The Variable Corrosion Resistance of 18CR-8NI Stainless Steels: I. Behavior of Commercial Alloys

摘要

The electrochemical and corrosion characteristics of Types 303, 304 and 316 stainless steel in 1N H2SO4 were determined using precision potentiostatic polarization and conventional coupon exposure/weight change techniques. Factors increasing the magnitude of the critical anodic current density, Ic, are shown to have a deleterious effect on the passivating tendencies of Type 304 alloys. Statistical analysis of the electrochemical properties of Type 304 alloy has shown that Ic is related to chemical constitution by the following relationship: Ic = 15471 + 373 (Mn) - 1240 (Cu) - 750 (Mo) + 76000 (S) - 6500 (C) - 840 (Cr). Control of the detrimental effects of sulphur and manganese in Type 304 alloys can be obtained during manufacture by increase in copper and molybdenum content. (Author)