| 摘要 |
PURPOSE:To prevent over annealing and to stabilize quality by controlling the annealing effect in the heating stage and cooling stage before and after soaking estimated from the heating up curve at the coldest point of the carbon steel coils stacked in a batch type annealing furnace. CONSTITUTION:A heat transmission model taking the shape of convector plates 5a, 5b between coils and air quantity distribution into consideration is made in the stage of stacking carbon steel coils A, B, C in a batch type annealing furnace and annealing the coils at <AC transformation point temp. The temp. at the coldest point of the coils A, B, C is estimated by such model. The parameter corresponding to the mechanical properties of the steel after annealing is defined. Such parameter is calculated by the heating up curve of the temp. at the coldest point estimated from the above-described model. The coils are controlled and annealed so that the calculated value attains the target value after annealing. |
