机械传动部件用钢的表面处理及镀层耐蚀性

采用方波脉冲电沉积法对机械传动部件用钢(20Cr钢)进行表面处理。通过改变占空比,制备了五种Ni-Co/SiC复合镀层。通过浸泡腐蚀试验和电化学阻抗测试,研究了占空比对Ni-Co/SiC复合镀层耐蚀性的影响。结果表明:随着占空比从10%增大到40%,镀层的腐蚀速率降低,电荷转移电阻增大。当占空比为40%时,镀层表现出最佳的耐蚀性,其腐蚀速度最低,电荷转移电阻最大,在10%的盐酸溶液中遭受的腐蚀较轻。但当占空比大于40%时,随着占空比的增大,镀层的耐蚀性变差,腐蚀速率升高,电荷转移电阻减小。

Surface Treatment of Steel for Mechanical Transmission Parts and Corrosion Resistance of the Coating

Surface treatment of steel for mechanical transmission parts(20Cr steel)was carried out by using square-wave pulse electrodeposition method.Five kinds of Ni-Co/SiC composite coatings were prepared at different duty cycle.The influnece of duty cycle on the corrosion resistance of Ni-Co/SiC composite coatings was investigated by immersion corrosion test and electrochemical impedance measurement.The results showed that with the increase of duty cycle from 10%to 40%,the corrosion rate decreased while charge transfer resistance increased.When duty cycle was 40%,the coating exhibited the best corrosion resistance,with the lowest corrosion rate and the biggest charge transfer resistance,and its surface corrosion in 10%hydrochloric acid was slight.However,when duty cycle was higher than 40%,corrosion resistance of the coating was weakened.With the increase of duty cycle,the corrosion rate increased while charge transfer resistance decreased.