Patent ID: 7767038

Claim:
A low-nickel austenitic stainless steel, comprising by weight: C ≦about 0.08%; Mn about 4.0~5.0%; Si about 0.7~1.0%; Ni about 3.5~4.5%; Cr about 16.0~18.0%; Cu about 3.0~3.50%; S ≦about 0.045%; P ≦about 0.030%; impurity elements in a total amount of ≦about 0.2%; and Fe balance. wherein the yield strength of the low-nickel austenitic stainless steel is ≧300 MPa; the tensile strength of the low-nickel austenitic stainless steel is ≧700 MPa; the ductility of the low-nickel austenitic stainless steel is of ≧55%; and the hardness of the low-nickel austenitic stainless steel is of ≦210, and wherein the stainless steel has been thermally treated after casting by solution treatment followed by tempering.