【摘要】 为了进一步提高脉冲镀锌层的性能,采用双脉冲电沉积技术在Q235钢表面电镀纳米晶光亮锌层。采用X射线衍射(XRD)、扫描电镜(SEM)研究了锌镀层的相结构﹑择优晶面取向和表面形貌,并用谢乐公式计算了锌镀层的晶粒尺寸;通过极化曲线测试了锌镀层的耐蚀性;研究了光亮剂浓度、硫酸铈用量对锌镀层晶粒尺寸和耐蚀性的影响。结果表明:锌镀层均为直系六方结构,主要晶面取向为(100),(101)和(110);随光亮剂浓度的增加,镀层的平均晶粒尺寸减小,耐蚀性先增大后减小,光亮剂浓度为16 m L/L时,镀层耐蚀性最好;随镀液中硫酸铈浓度的增加,镀层的平均晶粒尺寸整体变化不大,镀层的耐蚀性先减小后增大再减小,0.4 g/L时最好。更多还原

【Abstract】 A series of nanocrystalline bright Zn coatings were prepared on Q235 low carbon steel substrate by pulse reverse electrodeposition so as to improve the corrosion resistance.The phase composition and preferred crystallographic orientations as well as morphology of as-prepared Zn coatings were analyzed by X-ray diffraction and scanning electron microscopy,and their grain size was calculated with Scherrer formula.Furthermore,the corrosion resistance of Zn coalings was examined by Tafel polarization curve method,and the effects of brightener concentration and cerium sulfate dosage on the grain size and corrosion resistance of the Zn coatings were investigated.Results indicated that the as-prepared Zn coatings had hexagonal structure as well as preferred orientations along(100),(101) and(110) planes.With the increase of the brightener concentration,the average grain size of the Zn coatings tended to decline,and their corrosion resistance tended to rise initially but decline later therewith;and the Zn coating obtained at a brightener concentration of 16 mL/L exhibited the best corrosion resistance.Moreover,the average grain size of the Zn coatings remained nearly unchanged with increasing dosage of cerium sulfate;and the corrosion resistance tended to sequentially decline,rise,and decline again therewith.Particularly,the Zn coating obtained at a cerium sulfate dosage of 0.4 g/L exhibited the best corrosion resistance.更多还原