Process Optimization and Corrosion Resistance of Silane Films on Cold Rolled Steel by Orthogonal Experiment

The silane film is one of environmental techniques of metal surface pretreatment.The optimal technological conditions of γ-aminopropyltriethoxysilane(γ-APS) films on the surface of cold rolled steel(CRS) were studied using orthogonal experiment.The corrosion resistance of the optimal films in 3.5% NaCl solution was analyzed by linear sweep voltammetry experiments and EIS,and the morphology changes were investigated by SEM.The results indicated that the optimal process conditions were 100 ml solution containing 3 ml γ-APS(pH=12),the ratio of the ethanol to water was 22∶75,hydrolysis temperature 30 ℃,hydrolysis time 8 h,coating time 15 min,curing temperature 120 ℃,curing time 15 min.The obtained silane films on CRS had good corrosion resistance in 3.5% NaCl solution.