预氧化处理温度对镍铝涂层耐腐蚀性能的影响  

Effect of Different Pre-oxidation Temperature on Corrosion Resistance of Ni-Al Coatings to High Temperature Chloride Molten Salt

作　　者：许世鹏 郑月红[1] 占发琦 喇培清 XU Shipeng;ZHENG Yuehong;ZHAN Faqi;LA Peiqing(State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of Technology,Lanzhou 730050,China;Gansu Key Laboratory of Solar Power System Engineering,Jiuquan Vocational and Technical College,Jiuquan 735000,China)

机构地区：[1]兰州理工大学有色金属先进加工与再利用国家重点实验室,兰州730050 [2]酒泉职业技术学院甘肃省太阳能发电系统重点实验室,酒泉735000

出　　处：《材料研究学报》2024年第12期922-931,共10页Chinese Journal of Materials Research

基　　金：甘肃省自然科学基金(22JR5RF1078);酒泉市科技支撑计划(2023CA2067);甘肃省太阳能发电系统重点实验室开放课题(2024SPKL02)。

摘　　要：将磁控溅射制备的镍铝涂层在不同温度预氧化成氧化膜,然后将其在氯化物混合熔盐中进行高温腐蚀,研究了这种氧化膜的微观结构和镍铝涂层耐高温氯化物熔盐腐蚀的性能。结果表明:将镍铝涂层在1000℃预氧化生成了连续致密的氧化膜;在800和900℃预氧化不能生成完整连续致密的氧化膜;而在1100℃预氧化虽然能生成氧化膜,但是基体元素向涂层扩散在表面生成铁的颗粒状物质,使其耐蚀性降低。镍铝涂层在1000℃预氧化生成的氧化膜在800℃的高温氯化物熔盐腐蚀100 h后没有显著的变化,表明其具有较高的耐高温腐蚀性。其原因是,生成的连续完整的α-Al_(2)O_(3)层保护了基底。高温腐蚀时扩散到涂层中的铬元素含量明显提高,表明高温腐蚀促进了基体中铬元素的扩散和析出。The chloride-based molten salt is expected to be the next generation of heat storage medium for concentrated solar power technology.However,the chloride-based molten salts have severer corrosive effect to the relevant metallic structural parts at elevated temperatures.In this paper,Ni-Al coatings were prepared on Ni-based alloy IN 625 by magnetron sputtering technique.Then the coated alloys were pre-oxidized in air at different temperatures.Next,the corrosion behavior of the pre-oxidized coatings in the mixed chloride molten salts at 800oC was assessed via immersion test.Meanwhile,the formed oxide scales due to pre-oxidation treatment,and the variation of the pre-oxidized scales after immersion test were also characterized.The results show that a continuous and dense oxide scale can form when the pre-oxidation at 1000oC.When the pre-oxidation at 800 and 900oC,a complete and continuous dense oxide scale cannot form,and when the pre-oxidation at 1100oC,although an oxide scale will form,but a large number of nodular oxides generate on the top surface of the pre-formed oxide scale due to the rapid outwards diffusion of alloying elements from the substrate during pre-oxidation,which is not conducive to the corrosion resistance of the coating.After corrosion in molten chloride salts at 800oC for 100 h,the Ni-Al coated IN 625 alloy pre-oxidized at 1000oC presented only little mass change,indicating that the coating has good high-temperature corrosion resistance,this may mainly be due to the formation of a complete and continuous oxide scale ofα-Al_(2)O_(3),which plays role in anti-corrosion protection for the substrate.With the progress of high temperature corrosion,the Cr content in the coating increases obviously,indicating that high temperature promotes the outward diffusion of Cr atoms from the substrate.

关 键 词：金属材料 耐蚀材料 预氧化 氯化物熔盐 

分 类 号：O484[理学—固体物理]