合金元素Al对Ni-10%Fe基合金在熔融NaCl中腐蚀行为的影响（英文）  

Effect of Alloy Element Al on the Corrosion Behavior of Ni-10wt%Fe Based Alloy in Molten NaCl

作　　者：王军伟[1,2] 贾红光[1,2] 王智平[3] 朱侗 雷富军[1,2] 徐俊[2] 

机构地区：[1]高性能轻金属合金及深加工国家地方联合工程研究中心,青海西宁810016 [2]青海大学,青海西宁810016 [3]兰州理工大学,甘肃兰州730050

出　　处：《稀有金属材料与工程》2017年第1期57-62,共6页Rare Metal Materials and Engineering

基　　金：National Natural Science Foundation of China(51441003);Natural Science Foundation of Qinghai Province(2015-ZJ-931Q)

摘　　要：NaCl及其混合盐作为太阳能中高温相变储热介质有许多优点,但熔融氯化盐对金属储热容器材料具有强烈腐蚀性。研究了Al添加量(质量分数)分别为0%、5%和10%的3种Ni-10%Fe基合金(分别为1#、2#和3#)在850℃熔融NaCl中的腐蚀行为,分析了试样表面腐蚀产物和腐蚀残盐成分,对比了试样横截面腐蚀特征和元素变化趋势,探讨了腐蚀机制。结果表明,3种试样的腐蚀动力学曲线均满足线性腐蚀规律;添加Al的试样平均质量损失率大幅降低,2#和3#试样腐蚀速率分别为1#试样的12%和20%。原子量较小的Al优先于Fe、Ni被氧化和生成高温稳定性好的Al_2O_3 ,是腐蚀速率降低的两个主要原因。但Al含量较高(如10%)时,内部的Al原子向试样表面扩散较为容易,氧化膜较厚,且易于脱落,又导致腐蚀速率增大。Na Cl and its mixed salt have many advantages as a medium of solar energy phase change thermal storage at moderate and high temperature. But molten chloride has sharp corrosive action on metal thermal storage vessel. The corrosion behavior of three kinds of Ni-10 wt% Fe based alloy（1#, 2# and 3#） in 850 °C molten Na Cl was studied. The content of Al in 1#, 2# and 3# sample was 0.0 wt%, 5.0 wt% and 10.0 wt%, respectively. The components of Na Cl after corroding and corrosion products on samples surface were analyzed. Elements change trend and corrosion characteristics on cross section of the three samples were contrasted. Corrosion mechanisms were discussed finally. Results show that the kinetics curves of the three kinds of sample obey a liner rule. The average mass loss rate declines when Al is added in the sample. The rate of 2# and 3# is only 12% and 20% of that of 1#, respectively. There are two reasons for the value reduction： firstly, Al will be oxidized prior to oxidization of Fe or Ni, and the atomic mass of Al is small;secondly, Al_2O_3 is very stable at high temperature as corrosion products. However, when the content of Al is very high（for example 10wt% in here） in Ni-10 wt% Fe based alloy, Al oxidized on sample surface provides a convenient condition for Al atom transmission from sample inside to surface. Al_2O_3 film becomes thick and exfoliates easily. The exfoliation increases the average mass loss rate in turn.

关 键 词：腐蚀 熔融盐 NACL AL 

分 类 号：TG172[金属学及工艺—金属表面处理]