热镀锌层上磷化/硅烷处理复合膜的耐蚀性研究  

Corrsion Resistance of Phosphating/Silane Composite Film on Hot-Dip Galvanized Steel Sheet

作　　者：尤伟[1] 卢锦堂[1] 林碧兰[1] 

机构地区：[1]华南理工大学材料科学与工程学院,广东广州510640

出　　处：《材料保护》2008年第3期34-36,57,共4页Materials Protection

摘　　要：将已磷化的热镀锌钢板经双-[3-(三乙氧基)硅丙基]硫化物(BTESPT)硅烷溶液封闭处理后,可以获得高耐蚀性的复合膜。通过SEM、EDS、电化学极化测量和NSS试验研究了复合膜组成和耐蚀性。结果表明,经硅烷封闭处理后,磷化膜上磷酸锌晶体间的微孔隙被硅烷膜填补,从而在锌层表面形成了连续、完整、致密的复合膜;经磷化300 s、硅烷封闭处理后,复合膜的极化电阻Rp显著增大,腐蚀电流密度Jcorr显著减小,NSS试验5个周期未出现白锈,耐蚀性能优异。A composite film was prepared on the surface of hot - dip galvanized steel sheet by phosphating and treatment with bis-[trie-thoxysilylpropyl] tetrasulfide ( BTESPT) silane. The composition andmicrostructure of the composite film were analyzed by means of scanning electron microscopy and energy dispersive spectrometry, while its corrosion resistance was evaluated using electrochemical polarization measurement and neutral salt-spray test. It was found that the micro-pores in the phosphating coating of the hot-dip galvanized steel were sealed by silane film after being post - treated with BTESPT solution, and a continuous, compact and complete composite coating was subsequently formed. After being phospha-ted for 300 s and post-treated with BTSEPT solution, the resulting composite coating had greatly increased polarization resistance Rp, significantly decreased corrosion current density, and was free ofwhite rust after 5 cycle neutral aalt-spary test.

关 键 词：热镀锌钢 磷化 硅烷 封闭处理 复合膜 耐蚀性 

分 类 号：TG174.4[金属学及工艺—金属表面处理]