AZ31铸轧镁合金植酸转化成膜过程机理研究  

Study on Forming Mechanism of Phytic Acid Conversion Film on AZ31 Cast and Rolled Magnesium Alloy

作　　者：行舒乐 肖伟中 车威 张艳山 王木乐 XING Shule;XIAO Weizhong;CHE Wei;ZHANG Yanshan;WANG Mule(School of Mechanical and Energy Engineering,Huanghuai University,Zhumadian 463000,China;Petroleum Engineering and Technology Institute,Zhongyuan Oilfield Branch Company of Sinopec,Puyang 457001,China)

机构地区：[1]黄淮学院机械与能源工程学院,河南驻马店463000 [2]中石化中原油田分公司石油工程技术研究院,河南濮阳457001

出　　处：《热加工工艺》2022年第4期95-99,共5页Hot Working Technology

基　　金：国家科技重大专项项目(2016ZX05017002);河南省重点研发与推广专项(科技攻关)项目(212102310400)。

摘　　要：分别采用扫描电子显微镜(SEM)和Leica光学显微镜(OM)观察了AZ31铸轧镁合金板材的表面组织和其植酸转化膜表面形貌,利用电化学工作站监测铸轧板的植酸转化膜成膜过程的电位-转化时间曲线,通过OM、极化曲线等方法分析了转化时间对转化膜表面形貌及腐蚀速率的影响,研究并分析了铸轧镁合金转化膜的成膜机理。结果表明:转化膜形成过程主要包括快速溶解、成膜初期、成膜中期和成膜后期4个阶段;转化膜主要由大量的等轴状的网纹膜组成,网纹膜尺寸随处理时间的增加而减小,而网纹宽度则增大;转化膜的腐蚀速率随处理时间的延长呈现先减小后增加的趋势,这与转化膜的结构、致密性相关。阳极极化过程主要以孔蚀和丝状腐蚀为主,这主要与铸轧板存在的微观裂纹缺陷有关。The surface microstructure and phytic acid conversion film surface morphology of AZ31 cast and rolled magnesium alloy sheet were observed by SEM and Leica optical microscope.The potential-time curve of phytic acid conversion film during forming process on casting and rolling plate was monitored by electrochemical workstation.The effects of conversion time on the surface morphology and corrosion rate of the conversion film were analyzed by OM and polarization curve.The forming mechanism of the cast and rolled magnesium alloy conversion film was studied and analyzed.The results show that,the formation process of the conversion film mainly includes four stages:the rapid dissolution,the early stage of film formation,the middle stage of film formation and the later stage of film formation.The conversion film is mainly composed of a large number of isometric reticulated films.The size of reticulated film decreases with the increase of treatment time,while the width between reticulated films increases.The corrosion rate of the conversion film decreases at first and then increases with the prolongation of treatment time.This is related to the structure and compactness of the conversion membrane.The anodic dissolution process is mainly pore corrosion and filamentous corrosion,which is mainly related to the microcrack defects of cast and rolled plate.

关 键 词：铸轧镁合金 植酸转化膜 极化曲线 腐蚀速率 

分 类 号：TG174[金属学及工艺—金属表面处理] TG146.22[金属学及工艺—金属学]