| 摘要 |
A high-strength steel sheet comprises a metallic structure consisting of a ferrite phase and a hard second phase dispersed in the ferrite phase, the hard second phase in the metallic structure having an area ratio of 30 to 70%, and the ferrite of which grain sizes are not more than 1.2 mum having an area ratio of 15 to 90% in the ferrite phase. The term ds is an average grain size of the ferrite of which grain sizes are not more than 1.2 mum, the term dL is an average grain size of ferrite of which grain sizes are more than 1.2 mum, and the ds and the dL satisfy the following equation (1): <?in-line-formulae description="In-line Formulae" end="lead"?>dL/ds>=3 (1).<?in-line-formulae description="In-line Formulae" end="tail"?>
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