DD421单晶高温合金在无SO_(x)气氛下的低温热腐蚀硫化行为  

Sulfidation behavior in low-temperature hot corrosion of single crystal superalloy DD421 without SO_(x) atmosphere

作　　者：宋鹏[1,2] 姜祥伟 吴俊杰[1,2] 卢玉章 董加胜[2] 楼琅洪[2] SONG Peng;JIANG Xiang-wei;WU Jun-jie;LU Yu-zhang;DONG Jia-sheng;LOU Lang-hong(School of Materials Science and Engineering,University of Science and Technology of China,Hefei 230026,China;Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China)

机构地区：[1]中国科学技术大学材料科学与工程学院,合肥230026 [2]中国科学院金属研究所,沈阳110016

出　　处：《材料工程》2021年第6期109-115,共7页Journal of Materials Engineering

基　　金：国家科技重大专项(2017-Ⅵ-0019-0019,2017-Ⅶ-0008-0101)。

摘　　要：采用涂盐法研究表面涂覆有90%(质量分数,下同)Na_(2)SO_(4)+10%NaCl混合盐(750℃熔融态)和纯Na_(2)SO_(4)盐(750℃固态)的第二代镍基单晶高温合金DD421在750℃大气环境下(无SO_(x)气氛)的热腐蚀行为。结果表明:在熔融混合盐腐蚀介质中,硫化反应主要由液相熔融盐侵蚀所导致。热腐蚀100 h后合金腐蚀产物主要为典型的简单氧化物(Al_(2)O_(3),Cr_(2)O_(3),TiO_(2))以及Ni/Cr/Ti的硫化物。而在纯Na_(2)SO_(4)固态盐热腐蚀实验中,热腐蚀100 h后合金腐蚀产物与混合盐实验中的产物基本相同,但其腐蚀层厚度相对更薄,硫化物尺寸相对更大。结合热力学和微观组织分析,本研究明确了在无SO_(x)气氛的腐蚀环境下合金元素能够与固态Na_(2)SO_(4)盐发生硫化反应。The hot corrosion behavior of the second generation nickel base single crystal superalloy DD421 coated with 90%(mass fraction)Na_(2)SO_(4)+10%NaCl(molten at 750℃)and pure Na_(2)SO_(4)(solid state at 750℃)was investigated by salt coating method in 750℃atmosphere(without SO_(x) atmosphere).The results show that in the corrosion medium of molten mixed salt,the sulfidation reaction is mainly caused by the corrosion of liquid molten salt.After 100 h of hot corrosion,the main corrosion products are typical simple oxides(Al_(2)O_(3),Cr_(2)O_(3),TiO_(2)) and Ni/Cr/Ti sulfides.However,in the pure Na_(2)SO_(4) solid salt hot corrosion experiment,the corrosion products of the alloy after 100 h of hot corrosion are basically the same as those in the mixed salt test,but the thickness of the corrosion layer is relatively thinner and the size of sulfide is relatively larger.Combined with thermodynamics and microstructure analysis,it is clear that the alloy elements can react with solid Na_(2)SO_(4) salt in the corrosion environment without SO_(x) atmosphere.

关 键 词：高温合金 热腐蚀 硫化 固态反应 

分 类 号：TG132.32[一般工业技术—材料科学与工程]