Austenite stainless steel sheet, method for producing same, and sheet spring

An austenitic stainless steel sheet,

• wherein the austenitic stainless steel sheet comprises, on a mass basis, C:
• 0.04 to 0.11%, Si:
• 2.0 to 3.5%, Mn:
• 1.50% or less, Ni:
• 6.0 to 10.0%, Cr:
• 12.0 to 15.0%, Mo:
• 1.3 to 3.2%, Cu:
• 1.00% or less, N:
• 0.03 to 0.15%, and O:
• 0.0050% or less, the balance being Fe and impurities;
• wherein the austenitic stainless steel sheet has a value of Md30 of −30.0 to 0° C., wherein the value of Md30 is represented by the following equation (1):
• Md
• 3
• ⁢
• 0
• =
• 551
• -
• 462
• ⁢
• (
• C
• +
• N
• )
• -
• 9.2
• Si
• -
• 8.1
• Mn
• -
• 29
• ⁢
• (
• Ni
• +
• Cu
• )
• -
• 13.7
• Cr
• -
• 18.5
• Mo
• (
• 1
• )
• in which the symbols of the elements each represents a content in % by mass of each element;
• wherein the austenitic stainless steel sheet has a metallographic structure having a content of a strain-induced martensite phase of 30% by volume or more;
• and
• wherein the austenitic stainless steel sheet has a thickness of 0.15 mm or less,
• wherein the austenitic stainless steel sheet has a tensile strength (TS) of 2200 MPa or more,
• wherein the austenitic stainless steel sheet has a fold number of 1100 or more, as measured in accordance with JIS P 8115:2001.