过滤净化对K640S返回料力学性能的影响

Effect of Filtration on Mechanical Properties of Cobalt-base Superalloy K640S

对铸造钴基高温合金K640S返回合金进行过滤净化处理,测试合金化学成分、拉伸性能和蠕变性能·结果表明:过滤明显降低合金中的O、N元素的质量分数,而其他主要元素质量分数没有变化·过滤对合金拉伸性能没有明显影响·在815℃、205MPa条件下,过滤合金与未过滤合金相比,蠕变寿命从34h提高到64h·过滤后合金组织中显微疏松明显减少·可见,返回合金经过滤处理后,其性能已达到新料的性能水平·

Effect of filtration on composition, microstructure and mechanical properties of cobaltbase superalloy K640S was investigated. The results show that the filtration treatment can effectively decrease the content of O and N elements and increase creep life of the recycled superalloy K640S remarkably at the condition of 815?℃, 205?MPa. But, the filtration treatment has no influnce on the tensile property of the superalloy. The microstructure of the virgin superalloy K640S and the filtration treated recycle alloy consist of the same skeletonlike carbides in form of M23C6 and the flakelike carbides in form of M7C3 distributed among the dendrites and at grain boundary in γ matrix. From the present data, it is suggested that superalloy K640S can still offer payoffs as a structural material in gas turbine application after filtration recyle.