Austenite stainless steel material, method for producing same, and plate spring

A method for producing an austenitic stainless steel material, the method comprising:

• subjecting a rolled material to a solution treatment, followed by cold rolling at a rolling reduction ratio to obtain a dislocation density of a strain-induced martensite phase of 8.0×1016 m−2 or less, a dislocation density of a retained austenite phase of 1.5×1016 to 6.0×1016 m−2, and a content of the strain-induced martensite phase of 20 to 55% by volume, wherein the rolled material comprises, on a mass basis, 0.200% or less of C, 4.00% or less of Si, 5.00% or less of Mn, 4.00 to 10.00% of Ni, 12.00 to 18.00% of Cr, 3.50% or less of Cu, 1.00 to 5.00% of Mo, and 0.200% or less of N, a total amount of C and N being 0.100% or more, and the balance being Fe and impurities, and wherein the rolled material has a value of Md30 of −40.0 to 0° C., the value of Md30 being represented by the following equation (1):
• Md30=551−462(C+N)−9.2Si−8.1Mn−29(Ni+Cu)−13.7Cr−18.5Mo (1)
• in which the symbols of the elements each represents a content (% by mass) of each element.

(canceled)