| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-strength hot-dip galvanized steel sheet having excellent formability and its manufacturing method. SOLUTION: The steel sheet has a composition containing, by mass, 0.13 to 0.30% C, <0.2% Si, 0.8 to 2.8% Mn,≤0.03% P,≤0.03% S, 0.25 to 1.80% Al, 0.05 to 0.30% Mo and≤0.010% N and also has a metallic structure composed mainly of ferrite or bainite and containing≥5% retained austenite. Moreover, ferrite structure is 15 to 70% by volume fraction and average ferrite grain size is 10 to 20μm. Further, pearlite structure is≤5% by volume fraction and average pearlite grain size is≤3μm. COPYRIGHT: (C)2007,JPO&INPIT
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