碳钢渗Ti及氮化在硝酸中的耐腐蚀性研究

Research on Corrosion Resistance of Carbon Steel After Infiltrated Ti and Plasma Nitriding in HNO_3 Solution

在碳钢表面实施等离子渗Ti,然后进行离子氮化。将处理试样在1 mol/L HNO3溶液中用PS-268A型电化学测量仪进行耐腐蚀实验,并采用SEM对腐蚀试样表面进行分析。结果表明:在1 mol/L HNO3酸性溶液中,渗Ti、渗Ti+离子氮化试样的致钝电位较未处理碳钢试样明显降低,钝化电位区间分别比未处理碳钢提高3.17倍和2.96倍,试样耐腐蚀性能分别比未处理试样提高7.44倍和4.54倍;腐蚀机理为:未处理碳钢腐蚀后表面形貌表现为较大的腐蚀坑且凸凹和起伏较明显,是典型的孔蚀;渗Ti试样为轻微面腐蚀;渗Ti+离子氮化试样腐蚀机理表现为典型的晶间腐蚀。

Plasma infiltra Ti then plasma nitridizing on the surface of carbon steel was carried out.Corrosion experiment of treated sample in 1 mol/L HNO3 solution was carried out using PS-268A electrochemical measuring instrument.And the surface morphology of corrosion sample was analyzed using SEM and EDS.The results show that： in 1 mol/L HNO3 solution,the passivation potential of Ti alloy layer and TiN layer significantly decreases compared with the untreated sample,the precipitation of TiN layer and Ti alloy layer is enhanced by 2.96 times and 3.17 times;the corrosion resistance of TiN layer and Ti alloy layer is enhanced by 4.54 times and 7.44 times.The corrosion mechanisms of untreated carbon steel,Ti alloy layer and TiN layer are pitted,light aspect corrosion and intergranular corrosion,respectively.