METHOD FOR ANNEALING STEEL STRIP COIL IN BATCH ANNEALING FURNACE

PURPOSE:To prevent the occurrence of quality defects, such as edge wave, by disposing an object with large heat capacity between a steel strip coil and the ceiling of an inner case. CONSTITUTION:A steel strip coil 2 placed into up-end state on a base plate 3 is covered with an inner case 5 and annealing is done in this state. At this time, an object 1 having high heat capacity as compared with the inner case 5 is disposed between the top of the steel strip coil 2 and the ceiling of the inner case 5. By this method, the occurrence of defects, such as edge wave, in the coil 2 can be prevented because the rapid cooling and rapid heating of the coil 2 can be prevented while the heat stored by the object 1 is released even when the inner case 5 is rapidly cooled or rapidly heated. It is preferable to use the object where, when Q represents the thermal capacity of the object with high thermal capacity and A represents the area of the top of the coil 2, Q is regulated to 1.72X10A to 5.16X10A(Kcal/ deg.C).