合金元素对铸造Fe-Cr铁素体不锈钢耐浓硫酸腐蚀性能的影响

摘要

采用电化学技术、浸泡腐蚀及能谱分析等研究了合金元素对铸造Fe-Cr铁素体不锈钢耐浓硫酸腐蚀行为的影响.结果表明:随铬含量的增加,Fe-Cr合金的耐浓硫酸腐蚀性能增强,单一的铬合金化不能使Fe-Cr合金在60℃,98％ H2SO4中自钝化;钼能促进Fe-Cr25-Mo合金的钝化和自钝化,随钼含量的增加,Fe-Cr25-Mo合金的耐浓硫酸腐蚀性能增强;辅助合金元素镍、铜可促进Fe-Cr25Mo2合金的钝化和自钝化,而钛、铌的影响不大.%The effects of alloying elements on the corrosion behavior of foundry Fe-Cr ferritic stainless steels in concentrated sulfuric acid were studied by electrochemical techniques,immersion corrosion and energy dispersive spectroscopy (EDS).The results show that the corrosion resistance of Fe-Cr alloys in concentrated sulfuric acid improved with the increase of Cr content.However,the single Cr alloyed Fe-Cr alloy was unable to reach selfpassivation in 98％ H2SO4 at 60 ℃.Mo addition enhanced the corrosion resistance and promoted the passivation and self-passivaiton of Fe-Cr25-Mo alloys.Elements Ni and Cu can also promoted the passivation and self-passivation of Fe-Cr25Mo2 alloys,whereas Ti and Nb only had a little influence on the passivation.