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为提高电站锅炉过热器铁素体－奥氏体异种钢焊接接头的高温蠕变断裂强度和延长服役寿命，设计了用专用镍基填充材料焊接的不锈钢－镍基焊缝－耐热钢三元组合接头。通过对不同焊缝接头的高温持久性能试验及用ＳＥＭ和ＥＰＭＡ对焊缝界面组织变化的对比分析，认为在高温低应力条件下接头早期失效的主要原因是熔合区及热影响区碳、铬等元素迁移和碳化物聚集所引起的蠕变断裂。组合接头的设计方案对改善接头应力分布，阻碍碳扩散和提高接头蠕变强度具有显著效果
In order to improve the high-temperature creep rupture strength and service life of ferritic-austenitic dissimilar steel welded joints of power plant boiler superheater, a stainless steel-nickel base weld-heat-resisting steel ternary alloy Combination connector. Through the comparison of high-temperature durability test of different weld joints and SEM and EPMA, the main reason of early failure of joint under high temperature and low stress is that the fusion zone and heat-affected zone carbon, chromium, etc. Element migration and accumulation of carbides caused by creep rupture. The design scheme of the composite joint has a significant effect on improving the stress distribution of the joint, hindering the carbon diffusion and improving the joint creep strength