(PS11025) The Effect of Manganese on the Corrosion Resistance of Hercules B Alloy (A Low Nickel Austenitic Stainless Steel)

摘要

Austenitic stainless steels have useful engineering properties such as high formability, ductility, toughness, good weldability and corrosion resistance. However, for structural applications, their cost per unit strength is high, compared to conventional structural materials such as carbon steels. The high cost of austenitic stainless steels is due to their high nickel content (~ 8 wt.%). By increasing the nitrogen (N) and reducing the nickel (Ni) content of austenitic stainless steels, a more cost effective alloy, Hercules~(TM) has been developed by Mintek. Hercules~(TM) has a base composition of 9 wt.% Mn, 0.05 wt.% C, 2 wt.% Ni, 0.25 wt.% N and 16.5 wt.% Cr. Its target market is the construction industry. It has good mechanical properties with a tensile strength of ~850 MPa and hardness of ~260 Hv. Its corrosion resistance, however, is poorer than commercial austenitic stainless steels such as AISI 201 and AISI 304. Varying additions of manganese (Mn) and molybdenum (Mo) were made to Hercules~(TM) to determine their effects on the corrosion resistance. This paper discusses the work done in determining the effects of manganese on the corrosion behaviour of modified Hercules~(TM).10 wt.% Mn and 0.5 wt.% Mo were determined to be optimum additions for a cost-effective corrosion resistant Hercules~(TM) alloy.