Patent ID: 9315887
Filing Date: 2016-04-19
CPC Classification: C21D,C22C,C23C

Claim Text:
1. A method for producing a high-strength hot-dip galvanized steel sheet including a steel sheet containing, in percent by mass, 0.01% to 0.18% of C, 0.02% to 2.0% of Si, 1.0% to 3.0% of Mn, 0.001% to 1.0% of Al, 0.005% to 0.060% of P, 0.01% or less of S, and the balance being Fe and incidental impurities, and a galvanized coating layer on each surface of the steel sheet with a coating weight of 20 to 120 g/m 2 per surface, the method comprising, when the steel sheet is subjected to annealing and a hot-dip galvanizing treatment in a continuous hot-dip galvanizing line, controlling a dew point of the atmosphere to −40° C. or lower in every a region of the annealing furnace that has a temperature range higher than 780° C.