| 摘要 |
<p>Provided is a high-strength hot-dip galvanized steel sheet having excellent workability, namely, excellent ductility and hole expansion formability, and high yield ratio. The steel sheet has a chemical composition containing by mass %: C: 0.05-0.15 %; Si: 0.10-0.90 %; Mn: 1.0-1.9 %; P: 0.005-0.10 %; S: 0.0050 % or less; Al: 0.01-0.10 %; N: 0.0050 % or less; Nb: 0.010-0.100 %; and the balance being Fe and incidental impurities, in which: the steel sheet has a complex phase that includes: ferrite having an average crystal grain size of 15 µm or less to at least 90 % in volume fraction; martensite having an average crystal grain size of 3.0 µm or less to 0.5 % or more and less than 5.0 % in volume fraction; pearlite to 5.0 % or less in volume fraction; and the balance being a phase generated at low temperature.</p> |
