Comparison of Corrosion Resistance of Nickel Saving Stainless Steels

The corrosion resistance of 200 series austenitic stainless steels,304 stainless steel and 400 series ferritic stainless steels was studied by means of potentiodynamic polarization curves in 3.5% NaCl solution and salt spray testing.Results showed that 400 series ferritic stainless steels were better than 200 series austenitic stainless steels,304 stainless steel was the best one for pitting corrosion resistance,200 series austenitic stainless steels were the worst and 443 stainless steel was close to 304 stainless steel and 439 stainless steel was worse than 304 stainless steel for uniform corrosion resistance.The pitting potential of 201,202,304,439 and 443 stainless steel in 3.5% NaCl solution was -32 mV,-22 mV,312 mV,165 mV,and 227 mV(SCE) and the corrosion rate was 0.0071 mm/a,0.0062 mm/a,0.0026 mm/a,0.0038 mm/a and 0.0024 mm/a,respectively.