Patent ID: 9598755
Date: 2017-03-21
CPC Classifications: B32B,C21D,C22C,C23C

Claim:
1. A high-strength galvanized steel sheet comprising: on a mass percent basis, C: 0.010% or more and 0.06% or less, Si: more than 0.5% and 1.5% or less, Mn: 1.0% or more and 3.0% or less, P: 0.005% or more and 0.1% or less, S: 0.01% or less, sol.Al: 0.005% or more and 0.5% or less, N: 0.01% or less, Nb: 0.010% or more and 0.090% or less, and Ti: 0.015% or more and 0.15% or less, the Nb and C contents % by mass of the steel satisfying the relation of (Nb/93)/(C/12)<0.20, C* given by the following formula (1) satisfying 0.005≦C*≦0.025, and the remainder being Fe and incidental impurities without addition of V, wherein ferrite constitutes 70% by area ratio or more, martensite constitutes 3% by area ratio or more, the average r-value Lankford value is 1.2 or more, and the hole expansion ratio λ is 80% or more: wherein C, Nb, Ti, and N denote the C, Nb, Ti, and N contents % by mass of the steel, respectively, provided that if Ti−(48/14)N≦0, then Ti−(48/14)N=0.