Abstract: The crevice corrosion performance of 445M ferrite stainless steel ( % ： 0. 004 ~0. 005C, 22. 4 - 22. 29Cr, 1. 10 ~ 1. 65Mo, 0. 015 ~0. 016P, 0. 003 ~0. 004S, 0. 012 -0. 016N, 0. 22 - 0. 38Ti) and 316L austenite stainless steel ( % ： 0. 022C, 16. 80Cr, 10. 19Ni, 2. 02Mo, 0. 025P, 0. 001S, 0. 046N) in sodium chloride solution with chlorion concentration (250 - 5 000) x 10^-6 at 40 ~ 60 ℃ has been studied. Results show that the crevice corrosion resistance of 445M steel is better than that of 316L steel ； and with increasing the Mo content in 445M steel from 1. 10% to 1. 65% , the crevice corrosion resistance of steel obviously increases, it indicated that the pitting corrosion resistance equivalent- Cr +3. 3Mo is an important index to measure the pitting and crevice corrosion resistance of stainless steels.

Key words: 445M Ferrite Stainless Steel, Crevice Corrosion, Pitting Corrosion Resistance Equivalent

摘要： 研究了445M铁素体不锈钢(%:0.004～0.005C、22.24～22.29Cr、1.10～1.65Mo、0.015～0.016P、0.003～0.004S、0.012～0.016N、0.22～0.38Ti)和316L奥氏体不锈钢(%:0.022C、16.80Cr、10.19Ni、2.02Mo、0.025P、0.001S、0.046N)在40～60℃氯离子浓度(250～5 000)×10^-6的氯化钠溶液的缝隙腐蚀性能。结果表明,445M铁素体不锈钢的耐缝隙腐蚀性能优于316L奥氏体不锈钢;当445M钢中的Mo含量由1.10%提高至1.65%时,钢的耐缝隙腐蚀性能明显提高,表明点蚀当量Cr+3.3Mo是衡量不锈钢耐点蚀和耐缝隙腐蚀的重要指标。

关键词: 445M铁素体不锈钢, 缝隙腐蚀, 点蚀当量