High-strength steel sheet and method for manufacturing same

A high-strength steel sheet comprising a steel sheet,

• the steel sheet having:
• a component composition containing
• C in an amount of 0.090 mass % or more and 0.390 mass % or less,
• Si in an amount of 0.01 mass % or more and 2.00 mass % or less,
• Mn in an amount of 2.00 mass % or more and 4.00 mass % or less,
• P in an amount of 0.100 mass % or less,
• S in an amount of 0.0200 mass % or less,
• Al in an amount of 1.000 mass % or less,
• N in an amount of 0.0100 mass % or less, and
• O in an amount of 0.0100 mass % or less, with a remaining part containing Fe and inevitable impurities;
• and a microstructure,
• wherein in the microstructure,
• an area ratio of martensite is 70% or more,
• an area ratio of ferrite is 10% or less,
• an area ratio of retained austenite is 10% or less, and
• a proportion of the number of martensite blocks in which metastable carbides are present to the number of martensite blocks is 2% or more.