衣康酸介质中杂质离子对两种不锈钢腐蚀行为的影响

针对发酵法生产衣康酸过程中的腐蚀问题研究了两种不锈钢在衣康酸工况介质（发酵液）中的腐蚀行为，探讨了介质中杂质离子Ｃｌ－、Ｆｅ３＋、ＳＯ２－４等对腐蚀的影响。结果表明，随衣康酸介质中Ｃｌ－含量增加，不锈钢的腐蚀速率也增大，而其点蚀电位则随Ｃｌ－浓度的对数值增加呈线性下降；Ｆｅ３＋浓度的增大可使不锈钢／发酵液由活化体系转变成活化 钝化体系；ＳＯ２－４对不锈钢稍有缓蚀作用；在含杂质的衣康酸介质中，Ｒ１双相不锈钢的耐全面腐蚀和耐点蚀性显著优于３１６Ｌ奥氏体不锈钢。

Influence of ionic impurities in itaconic acid medium on corrosion behaviour of two kinds of stainless steel.

The corrosion behaviour of two kinds of stainless steel in itaconic acid medium(fermentative liquid)was studied based on the corrosion in the production of itaconic acid using the fementative method,the influence of the ionic impurities,such as Cl-,Fe3+,and SO2-4 in itaconic acid medium on the corrosion of the two kinds of the stainless steel was discussed.The result shows that the corrosion rate of the stainless steel would become higher with the increase of Cl- in itaconic acid medium,and the pitting potential would lower linearly with the increase of the logarithmic value of Cl- concentration;the stainless steel/fermentative liquid would change from the active system to the active passive system for the increase of Fe3+ concentration;SO2-4 had an inhibitive effect on the stainless steel;the total corrosion resistance and pitting resistance of the R1 stainless steel were better than those of 316L stainless steel in the itaconic acid medium with impurities.