The Effect of Silicon on the Stress Corrosion Resistance of Low Alloy High Strength Steels

Abstract

Abstract The effect of five levels of silicon, within the range 0.09% to 2.15%, on the stress corrosion resistance of 4340 steel was established in 3.5% sodium chloride solution for two tensile strength ranges (280 to 300 ksi and 230 to 240 ksi). At the higher strength range, the threshold stress intensity KISCC was independent of silicon content, but the stress corrosion crack velocity was significantly retarded when the silicon content exceeded 1.5%. At the 230 to 240 ksi strength range, steels containing less than 1.5% silicon exhibited a higher KIscc threshold than steels of higher silicon content. Strength level had a significant effect on crack velocity characteristics.