(PS11044) Metastable duplex stainless steels having high ductility, high strength and high resistance to stress corrosion cracking

摘要

For improving the ductility of duplex stainless steels, new metastble duplex stainless steels were experimentally developed. These new steels are characterized by low content of nickel and high content of nitrogen and manganese, e.g. 20.2%Cr-1.0%Mo-3.0%Mn-2.1%Ni-0.14%N. By optimizing the amount of strain-induced martensite during deformation, total elongation is successfully improved to the level of Type304, i.e. austenitic stainless steel with 18%Cr-8%Ni. 0.2% proof stress and tensile strength of these new steels are higher than those of Type304. Pitting corrosion resistance of these new steels is equivalent to that of Type 304. These new steels exhibit extremely high resistance to stress corrosion cracking as compared to Type304. In addition to these beneficial properties, the low content of nickel means that the cost of raw material is hardly subject to the high and variable market price of nickel.