| 摘要 |
PROBLEM TO BE SOLVED: To provide a high strength hot-dip galvanized steel sheet which is not fractured in the HAZ (heat affected zone) of the weld zone on forming and has formability similar to that of a single sheet. SOLUTION: The high strength hot-dip galvanized steel sheet contains, as chemical components, 0.04 to 0.25% C,≤0.7% Si, 1.4 to 3.5% Mn, 0.05 to 1% Cr,≤0.05% P,≤0.01% S and 0.005 to 0.1% Nb, and the balance substantially Fe with inevitable impurities. The steel sheet also has a composite structure consisting of ferrite and a low temperature transformation phase having a mean grain size of≤10μm. The steel sheet can contain one or more elements selected from 0.05 to 1% Mo, 0.02 to 0.5% V, 0.005 to 0.05% Ti and 0.0002 to 0.002% B as well. COPYRIGHT: (C)2008,JPO&INPIT
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