表面粗糙度对硝酸钝化304不锈钢点蚀行为影响  

Influence of Surface Roughness on Pitting Corrosion Behaviors of 304 Stainless Steel Passivated with Nitric Acid

作　　者：王梅丰[1] 魏红阳[1] 陈东初[2] 万斌 倪磊[1] 刘桂宏[1] 李光东[1] 

机构地区：[1]南昌航空大学材料科学与工程学院,南昌330063 [2]佛山科学技术学院理学院,佛山528137 [3]上海民航职业技术学院,上海200232

出　　处：《腐蚀与防护》2015年第12期1156-1160,1165,共6页Corrosion & Protection

基　　金：佛山市科技计划项目(2014AG10009);佛山市高明区产学研项目(201205)

摘　　要：采用动电位扫描、电化学阻抗谱和电化学噪声等方法研究了不同表面粗糙度的304不锈钢在体积分数10%HNO3溶液中钝化后的耐蚀性。结果表明,随304不锈钢钝化前表面粗糙度从0.25μm降到0.10μm,电荷转移电阻从6.51kΩ·cm2上升到19.17kΩ·cm2,电位标准偏差和电流标准偏差降低,而噪声电阻增大;随表面粗糙度的增大,试样电位和电流的功率密度曲线线性部分的斜率均出现增大,谱噪声曲线线性部分的斜率下降,表明在光滑的不锈钢表面更容易形成致密稳定且耐腐蚀性强的氧化膜,硝酸钝化能显著改善304不锈钢耐点蚀性能。After passivation in 10vol% HNO3 solution,the corrosion resistance of 304 stainless steel samples with different surface roughnesses were studied with potentiodynamic scan,electrochemical impedance spectroscopy（EIS）and electrochemical noise（EN）.The results show that when the surface roughness decreased from 0.25μm to0.1μm,the charge-transfer resistance raised from 6.51kΩ·cm^2 to 19.17kΩ·cm^2,current standard deviation and potential standard deviation decreased,but noise resistance increased.The slopes of line segment in power spectral density（PSD）curves of potential and current increased,but the slope of noise spectrum curve decreased with the increase of surface roughnesses of samples,indicating that compact and stable passivation film was easily formed on the smooth surface of stainless steel.HNO3 passivation could markedly improve the pitting corrosion resistance of 304 stainless steel.

关 键 词：304不锈钢 点腐蚀 动电位扫描 电化学噪声 电化学阻抗谱 

分 类 号：TG174[金属学及工艺—金属表面处理]