| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a hot-dip galvanized steel sheet having excellent plating wettability and pickup resistance using, as a base material, a steel sheet including Si and Mn which are easily oxidizable elements.SOLUTION: When a steel sheet having predetermined components is subjected to an annealing treatment and a treatment for applying a hot-dip galvanized layer in continuous hot dip galvanizing equipment, the steel sheet is heated up to a plate temperature T°C (200≤T≤500) within aseconds (10≤a≤500) in such a nitrogen atmosphere that the logarithm ratio of the steam partial pressure PHO to the hydrogen partial pressure PH, log(PHO/PH), is ≥-4 to ≤-2, in a first process, then heated up to T°C (600≤T≤1,000) from the plate temperature T°C within aseconds (20≤a≤1,000) in such a nitrogen atmosphere that log(PHO/PH) is ≥-1.5 to ≤+0.5, in a second process, and uniformly heated at a plate temperature T°C (-100≤T-T≤100) for aseconds (30≤a≤1,500) in such a nitrogen atmosphere that log(PHO/PH) is ≥-4 to ≤-2, in a third process. |
