Steel sheet and manufacturing method of therefor

A steel sheet comprising, as a chemical composition, by mass %:

• C:
• 0.050% to 0.500%;
• Si:
• 0.01% to 3.00%;
• Mn:
• 0.50% to 5.00%;
• P:
• 0.0001% to 0.1000%;
• S:
• 0.0001% to 0.0100%;
• Al:
• 0.001% to 2.500%;
• N:
• 0.0001% to 0.0100%;
• O:
• 0.0001% to 0.0100%;
• Ti:
• 0% to 0.300%;
• V:
• 0% to 1.00%;
• Nb:
• 0% to 0.100%;
• Cr:
• 0% to 2.00%;
• Ni:
• 0% to 2.00%;
• Cu:
• 00% to 2.00%;
• Co:
• 0% to 2.00%;
• Mo 0% to 1.00%;
• W:
• 0% to 1.00%;
• B:
• 0% to 0.0100%;
• Sn:
• 0% to 1.00%;
• Sb:
• 0% to 1.00%;
• Ca:
• 0% to 0.0100%;
• Mg:
• 0% to 0.0100%;
• Ce:
• 0% to 0.0100%;
• Zr:
• 0% to 0.0100%;
• La:
• 0% to 0.0100%;
• Hf:
• 0% to 0.0100%;
• Bi:
• 0% to 0.0100%;
• REM:
• 0% to 0.0100%;
• and
• a remainder including Fe and impurities,
• wherein a steel structure in a ⅛ to ⅜ thickness range centered on a ¼ thickness position from a surface contains, by volume fraction,
• a soft ferrite:
• 0% to 30%,
• a retained austenite:
• 3% to 40%,
• a fresh martensite:
• 0% to 30%,
• a sum of pearlite and cementite:
• 0% to 10%, and
• a remainder includes hard ferrite,
• in the ⅛ to ⅜ thickness range, a number proportion of the retained austenite having an aspect ratio of 2.0 or more in the total retained austenite is 50% or more,
• wherein a region having a hardness of 80% or less in the ⅛ to ⅜ thickness range is defined as a soft layer, the soft layer having a thickness of 1 to 100 μm from the surface in a sheet thickness direction is present,
• in ferrite contained in the soft layer, a volume fraction of grains having an aspect ratio of less than 3.0 is 50% or more,
• a volume fraction of retained austenite in the soft layer is less than 50% of the volume fraction of the retained austenite in the ⅛ to ⅜ thickness range, and
• when an emission intensity at a wavelength indicating Si is analyzed in the sheet thickness direction from the surface by a radio-frequency glow discharge analysis method, a peak of the emission intensity at the wavelength indicating Si appears in a range of more than 0.2 μm and 5.0 μm or less from the surface.