双镀层对A_3钢在硫酸溶液中腐蚀速率的影响

Corrosion Rate of Two-coated A_3 Steel in Sulfuric Acid Solution

尝试在A3钢表面施镀镍+铅双镀层,以提高其在硫酸溶液中的耐蚀性能。利用腐蚀失重方法分别测定了镀铅层与镀镍+铅双镀层的A3钢在硫酸中的腐蚀速率,并借助扫描电镜对双镀层的形态进行了观察与分析。试验表明:施镀镍+铅双镀层能明显提高A3钢的耐蚀性能。认为:镍层遮盖了A3钢表面,使阳极电位提高,腐蚀驱动力减小;铅在硫酸中析氢超电压大,且容易生成致密的硫酸铅膜,这些因素是材料耐蚀性得到明显提高的重要原因。

Ni ＋ Pb coatings are electrodeposited on the surface of A3 steel in order to decrease the corrosion of A3 steel in sulfuric acid solution with different concentration. The corrosion rate of A3 steel with Pb or Ni ＋ Pb coating is carried out by weight loss method. The morphology of Ni ＋ Pb coatings are observed and analyzed with scanning electron microscopy. Experiment results show that the two coatings on A3 steel will markedly increase A3 steel anticorrosion, which will owe to the important factors such as the protection effect of coated Ni on the surface of A3 steel, high hydrogen over-voltage on lead coating and compact lead sulfate film. The anticorrosion mechanics of the two coatings in sulfuric acid solution are discussed.