Warm working method for stainless steel foil and mold for warm working

A mold for warm working a stainless steel foil,

• the mold comprising:
• a punch;
• a blank holder disposed at an outer circumferential position of the punch;
• and
• a die disposed to face the blank holder, and where
• the mold serving to subject an austenitic stainless steel foil with a thickness equal to or less than 300 μm to drawing by pressing the stainless steel foil together with the punch inward of the die in a state in which the stainless steel foil is interposed between the blank holder and the die, wherein
• the punch is provided with cooling means,
• the blank holder and the die are provided with heating means, and
• the stainless steel foil is subjected to drawing in a state in which an annular region of the stainless steel foil that is in contact with a shoulder portion of the punch is set to a temperature equal up to 30° C. and an external region outside the annular region interposed between the blank holder and the die is set to a temperature of from 40° C. to 100° C.,
• wherein a thermally insulating member is provided at an inner circumferential portion of the blank holder facing the outer circumferential surface of the punch.

A warm working method for an austenitic stainless steel foil, the method comprising:

• disposing the austenitic stainless steel foil with a thickness equal to or less than 300 μm to face a punch,
• subjecting the austenitic stainless steel foil to a draw, wherein an annular region of the austenitic stainless steel foil that is in contact with a shoulder portion of the punch is set to a temperature up to 30° C. and an external region of the austenitic stainless steel foil that is outside the annular region is set to a temperature of from 40° C. to 100° C.,
• restricting the external region by using a blank holder disposed at an outer circumferential position of the punch when the austenitic stainless steel foil is subjected to the draw, and
• wherein a heater for heating the external region is provided inside the blank holder, and a thermally insulating member provided at an inner circumferential portion of the blank holder facing the outer circumferential surface of the punch.