摘要
将304、316不锈钢和Inconel 617镍基合金在565℃硝酸熔盐(60%NaNO_3+40%KNO_3,质量分数)中进行长时静态腐蚀试验,对比研究了3种材料的腐蚀动力学曲线以及表面腐蚀形貌、物相组成和微区成分。结果表明:3种材料均发生了氧化腐蚀,其中304和316不锈钢具有抛物线型的腐蚀动力学特征,而Inconel 617镍基合金在短暂质量增加之后出现了明显的腐蚀质量损失现象;Inconel 617镍基合金的耐腐蚀性能最好,304不锈钢的最差;在腐蚀初期,304、316不锈钢表面均形成了针状和片状腐蚀产物,随着腐蚀时间的延长,腐蚀产物转变为尖晶石结构,Inconel 617镍基合金表面的腐蚀产物呈颗粒状,随着腐蚀时间的延长,部分颗粒变大;304和316不锈钢表面均形成了以Fe_2O_3和(Fe,Cr)_3O_4为主的腐蚀产物层,Inconel 617镍基合金表面则形成了以NiO和CoO为主的腐蚀产物层。
Long-time immersion corrosion experiments were conducted on 304,316 stainless steels and Inconel 617 Ni-based alloy in molten nitrate salt(60 wt%NaNO3+40 wt%KNO3)at 565 ℃.The corrosion kinetic curves and corrosion morphology,phase composition and microcomposition on surface of the three materials were studied and compared.The results show that oxidation corrosion occurred on the three materials.In addition,304 and 316 stainless steels had parabolic corrosion kinetic characteristcs,while Inconel 617 Ni-based alloy exhibited significant corrosion mass loss after a brief mass increase.The corrosion resistance of Inconel 617 alloy was the best and that of 304 stainless steel was the worst.In the initial stage of corrosion,acicular and flaky corrosion products were formed on surfaces of 304 and 316 stainless steels;with increasing corrosion time,the corrosion products changed into spinel structure.The corrosion products on surface of Inconel 617 Ni-based alloy were granular,and some particles became larger with increasing corrosion time.The corrosion product layers on surfaces of 304 and 316 stainless steels were mainly composed of Fe2O3 and(Fe,Cr)3O4,while that on surface of Inconel 617 Ni-based alloy was mainly composed of NiO and CoO.
作者
张学文
李洪川
李生云
薛伟伟
刘坤
唐建群
巩建鸣
ZHANG Xuewen;LI Hongchuan;LI Shengyun;XUE Weiwei;LIU Kun;TANG Jianqun;GONG Jianming(Key Lab of Design and Manufacture of Extreme Pressure Equipment, School of Mechanical and Power Engineering,Nanjing Tech University, Nanjing 211816,China;Huanghe Hydropower Development Co.,Ltd.,Xining 810008,China)
出处
《机械工程材料》
CAS
CSCD
北大核心
2019年第5期24-29,共6页
Materials For Mechanical Engineering
关键词
不锈钢
镍基合金
硝酸熔盐
氧化
腐蚀产物
stainless steel
Ni-based alloy
molten nitrate salt
oxidation
corrosion product
