【摘要】 采用电化学阻抗谱法(EIS),研究了20%、35%、50%的钼酸铵、硼酸、磷酸分别替代铬酐后的达克罗涂层的耐蚀性能。结果表明:铬酐替代量为20%时,钼酸铵、硼酸和磷酸替代的复合防护层的耐蚀性均优于未替代涂层;铬酐替代量为35%时钼酸铵和磷酸替代的复合防护层性能优异;铬酐替代量为50%时,磷酸替代的复合涂层耐蚀性最好;磷酸、硼酸、钼酸铵替代后生成的沉淀物填充了达克罗涂层中的空隙,使涂层的叠层结构更为致密,阻挡了腐蚀介质的扩散,减缓了工件的腐蚀。更多还原

【Abstract】 Electrochemical impedance spectroscopy(EIS) was used to study the corrosion resistance of dacromet coating that chromic anhydride in dacromet coating be substituted partly by ammonium molybdate, boric acid and phosphoric acid of 20%, 35%, 50% respectively.The results showed that when replacement amount is 20%, the corrosion resistance of composite protective coating that be substituted by ammonium molybdate, boric acid and phosphoric acid is all better than the unsubstituted coating.The replacement amount of chromic anhydride is 35%, the corrosion resistance of ammonium molybdate and phosphoric acid is excellent.The corrosion resistance of dacromet coating substituted by phosphoric acid is the best in 50% replacement.After substituted, phosphoric acid, boric acid, ammonium molybdate generated the sediments to fill the interspace of dacromet coating, made laminated structure of coating more compact, resisted spread of the corrosive medium, slow down corrosion of workpiece.更多还原