热镀锌层三价铬钝化后的封孔工艺研究

研究热镀锌层三价铬钝化后不同封孔剂对封孔后镀层耐蚀性能的影响规律。用水性丙烯酸树脂、硅酸钠和硅烷偶联剂3种封孔剂对三价铬钝化后的镀锌层进行封孔处理,采用乙酸铅点滴试验、中性盐雾试验、极化曲线测定等方法对镀层耐腐蚀性进行对比分析。结果表明:采用丙烯酸树脂封孔的样品耐腐蚀性最好,其耐盐雾时间为120 h。乙酸铅点滴时间为173 s,自腐蚀电位为-0.693 V,极化电阻为5 673.2Ω·cm2。

Research of hole sealing technology after hot-dip galvanizing layer trivalent chromium passivation

To research influence role of different hole sealing agent after hot-dip galvanizing layer trivalent chromium passi- vation on galvanizing layer corrosion resistance after hole sealing. Three hole sealing agents such as water-based acrylic res- in, sodium silicate, silance coupling agent were adopted to seal hole treatment on hot-dip galvanizing layer after trivalent chromium passivation, the galvanizing layer corrosion resistance was contrastively analyzed by adopting the methods such as lead acetate spot titration test, neutral salt spray test, polarization curve measurement etc. Results show that the corrosion resistance of sample adopting acrylic resin hole sealing is the best, its salt spray resistance time is 120 h, lead acetate spot titration time is 173 s, self corrosion potential is -0. 693 V, polarization resistance is 5 673.2 Ω· cm2.