NaNO_2对20SiMn低合金钢在3%NaCl溶液中空蚀损伤的缓蚀作用  

INHIBITION OF NaNO_2 ON CAVITATION CORROSION OF 20SiMn LOW ALLOY STEEL IN 3%NaCl SOLUTION

作　　者：骆素珍[1] 郑玉贵[1] 敬和民[1] 姚治铭[1] 柯伟[1] 

机构地区：[1]中国科学院金属研究所金属腐蚀与防护国家重点实验室,沈阳110016

出　　处：《腐蚀科学与防护技术》2004年第6期347-351,共5页Corrosion Science and Protection Technology

基　　金：国家重点基础研究专项经费 (G19990 65 0 ) ;国家自然科学基金 ( 5 0 2 710 78)

摘　　要：利用磁致伸缩空蚀实验机研究了 2 0SiMn低合金钢在 3%NaCl和 3%NaCl+NaNO2 溶液中的空蚀行为 .测量了静态和空蚀条件下的腐蚀电位变化、电化学阻抗谱和极化曲线 .结果表明 :NaNO2 通过抑制腐蚀与空蚀间的交互作用 ,对 2 0SiMn低合金钢在 3%NaCl溶液中的空蚀损伤有良好的抑制作用 ,浓度为 1%的NaNO2 的缓蚀效率达到80 2 % .添加NaNO2 对 2 0SiMn低合金钢在 3%NaCl溶液中的电化学行为有显著影响 .在 3%NaCl溶液中 ,自腐蚀电位、线性极化电阻都随空蚀进行而逐渐负移和减小 .与此相反 ,添加NaNO2 后 ,2 0SiMn的自腐蚀电位、线性极化电阻都随空蚀的进行而逐渐正移和增大 .3%NaCl+1%NaNO2 溶液中的电化学阻抗谱特征与空蚀表面形貌的变化有较好的对应关系 .The cavitation corrosion behavior of 20SiMn low alloy steel in 3% NaCl solution with or without sodium nitrite was investigated by using a magnetostrictive-induced cavitation facility.The polarization curves and electrochemical impedance spectroscopy (EIS) under quiescent and cavitating conditions were measured.The results showed that cavitation damage of 20SiMn low alloy steel could be inhibited by NaNO 2 through suppression of the synergism between corrosion and cavitation.With a given concentration of 1% NaNO 2,its inhibition efficiency under cavitating conditions was 80.2%.The addition of NaNO 2 strongly affected the electrochemical corrosion behavior of 20SiMn low alloy steel in 3% NaCl solution.The free corrosion potential and polarization resistance decreased with cavitation time in 3% NaCl solution.Conversely,with the addition of NaNO 2,the free corrosion potential and polarization resistance increase with cavitation time.The characteristic of EIS was in accordance with the morphologies of cavitated surface of 20SiMn low alloy steel in 3%NaCl+1%NaNO 2.

关 键 词：低合金钢 自腐蚀电位 3%NaCl溶液 空蚀 缓蚀作用 NaNO2 电化学阻抗谱 损伤 中空 抑制作用 

分 类 号：TQ124.3[化学工程—无机化工] TG174[金属学及工艺—金属表面处理]