| 摘要 |
PROBLEM TO BE SOLVED: To obtain an excellent hot dip metal coating property by securing the sufficient internal oxidized layer regardless of component composition of steel and producing history and even in the case of using a radiating tube heating, such as radiant tube to a recrystallize-annealing before the hot dip coating treatment. SOLUTION: During producing process of a hot dip coated steel sheet containing 0.03-0.2 mass% C and 1.0-3.0 mass% Mn, the internal oxidized layer is formed on the surface layer part of the base iron in the steel sheet particularly by applying the heat treatment in the temperature range of 650-950 deg.C in the atmosphere in which the reduction is not substantially developed, under state of sticking the black scale after hot-rolling.
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