摘要
氯化物熔盐是太阳能热发电储热系统具有前景的储热介质,但其对金属材料具有很强的腐蚀性。研究了太阳能热发电系统两种常用材料316L不锈钢和Inconel 625合金在900℃的NaCl、KCl、MgCl2和CaCl2熔盐中的腐蚀行为,采用XRD、带有能谱分析系统的扫描电镜分析了腐蚀产物的相组成和形貌。研究结果表明:两种材料在氯化物熔盐中均腐蚀严重,但在碱土金属氯化物熔盐(MgCl2、CaCl2)中的腐蚀程度要比它们在碱金属氯化物熔盐(NaCl、KCl)中严重得多。与Inconel 625合金相比,316L不锈钢在同种氯化物熔盐中的腐蚀速度较快。造成这种现象的原因是316L不锈钢表面的腐蚀产物FeCr2O4和Fe3O4比Inconel 625合金表面的腐蚀产物更易在氯化物熔盐中溶解。研究结果将有助于太阳能热发电系统的选材和发展腐蚀防护技术。
Chloride molten salts are potential thermal storage materials for solar thermal plant, however, they are very corrosive to metal alloys. The corrosion behaviors of two typical materials, 316L stainless steel and Inconel 625 alloy, in NaC1, KC1, MgCI2 and CaC12 molten salts at 900 ℃ were studied by using XRD and SEM equipped with EDS. Both of the two alloys endured sever corrosion in the four chloride molten salts, but the corrosion rates in alkali earth metal chloride molten salts （MgC12 and CaC12 ） were much faster than those in alkali metal chloride molten salts （NaC1 and KC1）. However, the corrosion rate of 316I. stainless steel was faster than that of the Inconel 625 alloy in the same chloride molten salt because the main oxides formed on the surface of 316L stainless, which are FeCr2 O4 and Fe3 O4, are easier to dissolve into the chloride molten salts than Cr2 O3 and NiCr2 O4 formed on the surface of Inconel 625 alloy. The results are helpful for the material selecting and developing of corrosion protection technique for the so- lar thermal plant system.
出处
《材料导报》
EI
CAS
CSCD
北大核心
2014年第14期109-113,共5页
Materials Reports
基金
国家自然科学基金(51201131)
陕西省科技新星项目(2013KJXX-42)
