Acta Metallurgica Sinica (English Letters) ›› 2015, Vol. 28 ›› Issue (9): 1089-1096.DOI: 10.1007/s40195-015-0299-4

• Orginal Article • Previous Articles     Next Articles

Effect of Alloying Tin on the Corrosion Characteristics of Austenitic Stainless Steel in Sulfuric Acid and Sodium Chloride Solutions

Min Sun1, Ming Luo2, Chao Lu2, Tian-Wei Liu3, Yan-Ping Wu3, Lai-Zhu Jiang2, Jin Li1()   

  1. 1 Department of Materials Science, Fudan University, Shanghai 200433, China
    2 Research and Development Center, Baosteel Co., Ltd., Shanghai 201900, China
    3 Science and Technology on Surface Physics and Chemistry Laboratory, P. O. Box 718-35, Mianyang 621907, China
  • Received:2015-01-30 Revised:2015-05-14 Online:2015-08-15 Published:2015-09-20

Abstract:

The effect of tin on general and pitting corrosion behaviors of the austenitic stainless steel in sulfuric acid and sodium chloride solutions was investigated by potentiostatic critical pitting temperature, cyclic potentiodynamic polarization, electrochemical impedance spectroscopy, and scanning electron microscopy. The results showed that there is an optimal tin addition which is around (0.062-0.1) wt%, and the general corrosion resistance of B316LX with 0.08 wt% tin addition in boiling H2SO4 increased remarkably with a corrosion rate of an order of magnitude lower than that of 316L. Hydrolyzation of tin ions induces more metastable pit occurrence on the material surface. However, the pitting resistance of B316LX increases because tin oxides improve the density and uniformity of the passive film, and hydroxide and oxide of tin inhabit the process of pit growing. The effect of tin on pitting corrosion process is illustrated schematically.

Key words: Stainless steel, Corrosion resistance, Passivation, Pitting corrosion