Abstract
The effects of Ti in 13Cr stainless steels containing only about 0.01% C and N upon the corrosion resistance and the properties of passivation and passive state, were investigated in comparison with the commercially produced AISI type 410 and 430 stainless steels.
The experimental results showed that, by the addition of about 0.3% Ti, 13Cr stainless steels containing about 0.01% C and N were superior to AISI type 430 stainless steel in general corrosion resistance. The improvement of corrosion resistance by the addition of Ti was attributable to the decrease of the critical anodic current density and to the shift of the potential to less noble direction. It was confirmed that this beneficial effect was brought by Ti as solid solution. With regard to the properties of passive film, it was concluded that the decrease of C and N to 0.01% level in ferrific stainless steels led to the increase of the quantity of coulomb for reduction of passive film and that the addition of Ti at solid solution state resulted in an improvement effect on the passive film in quality, consequently 13Cr stainless steels containing Ti and extremely low C and N showed higher stability in passivity than commercially melted AISI type 430 stainless steel.
