Corrosion Characteristics of Molybdenum-Modified Type 13%Cr4%Ni Steels

Abstract

The addition of molybdenum at a concentration of about 0·50% to steels of the type 13%Cr4%Ni eliminates the susceptibility to temper embrittlement. The molybdenum addition improves the corrosion resistance of the type of steel investigated, but an addition of about 0·50% molybdenum only partially supresses the susceptibility to interCrystaliine corrosion. An increased addition of molybdenum (1·48%) does not lead to increased toughness values, but distinctly improves the corrosion resistance and eliminates the susceptibility to intercrystalline corrosion. The modified potentiostatic polarisation method employed enables one to evaluate the corrosion resistance and sensitivity to intercrystalline corrosion, and possibly also to assess the extent of the austenite formation after tempering in the intercritical temperature range (steels B and C).