Hot-dip galvannealed steel sheet
AssigneeJfe Steel Corporation
InventorsHideki Nagano, Daisuke Harako, Yuji Tanaka
Life of this patent
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Abstract
A hot-dip galvannealed steel sheet has excellent chipping resistance and after-coating adherence while ensuring corrosion resistance. The hot-dip galvannealed steel sheet has a base material steel sheet having a predetermined component composition and a hot-dip galvannealing layer containing by mass 7-15% Fe provided on the base material steel sheet surface, wherein the hot-dip galvannealed steel sheet contains within the hot-dip galvannealing layer at least 0.01% by mass of a precipitate including one or more elements selected from the group consisting of Ti, Nb, V, Mo, and W.
Claims4
A hot-dip galvannealed steel sheet comprising:
- a base steel sheet having a chemical composition in terms of mass % such that the base steel sheet contains:
- at least 0.02% but up to 0.30% C;
- at least 0.01% but up to 2.50% Si;
- at least 0.1% but up to 3.0% Mn;
- at least 0.003% but up to 0.080% P;
- up to 0.01% S;
- and at least 0.001% but up to 0.200% Al,
- and further contains one or more than one selected from among at least 0.03% but up to 0.40% Ti;
- at least 0.001% but up to 0.200% Nb;
- at least 0.001% but up to 0.500% V;
- at least 0.01% but up to 0.50% Mo;
- and at least 0.001% but up to 0.200% W, with the balance being comprised of Fe and inevitable impurities;
- and
- a hot-dip galvannealing layer formed on a surface of the base steel sheet and containing, in terms of mass %, 7 to 15% Fe,
- wherein the hot-dip galvannealing layer contains, in terms of mass %, at least 0.01% of precipitates containing one or more than one selected from the group consisting of Ti, Nb, V, Mo and W.
Dependencies are inferred from the claim text.