| 摘要 |
PURPOSE:To prevent oxide layer from being formed on the surface of a high temperature product directly after an extruding work by providing, on a die assembly, a fluid supply path on a front end part side which connects with a fluid supply path on a base part side and opens to the internal part of the die assembly at a position directly after an extruding part. CONSTITUTION:Before a billet 40 is pressurized, an electromagnetic selector 32 is set previously at an open position and nitrogen gas is supplied from a nitrogen gas supply source 31 to a gas supply path 29. In this state, the billet 40 is pressurized as the nitrogen gas is supplied. At this extrusion time, the nitrogen gas is supplied from a 1st front end side gas supply path 35 to the external side of a product 41 and the nitrogen gas is supplied from a 2nd front end side gas supply path 36 to the internal side of the product 41. In this manner, since the circumference of the high temperature product 41 directly after extrusion is in the atmosphere of nitrogen gas, oxide layer by the contact with the atmosphere is not formed on the surface of the product 41, billet material such as Al, etc., which are stuck to the internal part of a die assembly 14, too, are not oxidized, the surface of the product 41 is not injured by oxides and the surface of the product 41 is improved in quality. |
