YG15硬质合金电化学腐蚀机理研究  

Electrochemical Corrosion of YG15 Cemented Carbide

作　　者：施远 金洙吉[1] 姜冠楠[1] 刘作涛 周忠正 王泽北 SHI Yuan;JIN Zhiyi;JIANG Guannan;LIU Zuotao;ZHOU Zhongzheng;WANG Zebei(School of Mechanical Engineering, Dalian University of Technology, Dalian 116024, China)

机构地区：[1]大连理工大学机械工程学院

出　　处：《中国腐蚀与防护学报》2019年第3期253-259,共7页Journal of Chinese Society For Corrosion and Protection

基　　金：国家重点基础研究发展计划(2015CB057304);基础科研科学挑战计划(JCKY2016212A506-0107和JCKY2016212A506-0103);国家创新研究群体科学基金(51621064)~~

摘　　要：针对电解磨削加工YG15硬质合金中的电化学腐蚀现象,使用3 mol/L的NaNO3电解液,采用动电位和恒电位腐蚀相结合的实验方法进行机理研究。结果表明,在NaNO3电解液中YG15硬质合金的电化学腐蚀是WC和Co共同被氧化;且当阳极电位过高时,结合剂金属Co的溶解速率变大,材料表面生成的腐蚀产物与基体之间结合力较低,易发生脱落;同时产生电流波动现象,材料表面腐蚀严重。在实际加工中,应尽量避免阳极电位超过3.5 VAg/AgCl。通过EDS检测和XPS分析确定腐蚀产物成分为WO3。选择合理的电压参数会对电解磨削中增大材料的去除率有较大的帮助。Cemented carbide is widely used in many fields because of its good properties. However,it is difficult to be processed with traditional machining methods. Electrochemical grinding is a kind of nontraditional method which combines electrochemical machining and mechanical grinding with great processing quality and high removal rate. In this paper, electrochemical corrosion mechanism of YG15 cemented carbide in electrolyte of 3 mol/L NaNO3 is focused by means of potentiodynamic-and potentiostatic-curve measurements. Results show that the electrochemical corrosion of YG15 cemented carbide in NaNO3 electrolyte is the result of co-oxidation corrosion of WC and Co. Corrosion phenomena vary a lot under different potentials. Moreover, when the anode potential is high, the dissolution rate of metal Co(which acts as the binder) increases, leading to the decreasing adhesion of the formed corrosion product scale to the substrate, which makes the corrosion product scale is prone to spall off. In addition, the corrosion dissolution of the substrate and the spall off for the corrosion product scale may cause the current oscillations on curves of corrosion current vs time, which leads to serious corrosion and even destruction of the substrate surface. Therefore, the anode potential should not excess 3.5 VAg/AgClso that to avoid the above mentioned harmful event during electrochemical grinding. The composition of the corrosion layer is determined to be tungsten oxides(which is mainly WO3) by energy dispersive spectroscope and X-ray photoelectron spectroscope. Reasonable voltage parameters could help increase the removal rate of materials a lot in electrochemical grinding.

关 键 词：碳化钨硬质合金 电解磨削 动电位 恒电位 电化学腐蚀 

分 类 号：TQ150.1[化学工程—电化学工业]