Hastelloy F型铸造镍基合金析出相形成规律及其对耐蚀性能的影响

Rule of the formation of precipitated phases in Cast Ni-base Hastelloy F alloy and their influences on the corrosion resistance of the alloy

采用金相显微镜、Ｘ射线衍射、电子探针和透射电镜相结合的方法，研究了耐“氧化－还原”复合介质的ＨｄｓｔｅｌｌｏｙＦ型铸造镍基合金中析出相形态、种类、成份、结构及形成条件，同时还研究了析出相和敏化时间对合金耐蚀性的影响。结果表明，ＨａｓｔｅｌｌｏｙＦ型合金在８００～１２００℃范围内，有Ｐ相、μ相、Ｍ＿（６ｃ）及少量σ相析出，９００℃左右析出量相对少些。这些析出相数量越多，富Ｃｒ、Ｍｏ越严重，合金耐点蚀和耐晶间腐蚀性能越差。敏化时间延长，亦使合金抗点蚀和抗晶间腐蚀性能有所下降，但对合金均匀腐蚀性能影响不大。

This paper investigates the morphology constituent,strruucture and formation condition of the precipitated phases in cast Ni-Cr-Mo containing Hastelloy-Falloy resistent to an“Oxidation-reduction”com- plex medium by using an optocal microsecope,x-ray diffraction-spectrum, EMPA and TEM,and also the influence of the precipitated phases and sensitization time on the corrosion resistance of the alloy.The results indicate that in the range 800℃ to 1200℃ there are P,μ,M_(6c) and a little phases precipitated in the alloy,the amount of which is less at about 900℃.The more the amount of the precipitated phases and the richer the Cr and Mo contained in the phases,the poorer the resistence to pitting and intergranuoar corrosion of the alloy. The prolongation of sensitization time will result in the decrease in the resistence to pitting and intergranular corrosion of the alloy,but has little influence on the general corrosion behaviour of the alloy.