Corrosion behavior of extrusion, under-aged, peaked-aged and over-aged WE93 alloys in Na HSO_3 solutions

作     者：蒋全通 马鸣龙 张奎 李兴刚 李永军 石国梁 袁家伟 

作者机构：State Key Lab for Non-ferrous Metals and Process General Research Institute for Non-ferrous Metals 

出 版 物：《Journal of Rare Earths》 (稀土学报（英文版）)

年 卷 期：2014年第32卷第12期

页      面：1170-1174页

核心收录：

学科分类：08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：Project supported by National Natural Science Foundation of China(51204020) National Basic Research Program of China(2013CB632202,2013CB632205) 

主　　题：corrosion behaviors WE93 alloy Na HSO3 rare earths 

摘      要：The corrosion behaviors of extrusion, under-aged, peaked-aged and over-aged WE93 alloys in Na HSO3 solutions were investigated by optical microscopy（OM）, scanning electron microscopy（SEM） and X-ray diffraction（XRD）.The weight loss rates, corrosion morphologies and polarization curves were *** peak-aged specimen in Na HSO3 salt spray had the highest corrosion rate of 0.9787 mg/cm2/d, while extrusion specimen led to the lowest of 0.2184 mg/cm2/*** specimens could be arranged in decreasing order of corrosion rates： extrusion 〈under-aged〈over-aged〈peak-aged. Polarization curves also gave effective evaluation of corrosion rates in agreement. The NaHSO3 played a great role in the corrosion behaviors of WE93 alloys. The main reasons were that HSO3- developed a reaction： O2＋2HSO3 ＋2e→2HSO42→2H＋＋2SO42- to generate H＋, accelerating the process of corrosion reaction. SO4 2- stimulated corrosion and led to an autocatalytic type of reaction： MgZ＋＋SO4^2-＋7H2O→MgSO4-7H2O. XRD characterized that Mg（OH）2 and MgSO4·7H2O were the main corrosion products.