| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a high strength hot dip galvanized steel sheet and a high strength hot dip galvannealed steel sheet excellent in workability and plating adhesion, and to provide a high strength hot dip galvannealed steel sheet excellent in plating adhesion and corrosion resistance. SOLUTION: The method for producing a high strength hot dip galvanized steel sheet is the one in which a slab of steel contg., by weight, <=0.10% P and <=1.00% Mo is hot-rolled, is pickled, is thereafter heated to >=750 deg.C in an annealing furnace as it is or after cold rolling, is cooled, the thickened layer of the components is removed in the steel of the steel plate surface by pickling, and is next subjected to heating reduction under the reducing conditions of P oxides, and is subsequently applied with hot dip galvanizing, and moreover, alloying treatment is executed. Furthermore, the high strength hot dip galvannealed steel sheet is obtd. by treating a steel sheet contg. <=1.00% Mo with hot dip galvanizing and executing heating alloying treatment, and, the content of Fe is controlled to 8 to 11 wt.%, and the content of Mo is controlled to 0.002 to 0.11% in the plating layer.
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