真空高频感应熔覆Ni60-WC复合涂层的耐蚀性

在不同的WC质量分数和不同的熔融状态下,用真空高频感应熔覆法制得Ni60-WC复合涂层,分析复合涂层的化学成分和组织形貌,研究WC质量分数和熔融状态对高频感应熔覆Ni60-WC复合涂层耐蚀性的影响。结果表明:复合涂层具有优良的耐蚀性能,其中在盐酸(质量分数10%)中最大耐蚀性是Q235-A的100倍左右,在硫酸(质量分数10%)中最大耐蚀性是Q235-A的20倍左右。在同种腐蚀溶液中的复合涂层材料耐蚀性一般随着WC质量分数的增加而降低。刚熔状态比过熔状态耐蚀性能要好,这是由于合金粉末中含有耐腐蚀元素Ni、Cr等,提高了涂层的耐蚀性。但随着熔烧时间的延长,涂层与基体之间产生扩散,涂层中Fe元素质量分数增加,腐蚀元素Ni、Cr的质量分数相对减少,导致涂层的耐蚀性降低。

Corrosion Resistance of Vacuum High-frequency Induction Cladding Ni60-WC Composite Coating

In the case of different contents of tungsten carbide and different cases of a molten state, Ni60-WC composite coatings were prepared by vacuum high frequency induction cladding technology, and the chemical composition and morphology of the composite coatings were analyzed. The influence of WC content and molten state on the corrosion resistance of highfrequency induction cladding Ni60WC composite coating were researched. The results show that the composite coatings present excellent corrosion resistance, which is about 100 times of Q235A in 10% HCl corrosive liquid and about 20 times in 10% H2SO4 liquid. Corrosion resistance of composite coating materials generally increases with the addition of reduced content of WC in the same etching solution. The just melt state is better than the molten state, because of Ni, Cr and other corrosionresistant elements in alloy powder. However, with the increase of the melting time and the spread between the coating and the substrate, Fe content in the coating increases, and Ni, Cr content decreases, resulting in the reduce of corrosion resistance of the coatings.