Effect of Tensile Elastic Stress on Pitting Corrosion Behavior of 2205 Duplex Stainless Steel in Nacl Solution Containing Sulfide Ions

Abstract

The effect of elastic stress on pitting corrosion behavior of 2205 duplex stainless steel in NaCl solution containing sulfide ions is investigated. As the elastic tensile stress increasing, the pitting corrosion sensitivity of 2205 DSS decrease in the first and then gradually increase, which is due to the chemical states, thickness and micro-defects of passive film. Furthermore, the initial pits occur at austenite phase under low elastic stress but at ferrite phase under higher elastic stresses. The growth of initialed corrosion pits towards the stress concentration direction, along the pit bottom direction and the vertical direction of tensile stress.

Keywords: Duplex stainless steel, Elastic tensile stress, Passive film, pitting corrosion