热镀锌钢板表面硅烷膜的制备工艺与耐蚀性能

Preparation and Corrosion Resistance of Silane Film on Hot-dip Galvanized Steel

采用正交试验结合中性盐雾试验和极化曲线测定等方法,研究了热镀锌钢板表面的硅烷膜在制备过程中的硅烷体积分数、水解溶剂中甲醇体积分数、水解时间、水解温度、溶液pH值、浸涂时间等因素对硅烷膜耐蚀性能的影响,并确定了最佳成膜工艺,讨论了硅烷膜作用机理。结果表明:最佳成膜工艺为硅烷体积分数7%、溶液pH值4、水解溶剂中甲醇体积分数10%、水解温度40℃、水解时间6 h、浸涂时间120 s,采用该工艺制备硅烷膜可明显推迟热镀锌钢板出现白锈的时间;硅烷膜同时也抑制了热镀锌钢板在腐蚀过程中阳极和阴极的反应,显著改善了热镀锌钢板的耐蚀性能。

A nontoxic silanized treatment process for hot-dip galvanized steel was investigated by the orthogonal experiment. The protection of silane films on galvanized steel surface was evaluated by neutral salt spray test and polarization test. The factors affecting the corrosion resistance of silane films were discussed, including concentration of silane solution, concentration of methanol, hydrolysis time, hydrolysis temperature, pH of silane solution and immersion time. The optimum technological parameters were obtained, and the mechanism was analyzed. The results show that the silane films had the optimum anti-corrosion properties under the conditions of concentration of the silane solution 7%, concentration of methanol in hydrolysis solvents 10%, hydrolysis time 6 h, hydrolysis temperature 40℃, pH of the silane solution 4 and immersion time 120 s acted as a physical barrier of galvanized steel and suppressed both cathodic and anodic reactions of corrosion simultaneously. The time of white rust oceurence on galvanized coating was delayed. The silane films obtained excellent corrosion resistance under the optimum technological conditions.