Corrosion Resistance on High Strength Bainitic Steel and 09CuPCrNi After Wet-Dry Cyclic Conditions

• Published in: Journal of iron and steel research, international international, 2013-02, Vol.20 (2), p.72-78
• Main Authors: WANG, Zhi-fen, YIN, Fu-xing, WU, Li-xin, SUN, Yi-qiang, ZHANG, Wan-lin
• Format: Article
• Language: English
• Subjects: 09CuPCrNi; Applied and Technical Physics; Bainitic steel; Chromium; Corrosion resistance; Corrosion resistant steels; Engineering; Enrichment; Fe3O4; FeOOH; High strength; high strength bainitic steel; Iron and steel industry; Machines; Manufacturing; Materials Engineering; Materials Science; Metallic Materials; Physical Chemistry; Processes; rust layer; Rusting; Steels; 加速腐蚀试验; 干湿循环; 循环条件; 耐腐蚀性; 贝氏体钢; 高强度
• ISSN: 1006-706X; 2210-3988
• DOI: 10.1016/S1006-706X(13)60060-6

The accelerated wet-dry cyclic corrosion tests have been carried out of a high strength bainitic steel and 09CuPCrNi. The results indicated that the corrosion resistance of 09CuPCrNi was better than that of the bainitic steel based on the mass loss measurements. The morphology and composition of the rusting products have been investigated in order to realize the mechanism of rust formation on the two steels. The rust scale on both steels was composed of a dense inner layer and a loose outer layer. The inner layer grew thicker and denser as the test proceeding. Both of inner and outer layers were mainly composed of magnetite （Fe3O4） and maghemite （γ-Fe2O3） with a small amount of lepidocrocite （γ-FeOOH） and akaganeite （β-FeOOH）. The rust phase of γ-Fe2O3 was detected in a higher amount of the inner layer, resulting in a much denser inner layer. The inner rust layer of 09CuPCrNi being denser and thicker than that of the high strength bainitic steel was attributed to the alloying elements such as copper, chromium and phosphorus enriched in it. The protective inner rust layer plays an important role in the corrosion resistance of the steel.