PRESSING METHOD FOR EDGING HOT SLAB

PROBLEM TO BE SOLVED: To shorten the time necessary for a time of press in the case the amount of edging is small by changing the period of a reciprocating motion in accordance with the amount of edging when the stroke of the reciprocating motion and the amount of edging of a slab satisfy a specified relationship. SOLUTION: The stroke S of the reciprocating motion and the amount ΔW of edging of the slab satisfy the relationship of the formula I. The α means a die movement distance which is necessary to accelerate to a speed at which the edging is possible after a die is started to move from the top dead center position. In the case the reciprocating motion of a press die is executed using a crank mechanism, it is preferable to take the rotational speed ωof the crank as a value which is expressed by the formula II. Where, ω0 and θpmax: the reference rotational speed of the crank and reference screw-down crank angle when the formula I is not satisfied by the relationship between the stroke S and the amount ΔW of edging, R: the radius of the crank, θ0: the crank angle corresponding to a prescribed time which is necessary to acceralation and deceleration for transporting the slab. By high-speed rotation, the contact time of the slab and the die is shortened and the life of the press die is prolonged.