially for the two commonly used heat treatment regimes of 650℃×4 h and 870℃×4 h,the microstructure and property changes of the two kinds of surfacing layer were studied.It is found that both Ni_(3)Al wire and Stellite6 powder have good welding performance when surfacing on 304 austenitic stainless steel.The hardness of Ni_(3)Al surfacing layer is higher than that of Stellite 6 alloy.With the increase of heat treatment temperature from 650℃to 870℃,the hardness of Ni_(3)Al surfacing layer decreased,while that of Stellite6 surfacing layer increased.After heat treatment at 870℃×4h,the hardness of Ni_(3)Al surfacing layer was still 68 HV2 higher than that of Stellite 6 surfacing layer which has a good reference value for the subsequent engineering application of the ma‐terial.