T92钢700℃下料浆渗铝机理研究  

Growth Mechanism of Aluminide Coating on T92 Steel Prepared by Slurry Aluminizing at 700℃

作　　者：龚兵兵 刘光明[1] 安春香 梅林波 张帮彦 GONG Bingbing;LIU Guangming;AN Chunxiang;MEI Linbo;ZHANG Bangyan(School of Materials Science and Engineering,Nanchang Hangkong University,Nanchang 330063,China;Shanghai Electric Power Plant Equipment Co.Ltd.,Steam Turbine Plant,Shanghai 201306,China)

机构地区：[1]南昌航空大学材料科学与工程学院,南昌330063 [2]上海电气电站设备有限公司汽轮机厂,上海201306

出　　处：《中国腐蚀与防护学报》2023年第3期587-593,共7页Journal of Chinese Society For Corrosion and Protection

基　　金：国家自然科学基金(51961028)。

摘　　要：采用料浆渗铝法在T92钢上开展了渗铝工艺研究,测试了700℃料浆层厚度约80μm渗铝层生长动力学,采用XRD、SEM及EDS对渗铝层表面物相结构和渗铝层截面形貌、厚度和成分进行研究。结果表明:渗铝的前3 h活性Al原子([Al])向内扩散形成Fe_(2)Al_(5)(η)相;随后[Al]开始在料浆层与渗铝层界面堆积,此时,Fe以较快的速度向外扩散并形成Fe_(2)Al_(5)(η)和FeAl3(θ)混合相外层;10 h后在渗铝层内部可以清晰观察到Fe Al(B2)相层。从动力学和热力学角度探讨了渗铝层扩散及生长过程机理。[Al]向内扩散形成的η相层厚度随时间变化可用x=18.40t^(1/2)-4.80表达。The aluminizing process of T92 steel was conducted by slurry aluminizing method.The growth kinetics of the aluminized layer with a slurry layer thickness of about 80μm at 700℃was tested.The surface and cross-sectional morphology and composition of the aluminide coating were characterized by using SEM,EDS and XRD respectively.The results show that the active Al atoms([Al])diffused inward to form Fe_(2)Al_(5)(η)phase in the first three hours of aluminizing.Then[Al]began to accumulate at the interface of the slurry/the formed aluminide coating,while Fe diffused outward rapidly resulted in the formation of the outer portion of the coating composed of mixed-phases Fe_(2)Al_(5)(η)and FeAl3(θ).After 10 h,the inner portion of FeAl(B2)phase could be clearly observed in the aluminized coatings.The mechanism of aluminized coating growth process and the relevant diffusion process of metallic components was discussed from the point of view of kinetics and thermodynamics.The thickness of theη-phase layer formed by the diffusion of[Al]with time can be expressed by equation of x=18.40t^(1/2)-4.80.

关 键 词：T92钢 料浆渗铝 动力学 热力学 

分 类 号：TG174[金属学及工艺—金属表面处理]