| 摘要 |
A process of production for producing a high strength galvannealed steel sheet by a hot-dip galvanized steel sheet production equipment using an all radiant tube type annealing furnace and a production equipment for the same are provided, comprising continuously hot-dip galvanizing a high strength steel sheet having a content of Si of 0.4 to 2.0 wt % during which making the atmosphere of the reducing zone an atmosphere containing H2 to 1 to 60 wt % and comprised of the balance of N2, H2O, O2, CO2, CO, and unavoidable impurities, controlling the log (PCO2/PH2) of the carbon dioxide partial pressure and hydrogen partial pressure in the atmosphere to log (PCO2/PH2)@-0.5 and the log (PH2O/PH2) of the water partial pressure and hydrogen partial pressure to log (PH2O/PH2)@-0.5, and controlling the log (PT/PH2) of the total partial pressure PT of the carbon dioxide partial pressure PCO2 and water partial pressure PH2O and the hydrogen partial pressure to -3@log (PT/PH2)@-0.5.
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