HOT FORGING METHOD FOR DISC-SHAPED MATERIAL

摘要

PROBLEM TO BE SOLVED: To provide a hot forging method capable of preventing dimension errors such as thickness deviation by surely matching the center of a material to be forged with that of a lower die without making a special ring tool.SOLUTION: There is provided a hot forging method for a disc-shaped material comprising placing a material to be forged on a lower die to hot-forge the material using the upper and lower dies. The central part of the lower die has a detachable positioning member for fixing the position of the material to be forged, and the positioning member has a first fitting part which can be fitted to the lower die and a second fitting part which can be fitted to the positioning part provided to the material to be forged. The hot forging method includes fitting the positioning member provided to the lower die to the positioning part provided to the material to be forged to draft the material using the upper die.