Ni_(42.2)W_(19.2)Fe_(18.9)B_(19.7)非晶合金的电化学腐蚀行为  

Electrochemical corrosion behavior of amorphous Ni_(42.2)W_(19.2)Fe_(18.9)B_(19.7) alloy

作　　者：刘文胜[1] 吴亚瑜[1] 马运柱[1] 张佳佳[1] 叶晓珊[1] 田海官 

机构地区：[1]r中南大学粉末冶金国家重点实验室,长沙410083

出　　处：《中国有色金属学报》2015年第8期2123-2130,共8页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(50774098)

摘　　要：采用单辊急冷法制备Ni42.2W19.2Fe18.9B19.7(摩尔分数,%)非晶合金。采用差热分析仪(DSC)和X射线衍射(XRD)分析非晶薄带的特征温度和析出相;采用电化学极化曲线及电化学阻抗法研究不同温度退火样品在3.5%NaCl(质量分数)溶液中的电化学腐蚀行为;采用扫描电镜(SEM)分析试样腐蚀后表面显微形貌,并采用能谱分析仪(EDS)和微区衍射仪分析表面成分。结果表明:使用单辊急冷法可以制备Ni42.2W19.2Fe18.9B19.7非晶合金,其玻璃转化温度为627℃,晶化温度为692℃。650℃退火试样的抗腐蚀性能优于750℃退火试样和非晶薄带的。在650℃退火试样表面形成致密钝化膜,因此具有良好的抗腐蚀性能;而在非晶薄带和750℃退火试样表面形成的钝化膜不稳定,易发生点蚀和局部腐蚀。Ni42.2W19.2Fels.9B19.7 （mole fraction, %） amorphous alloy was prepared by melt spinning method. The characteristic temperatures and precipitated phases of amorphous alloy were identified by differential scanning calorimeter （DSC） and X-ray diffractometer （XRD）. The electrochemical corrosion behaviors of the samples in 3.5% NaC1 （mass fraction） solution was studied by the linear polarization method and electrochemical impedance spectroscopy. The morphologies and components of samples after potentiodynamic polarization were observed and analyzed by scanning electron microscope （SEM）, energy dispersive spectrometer （EDS） and micro-zone X-ray diffractometer, respectively. The result shows that the Ni42.2W19.2Fe18.9B19.7 amorphous alloy could be prepared by melt spinning method. The glass transition temperature and crystallization temperature are about 627 and 692 ℃, respectively. Compared with as-spun sample and the sample annealed at 750 ℃, the anticorrosion property of the sample annealed at 650 ℃ is obviously improved. A stable passive film forms on the surface of sample annealed at 650 ℃, which leads to its excellent corrosion resistance. However, the passive films on the surfaces of the amorphous alloy and the sample annealed at 750 ℃ are not stable, which are susceptible to be attacked by pitting corrosion and localized corrosion.

关 键 词：非晶合金 极化曲线 交变阻抗 电化学腐蚀 

分 类 号：TG139[一般工业技术—材料科学与工程] TG171[金属学及工艺—合金]