冷凝液pH对消声器用409不锈钢腐蚀行为的影响  

Effect of pH on Condensate Corrosion of Type 409 Stainless Steel for Automotive Mufflers

作　　者：马荣耀[1] 李谋成[1] 沈嘉年[1] 

机构地区：[1]上海大学材料研究所结构重点实验室,上海200072

出　　处：《腐蚀与防护》2015年第5期448-452,共5页Corrosion & Protection

基　　金：国家自然科学基金(51134010)

摘　　要：采用极化曲线和电化学阻抗谱研究了消声器用409不锈钢在不同pH冷凝液中的腐蚀行为,并用X射线光电子能谱(XPS)分析了pH对409不锈钢钝化膜化学组成的影响。结果表明,试样在冷凝液pH为2时处于活化腐蚀状态,而冷凝液pH不低于3时处于钝化状态;在酸性条件下钝化膜富含铬的化合物、缺陷较多,试样腐蚀阻力相对较小,而在中/碱性条件下钝化膜富含铁的化合物、缺陷较少,试样腐蚀阻力较大。The corrosion behavior of type 409 stainless steel in simulated muffler condensates with different pH values was studied by polarization curves and electrochemical impedance spectroscopy （EIS）. The composition of passive films formed on 409 SS surfaces was analyzed by XPS. The results showed that 409 SS was in active corrosion state as pH was equal to 2, while it changed to passive state as pH increased to 3. The passive films formed under acidic conditions enriched in Cr-compounds with many defects while they enriched in Fe-compounds under neutral and alkaline conditions with less defects. As a result, 409 SS showed much higher corrosion resistance in the neutral and alkaline condensate solutions than in the acidic ones.

关 键 词：汽车消声器 不锈钢 冷凝液腐蚀 PH 钝化膜 

分 类 号：TG174[金属学及工艺—金属表面处理]