The corrosion resistance of deformed galvannealed coatings
The galvannealed coating with different degrees of deformation had been prepared under exerting 10% 、20% and 30% uniaxial tensile strain on the galvannealed steel sheet (GA).The corrosion resistance between the different degrees of deformation and the loss in the extent of corrosion protection offered by these coatings in 3.5wt.% NaCl solution has been established by carrying out electrochemical studies such as potentiodynamic polarization and electrochemical impedance spectroscopy.The surface morphology of different deformed coatings for stretching and corrosion was characterized by scanning electron microscopy.The results show that the alternating-current impedance of GA coatings decreased with the increase of deformation,and the decrease was especially signification during the initial stage of deformation.The corrosion current of the GA coatings was first decreased and then increased,which indicated that the GA coating provided high electricity-maintaining capacity when the deformation was 10%.The pitting corrosion first taken place inside cracks of the GA coating after deformation,both the depth and area of corrosion increased with the degree of deformation.When the deformation was 30%,the cracks on surface of GA coating were widened to the extent that they were no longer preferred sites for corrosion.
uniaxial tensile polarization curve EIS surface morphology galvannealed coating
YUAN Xun-hua JIANG She-ming GUO Da-wei ZHONG Hai-feng GU Bao-shan ZHANG Qi-fu
National Engineering Lab Advanced Coating Technology for Metal Materials Central Iron & Steel Research Institute,Beijing 100081 China
国际会议
Asia Steel International conference 2012(第五届亚洲钢铁大会)
北京
英文
1-8
2012-09-23（万方平台首次上网日期，不代表论文的发表时间）