Q195钢双镀Galfan合金镀层组织及耐蚀性  

Microstructure and Corrosion Resistance of Two-step Hot-dipped Galfan Coating on Q195 Steel

作　　者：吴长军[1] 冯子跞 刘亚[1] 涂浩[1] 王建华[1] 苏旭平[1,2] 

机构地区：[1]常州大学江苏省材料表面科学与技术重点实验室,江苏常州213164 [2]常州大学江苏省光伏科学与工程协同创新中心,江苏常州213164

出　　处：《中国表面工程》2017年第5期52-59,共8页China Surface Engineering

基　　金：国家自然科学基金(51471037;51201023)~~

摘　　要：为在结构钢件表面获得质量优良的高耐蚀性Galfan合金镀层,尝试在450℃先预镀纯锌再浸镀Galfan合金的双镀方法,并研究预镀时间和浸镀时间对镀层组织及耐蚀性的影响。结果表明,450℃预镀5 s以上的纯锌后再浸镀Galfan合金,镀层表面质量优良。镀层主要由Fe_2Al_5-Znx、FeAl_3-Znx和合金液的凝固组织组成,没有Fe-Zn化合物。随预镀时间增加,FeAl3-Znx+G(液相凝固组织)层变厚;随浸镀时间的增加,Fe_2Al_5-Znx层厚度逐渐增加,并逐渐形成FeAl_3-Znx层。FeAl3-Znx+G两相层在浸镀60 s以下均能稳定存在。通过电化学测试发现,双镀Galfan合金镀层耐蚀性明显优于纯锌镀层,但延长浸镀Galfan合金时间会降低镀层的耐蚀性。To obtain high corrosion resistance Galfan coating on structural steel with excellent surface quality, the Q195 steel was pre-dipped in pure zinc bath before being immersed in Galfan bath at 450 ℃. The effects of the pre-dipping time and the immerse time on the microstructure and corrosion resistance of the coating were investigated. Experiment results show that the Galfan coating with excellent surface quality can be obtained after the steel is pre-dipped in zinc bath for more than 5 s. The coating is composed mainly of Fe2Al5-Znx, FeAl3-Znx and the solidification structure of the liquid phase, while no Fe-Zn compound is observed. With the increase of the pre-dipping time, the FeAI3-Znx＋G （coagulation structure of liquid phase） layer becomes thicker. With the increase of the immerse time in Galfan bath, the thickness of the Fe2Als-Znx layer increases gradually, and even forms a FeAl3-Znx layer. When the pre-dipped sample is immersed in Galfan bath for less than 60 s, the FeAl3-Znx＋G two-phase layer can stably exist. Electrochemical test results show that the corrosion resistance of the two-step hot-dipped Galfan coating is better than that of the pure zinc coating. However, the corrosion resistance decreases with prolonging immersion time in Galfan bath.

关 键 词：热浸镀 高尔凡 双镀 微观组织 

分 类 号：TG174.44[金属学及工艺—金属表面处理] TG113.23[金属学及工艺—金属学]