摘要
在A3钢表面Zn-Fe合金电镀液中加入镧盐,研究La^(3+)对Zn-Fe合金镀层在酸性介质中腐蚀行为的影响。用线性扫描伏安法和电化学阻抗法,研究Zn-Fe合金镀层在30℃的0.20mol/L H_2SO_4溶液中的腐蚀行为。用XRD和SEM研究Zn-Fe合金镀层在腐蚀前后的微观结构和形貌的变化。结果表明,加入镧盐没有改变Zn-Fe合金镀层的晶面择优取向,但影响各晶面衍射峰强度,使镀层结晶粒度变小;当加入La_2(SO_4)_3为0.90 g/L时,Zn-Fe合金镀层变得致密均匀,电结晶生长形态呈现层状;镀层的致钝电流密度(i_(pp))和维钝电流密度(i_p)显著降低,极化电阻R_p增大,镀层具有良好的耐蚀性能。
The effect of La^(3+) on the corrosion behavior of Zn-Fe alloy coating in acid solution were investigated.The corrosion behavior of Zn-Fe alloy coating was studied by the linear sweep voltammetry and AC impedance in 0.20 mol/L sulfuric acid solution at 30℃.The microstructure of Zn-Fe alloy coating before and after corrosion was studied by XRD and SEM.The results indicated that the grain size of Zn-Fe alloy coating turned smaller,the preferred orientation of Zn-Fe alloy coatings were not changed and the intension of diffraction for crystal planes were affected after adding lanthanum salt.When 0.90 g/L La_2(SO_4)_3 was added into the electrolytes,the coatings of Zn-Fe alloy were more uniform and close together,and the shape of electrocrystallization turned to layer.The i_(pp) and i_p of Zn-Fe alloy coating were reduced evidently,R_p was increased,and the Zn-Fe alloy coating had better corrosion resistance.
出处
《腐蚀与防护》
CAS
北大核心
2010年第12期966-969,共4页
Corrosion & Protection
基金
合肥市科技项目(080326D14)
关键词
镧盐
电镀
Zn-Fe合金镀层
耐蚀性
硫酸溶液
lanthanum salt
electroplating
Zn-Fe alloy coating
corrosion resistance
sulfuric acid solution