| 摘要 |
PROBLEM TO BE SOLVED: To provide a method and equipment for manufacturing a galvannealed steel sheet having excellent sliding characteristics, powdering resistance and flaking resistance in press working. SOLUTION: In the temperature region lower than the recrystallization temperature and not lower than (plating bath temperature -30) deg.C in a cooling step after heating of a base material, 0.1-10% strain is applied to the surface of the base material. As a method for application of strain, it is preferable to apply strain by rolling the base material or by making the base material pass while keeping it in contact with rolls of 50-500 mm diameter at >=30 deg. contact angle, and it is also preferable to use, as an apparatus for application of strain, a continuous treatment apparatus having mill rolls and/or bending rolls in a cooling zone.
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