STOCK FORMING METHOD FOR PREVENTING CRACK AT FRONT END OF ROLLING

摘要

PURPOSE:To reduce both man-hours and cost by half as compared to direct working of the end face of a rolled stock by forming a projection of the size equal to or slightly smaller than the rolling size to the central part at the front end of the rolled stock at the time of forming the rolled stock by hot forging of a steel ingot with a riser. CONSTITUTION:W', W'' of a bloom W obtd. by hot forging of the bottom poured steel ingot are the riser parts thereof and are cut except the riser part W' which is slightly left. The riser part W' and the riser part W' near the boundary face with the body part are scored at each one face by a chisel 1 to form a contraction of a subtense distance D. The riser W' part is then made into the same size as the size of the contracted part by extend forging. The riser part is then discarded except the adequate length to form the projection of the size equal to or slightly smaller than the rolling size in the central part at the top end face of the rolled stock.