Study on Corrosion Behavior of AISI316L and SAF2205 Stainless Steels in Acetic Acid Solution Containing Br-Ion

Petrochemical equipments made of austenitic stainless steel are often used in the environment of acetic acid solution. Premature corrosion failure led by acetic acid solution containing Cl⁻ or Br⁻ occurs in service. In the present paper, corrosion behavior of AISI316L austenitic stainless steel and SAF2205 duplex stainless steel in acetic acid solution containing Br-ion was studied by measuring the corrosion weight loss and Potentiodynamic anodic polarization curve. Effects of temperature and Br⁻ concentration on the corrosion behaviors of AISI316L and SAF2205 material were investigated. The research results show that the corrosion rate markedly increases and pitting potential rapidly decreases with increasing temperature and Br⁻ ion concentration. The pitting resistance of SAF2205 stainless steels is superior to AISI316L. For sensitized AISI316L and SAF2205 stainless steels, the similar rules were founded with increasing Br⁻ concentration; sensitizing treatment will lead to decrease in corrosion resistance. Pitting induced by Br ion preferentially occurred at austenitic boundaries for sensitized AISI316L stainless steels, whereas pitting preferentially occurred at austenitic boundaries, ferrite-austenite boundaries and ferrite boundaries for sensitized SAF2205 duplex stainless steels.