High-strength steel sheet and method for manufacturing the same

A high-strength steel sheet having

• a chemical composition containing, by mass %, C:
• 0.070% to 0.100%, Si:
• 0.30% to 0.70%, Mn:
• 2.20% to 2.80%, P:
• 0.025% or less, S:
• 0.0020% or less, Al:
• 0.020% to 0.060%, N:
• 0.0050% or less, Nb:
• 0.010% to 0.060%, Ti:
• 0.010% to 0.030%, B:
• 0.0005% to 0.0030%, Ca:
• 0.0015% or less, and the balance being Fe and inevitable impurities;
• a microstructure including, in terms of area ratio, 30% or more of a ferrite phase, 40% to 65% of a bainite phase and/or a martensite phase, and 5% or less of cementite,
• wherein, in a surface layer that is a region within 50 μm from the surface in the thickness direction, the area ratio of a ferrite phase is 40% to 55% and the total area ratio of a bainite phase having a grain diameter of more than 5 μm and/or a martensite phase having a grain diameter of more than 5 μm is 20% or less;
• and
• a tensile strength being 980 MPa or more.