| 摘要 |
PROBLEM TO BE SOLVED: To shorten a heating time of a billet, while preventing generation of an oxide scale on the billet, to reduce a scale loss of the billet, and to improve production efficiency, when heating the billet up to a required temperature during hot forging.SOLUTION: A billet heater 1 includes a far-infrared ray heating furnace 2 which is a preheating furnace for preheating a plurality of billets 10, 10, etc., up to a temperature below an oxidation temperature of the billets 10, and a high frequency heating furnace 3 which is a main heating furnace for high-frequency heating up to a required temperature during hot forging, the billets 10 preheated by the far-infrared ray heating furnace 2.SELECTED DRAWING: Figure 1 |
