| 摘要 |
PROBLEM TO BE SOLVED: To restrain the nonuniformity generated during the production of a steel sheet such as residual stress within specified range so that the amount of distortion lies within a constant range when the steel sheet is welded. SOLUTION: The temperature distribution in the surface of a steel sheet 8 subjected to hot straightening by a hot straightening device 5 is measured by a thermometer 7, the distribution of residual stress or the like is calculated from the temperature distribution in the steel sheet 8 by a deformation estimating computer 18 or the like, and a prescribed parameter expressing the variation of the amount to be deformed at the time of welding is calculated from the distribution of residual stress or the like. Further, the allowable value previously set in accordance with welding conditions or the like by a demander and the parameter are compared, and in the case the parameter does not lie within the allowable range, straightening treatment is performed by using a straightening device 10, a heat treating furnace 9 or the like to reduce its residual stress or the like.
|
