Stainless steel foil
The present invention provide a ferritic stainless steel foil having a high thickness precision even with a thickness 60 μm or less ultrathin stainless steel foil and simultaneously having a plastic deformation ability and good elongation at break, that is, having a good press-formability (deep drawing ability). The present invention is a stainless steel foil having a thickness of 5 μm to 60 μm, wherein a recrystallization ratio of said stainless steel foil is 90% to 100%, a surface layer of said stainless steel foil has a nitrogen concentration of 1.0 mass % or less, three or more crystal grains are contained in the thickness direction of said stainless steel foil, an average crystal grain diameter “d” of said crystal grains is 1 μm to 10 μm, and, when said thickness is “t” (μm), an area ratio of crystal grains having a crystal grain diameter of t/3 (μm) or more is 20% or less.
1. A stainless steel foil having a thickness of 5 μm to 60 μm, wherein a recrystallization ratio of said stainless steel foil is 90% to 100%,
a surface layer of said stainless steel foil has a nitrogen concentration of 1.0 mass % or less,
three or more crystal grains are contained in the thickness direction of said stainless steel foil, an average crystal grain diameter “d” of said crystal grains is 1 μm to 10 μm, and,
when said thickness is “t” (μm), an area ratio of crystal grains having a crystal grain diameter of t/3 (μm) or more is 20% or less,
wherein the area ratio is calculated by measuring the average crystal grain diameter of the crystal grains present in a predetermined measurement field at the surface of the stainless steel foil based on JIS G 0551, and dividing the measured crystal grains having a crystal grain diameter of t/3 (μm) or more from the measured crystal grains having a crystal grain diameter of less than t/3 (μm) to calculate the ratio of the measured crystal grains having a crystal grain diameter of t/3 (μm) or more in the area of the measurement field.
2. The stainless steel foil according to claim 1 , wherein said thickness is 5 μm to 25 μm.
3. The stainless steel foil according to claim 1 , wherein a surface roughness Rz is 100 nm or more, and 1/10 or less of the thickness.
4. The stainless steel foil according to claim 1 , wherein an elongation at break is 10% or more.
5. The stainless steel foil according to claim 1 , wherein said stainless steel foil is ferritic stainless steel foil.
6. The stainless steel foil according to claim 1 , wherein said stainless steel foil is austenitic stainless steel foil.
7. The stainless steel foil according to claim 1 , wherein a resin film is laminated on at least one surface of said stainless steel foil.
8. The stainless steel foil according to claim 2 , wherein a surface roughness Rz is 100 nm or more, and 1/10 or less of the thickness.
9. The stainless steel foil according to claim 2 , wherein an elongation at break is 10% or more.
10. The stainless steel foil according to claim 3 , wherein an elongation at break is 10% or more.
11. The stainless steel foil according to claim 2 , wherein said stainless steel foil is ferritic stainless steel foil.
12. The stainless steel foil according to claim 3 , wherein said stainless steel foil is ferritic stainless steel foil.
13. The stainless steel foil according to claim 4 , wherein said stainless steel foil is ferritic stainless steel foil.
14. The stainless steel foil according to claim 2 , wherein said stainless steel foil is austenitic stainless steel foil.
15. The stainless steel foil according to claim 3 , wherein said stainless steel foil is austenitic stainless steel foil.
16. The stainless steel foil according to claim 4 , wherein said stainless steel foil is austenitic stainless steel foil.
17. The stainless steel foil according to claim 2 , wherein a resin film is laminated on at least one surface of said stainless steel foil.
18. The stainless steel foil according to claim 3 , wherein a resin film is laminated on at least one surface of said stainless steel foil.
19. The stainless steel foil according to claim 4 , wherein a resin film is laminated on at least one surface of said stainless steel foil.
20. The stainless steel foil according to claim 5 , wherein a resin film is laminated on at least one surface of said stainless steel foil.