固溶+时效处理对钴基合金组织演变和腐蚀行为的影响  

Effects of solid solution and aging treatments on microstructure evolution and corrosion behavior of Co-based alloys

作　　者：王珂胜 石增敏[1,2] 朱哲 申烁 戴雷 吴海华[1,2] WANG Kesheng;SHI Zengmin;ZHU Zhe;SHEN Shuo;DAI Lei;WU Haihua(Hubei Engineering Research Center for Graphite Additive Manufacturing Technology and Equipment,China Three Gorges University,Yichang 443002,China;Hubei Key Laboratory of Hydroelectric Machinery Design and Maintenance,China Three Gorges University,Yichang 443002,China)

机构地区：[1]三峡大学石墨增材制造技术与装备湖北省工程研究中心,宜昌443002 [2]三峡大学水电机械设备设计与维护湖北省重点实验室,宜昌443002

出　　处：《中国有色金属学报》2025年第2期557-572,共16页The Chinese Journal of Nonferrous Metals

基　　金：湖北省重点实验室开放基金资助项目(2020KJX01)。

摘　　要：采用电弧熔炼方法制备了CoCrMoNi合金,研究了铸态合金固溶和时效处理中的组织演变规律及组织的耐腐蚀性能。结果表明:铸态合金的γ-FCC+ε-HCP两相组织胞状枝晶结构随固溶处理逐渐消失转变为等轴晶结构,同时发生ε-HCP相向γ-FCC相的转变和合金元素的相间扩散;γ-FCC相的层错条纹随晶粒粗化而生长,形成与ε-HCP板条相间分布形貌,层错密度随固溶时间先增大而后降低。固溶合金时效处理过程中发生γ-FCC相向ε-HCP相的逆转变、层错缺陷的湮灭和M_(23)C_(6)碳化物的析出。固溶合金的强度和伸长率随固溶时间先增加而后降低;时效合金的强度和伸长率随时效时间的延长而增加。固溶处理可提高合金的耐氯盐腐蚀性能,时效处理则降低合金的耐腐蚀性能。γ-FCC和ε-HCP两相体积分数及形貌分布是决定合金塑性和耐腐蚀性能的主要因素。As-cast cobalt-chromium-molybdenum-nickel(CoCrMoNi)alloys were prepared by arc melting,and the microstructure evolution and corrosion resistance of the as-cast alloys during the solid-solution and aging treatment processes were investigated.The results show that the as-cast samples show a typical dual-phase dendrite microstructure of the face centered cubic(γ-FCC)crystal and the hexagonal closest packing(ε-HCP)crystal.The as-cast dendrite gradually evolves to have the characteristic of equiaxial grains with the solution treatment time,accompanied by theγ-FCC phase transformation fromε-HCP phase and the alloying elements interphase diffusion;the stacking faults in theγ-FCC phase grow as the grain coarsens,resulting in the morphologies of interphase distribution of laminar stacking faults withε-HCP lathes,and the density of stacking faults firstly increases and then decreases.It occurs the inverse transformation fromγ-FCC phase toε-HCP phase,the annihilation of the fault striations and the precipitation of M_(23)C_(6) type carbides in solid-solution alloys during the aging stage.The strength and elongation of solid-solution-treated alloys firstly increases and then decreases with the solid-solution time,whereas the strength and elongation of the aging alloys are significantly improved with the increase of the aging time.The solid-solution enhances the corrosion resistance of the alloy to the chloride salts,while the aging reduces the corrosion resistance of the alloy.The volume fraction and morphology distribution characteristics ofγ-FCC andε-HCP phases are the main factors determining the plasticity and corrosion resistance of CoCrMoNi alloys.

关 键 词：钴铬钼镍合金 固溶处理 时效 层错 耐腐蚀性 

分 类 号：TG142.1[一般工业技术—材料科学与工程]