| 摘要 |
PROBLEM TO BE SOLVED: To produce a steel sheet at high yield by continuously measuring core loss value on a continuous annealing line after annealing and controlling the annealing conditions so as to regulate its yield strength to a prescribed range based on the corelation between the measured core loss value and the yield strength. SOLUTION: In a certain compsn., except the case in which crystal grains are remarkably coarsened, the core loss of the material reduces in accordance with the compositional change of unrecrystallization→partial recrystallization→grain growth in one-to-one correspondence to the microstructure. Then, the yield strength similarly changes corresponding to the structure and reduces in one-to-one correspondence to the structural change of unrecrystallization→partial recrystallization→grain growth. Since the core loss value and the yield strength are in one-to-one correspondence based on this two relations, by monitoring the core loss value of the material on line, the yield strength can be grasped with high precision. Thus, by controlling the annealing conditions such as annealing temp., annealing time or the like so as to regulate the measured core loss value to impart yield strength in a prescribed range, the loss in the yield can be prevented.
|
