Effects of Cold Rolling on the Corrosion Resistance of 2205 Duplex Stainless Steel in Artificial Seawater

Abstract

In order to clarify the change of the corrosion properties of 2205 duplex stainless steel in artificial seawater after cold rolling，2205 duplex stainless steel was cold-rolled at different reduction rates (PCRR ＝20%-80%)，and then the sample was studied by metallographic observation and hardness measurement.The corrosion resistance of cold-rolled 2205 duplex stainless steel in artificial seawater (3.5%NaCl)was investigated using dynamic potential polarization curve and electrochemical impedance spectroscopy.Results showed that the hardness and corrosion resistance of 2205 stainless steel presented non-monotonic variation with the increase of PCRR.In the interval from 0 to 40%，the corrosion resistance and hardness increased with the increase of the reduction rate，and the self-corrosion potential increased from -309 mV to-269 mV.In the interval from 40%to 80%，the corrosion resistance decreased with the increase of the reduction rate，and the self-corrosion potential decreased from -269 mV to -322 mV.Moreover，the corrosion resistance was highest at the reduction rate of 40%，and the Brinell hardness of the sample with the reduction rate of 60%was the highest，about 374 HBW.Suitable cold rolling could result in high-density dislocation and structure refinement，which was beneficial to the corrosion resistance of 2205 duplex stainless steel.However，an excessive reduction rate would result in the precipitation of σ-phase which was detrimental to corrosion resistance.

Keywords

• 2205 duplex stainless steel|cold rolling reduction rate|artificial seawater|corrosion