不同涂层处理的汽车紧固件用ST12冷轧钢与SS400热轧钢的电偶腐蚀行为研究  

Galvanic Corrosion Behavior of Couples of Hot Rolled Steel SS400 and Cold Rolled Steel ST12 with Two Coatings

作　　者：赵晓宏 郭泉忠[2] 杜克勤[2] 郭兴华[2] 王勇[2] 

机构地区：[1]中国第一汽车股份有限公司技术中心,长春130000 [2]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：《中国腐蚀与防护学报》2015年第1期86-90,共5页Journal of Chinese Society For Corrosion and Protection

摘　　要：采用极化曲线和电偶电位-时间曲线等方法,研究了在3.5%NaCl(质量分数)溶液中,经无铬锌铝涂层以及电镀锌镍合金涂层处理后的ST12冷轧钢与SS400热轧钢偶接后的电偶腐蚀行为。结果表明:相比无铬锌铝涂层,经电镀锌镍处理的ST12/SS400电偶对电偶腐蚀反应的驱动力小,电偶电位更正,电偶电流密度更小,耐电偶腐蚀性能最好,而且,锌镍镀层自腐蚀速率低。因此,电镀锌镍涂层更适合替代纯Zn镀层,对汽车工业中紧固件进行表面处理。Galvanic corrosion behavior of couples of cold rolled steel SS400 and hot rolled steel ST12 with chrome-free Zn/Al coating or Zn/Ni alloy electroplating was studied in 3.5%NaCl(mass fraction) solution by means of potentiodynamic polarization and galvanic method. The results showed that the couple of SS400 and ST12 with Zn/Ni alloy electroplating exhibited a weaker tendency of galvanic corrosion, a higher open circuit potential and a smaller galvanic current rather than that with chrome-free Zn/Al coating. While the free-corrosion current of Zn/Ni alloy electroplating coating was smaller than that of Zn/Al coating. Therefore, Zn/Ni alloy electroplating is extremely promising coating for the auto-mobile fastener to replace the traditional Zn electroplating.

关 键 词：电偶腐蚀 无铬锌铝达克罗涂层 电镀锌镍合金涂层 极化曲线 

分 类 号：TG172[金属学及工艺—金属表面处理] TG174.4[金属学及工艺—金属学]