Inconel 718及其渗铝涂层在Na_(2)SO_(4)+5%NaCl混合盐膜下的热腐蚀行为  

Hot Corrosion Behavior of Inconel 718 Without and With Aluminide Coating in Air Beneath a Thin Film of Salt Mixture of Na_(2)SO_(4)+5%NaCl

作　　者：胡琪 耿树江[1] 王金龙[1] 王福会[1] 孙清云 吴勇 夏思瑶 HU Qi;GENG Shujiang;WANG Jinlong;WANG Fuhui;SUN Qingyun;WU Yong;XIA Siyao(Shenyang National Laboratory for Materials Science,Northeastern University,Shenyang 110819,China;China Academy of Machinery Wuhan Research Institute of Materials Protection Co.,Ltd.,Wuhan 430030,China)

机构地区：[1]东北大学、沈阳材料科学国家研究中心东北大学联合研究分部,沈阳110819 [2]中国机械总院集团武汉材料保护研究所有限公司,武汉430030

出　　处：《中国腐蚀与防护学报》2024年第3期623-634,共12页Journal of Chinese Society For Corrosion and Protection

基　　金：国家重点研发计划(2020YFB2010400);湖北省重点研发计划(2021BAA210)。

摘　　要：采用化学气相沉积(CVD)工艺在镍基高温合金Inconel 718上制备了铝化物涂层,研究了Inconel 718合金及其渗铝涂层在750,850和950℃空气中Na_(2)SO_(4)+5%(质量分数)NaCl混合盐膜下的热腐蚀行为。结果表明:基体表现出较差的抗腐蚀性能,且温度越高腐蚀越严重;腐蚀初期表面腐蚀产物主要由Cr_(2)O_(3)和Fe_(2)O_(3)组成,而随着腐蚀时间增加,尖晶石为主要腐蚀产物。此外,基体合金在850和950℃时的腐蚀膜疏松多孔,观察到开裂和剥落,抗腐蚀能力差;而渗铝涂层表现良好,腐蚀期间表面会形成Al_(2)O_(3)膜,极大提高了基体合金的抗腐蚀性能。虽然当腐蚀温度升高或腐蚀时间增加时,涂层会发生明显退化,且会导致腐蚀膜出现裂纹、孔洞等缺陷,其与涂层结合不紧密,但仍能在很大程度上有效保护基体。Aluminide coating was prepared on Inconel 718 superalloy by chemical vapor deposition(CVD).The hot corrosion behavior of Inconel 718 without and with aluminide coating beneath a thin film of salt mixture of Na_(2)SO_(4)(95%)+NaCl(5%)in air at 750,850 and 950℃was studied respectively.The results indicate that Inconel 718 alloy shows poor corrosion resistance,and the higher the temperature,the more serious the corrosion.In the early stage of hot corrosion,the surface corrosion products are mainly composed of Cr_(2)O_(3)and Fe_(2)O_(3).As the corrosion time increases,spinel oxide becomes the main corrosion products.In addition,the scale on Inconel 718 alloy formed at 850 and 950℃is loose and porous,while cracking and peeling were observed.For the aluminide coated alloy,it performs well with en-hanced corrosion resistance,while an Al_(2)O_(3)scale is formed on the coating surface during corrosion.Although the coating underwent significant degradation with the increasing corrosion temperature and/or corrosion time.Besides,the formed corrosion scale is not tightly boned to the coating,while the defects such as cracks or voids are observed.Even so,the coating can still protect the substrate effectively to a great extent.

关 键 词：Inconel 718 CVD渗铝涂层 Na_(2)SO_(4)+5%NaCl 热腐蚀 

分 类 号：TG174[金属学及工艺—金属表面处理]