激光选区熔化Inconel 625合金的高温热腐蚀行为  

Hot corrosion behavior of Inconel 625 alloys fabricated by selective laser melting

作　　者：赵斌 王琪霖 任延杰[1,2] 韩林虎 蒋东方 ZHAO Bin;WANG Qilin;REN Yanjie;HAN Linhu;JIANG Dongfang(School of Energy and Power Engineering,Changsha University of Science&Technology,Changsha 410083,China;School of Mechanical&Energy Engineering,Zhejiang University of Science&Technology,Hangzhou 310023,China;State Grid Energy Research Institute Co.,Ltd.,Beijing 102209,China)

机构地区：[1]长沙理工大学能源与动力工程学院,长沙410083 [2]浙江科技大学机械与能源工程学院,杭州310023 [3]国网能源研究院有限公司,北京102209

出　　处：《中国有色金属学报》2024年第6期2030-2042,共13页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(52171066);湖南省教育厅重点项目(21A0204)。

摘　　要：采用电化学阻抗谱对比研究了激光选区熔化(Selective laser melting,SLM)和轧制Inconel 625合金在600℃覆盖50%KCl+50%Na_(2)SO_(4)(质量分数)盐膜时的电化学腐蚀行为。结果表明:SLM Inconel 625合金的腐蚀电化学阻抗谱呈双容抗特征,腐蚀过程受荷电离子迁移控制;轧制Inconel 625合金由高频段的容抗弧和低频段的直线组成,表明腐蚀受扩散控制;SLM Inconel 625合金的腐蚀产物层为Cr_(2)O_(3)/Ni_(3)S_(2)多层交替结构,而轧制Inconel 625合金表面腐蚀产物由Cr_(2)O_(3)和NiO的混合物组成,存在明显的内硫化现象;SLM Inconel 625合金较多的位错及亚晶粒促进了铬元素向外扩散并与氧发生反应,改变了合金表面的硫分压,进而影响了合金表面腐蚀产物膜的组成及结构。The hot corrosion behavior of Inconel 625 alloy fabricated by forged and selective laser melting(SLM)under 50%KCl+50%Na_(2)SO_(4)(mass fraction,%)salt film at 600℃was studied by electrochemical impedance spectroscopy.The results show that Nyquist plots of SLM Inconel 625 is composed of double capacitive loops,indicating that the corrosion is controlled by the charged transfer process through the scale.The Nyquist plots of forged Inconel 625 consist of a capacitive loop in high frequency zone with a line in low frequency zone,indicating that the corrosion is controlled by a diffusion process.The scale formed on SLM Inconel 625 shows a Cr_(2)O_(3)/Ni_(3)S_(2)multilayer alternating structure,while the scale formed on the forged Inconel 625 alloys is composed of a mixture of Cr_(2)O_(3)and NiO with the internal sulfidation occurred.A large amount of dislocations and subgrains in the SLM Inconel 625 alloy promote the outward diffusion of chromium.The prompt oxidation of Cr alters sulfur partial pressure on the alloy,which affects the composition and structure of the scale formed on SLM alloy.

关 键 词：热腐蚀 激光选区熔化 Inconel 625 电化学阻抗谱 位错密度 

分 类 号：TG174[金属学及工艺—金属表面处理]