High-temperature extrusion manner of suspicious looking hollow section and mandrel null for high-temperature extrusion

摘要

PURPOSE: To prevent recessed flaws generated on the hollow surface of a special shaped hollow shape material, in a hot extrusion working, and to facilitate aligning of a guide hole and a mandrel by extruding a billet from a die hole after piercing the guide hole of a billet and the die hole with a specific nose. ;CONSTITUTION: A nose, whose cross-sectional shape resembles the hollow part of a special shaped hollow shape material and whose cross-sectional dimension is larger than the mandrel 1 and smaller than the hole of a die 5, is attached to the tip end of the mandrel 1 freely attachably and detachably and also with a rotation stopper. In other words, since the nose 3 is larger than the mandrel 1 in the cross section, a pace for lubricating glass is formed between the circumferential surface of the mandrel 1 and the guide hole of a billet. The lubricating glass supplied to the guide hole of the billet is evenly and sufficiently supplied over the entire circumferential surface at the time of extrusion. Consequently, scabs due to the uneven supply of the lubricating glass is prevented from generating on the inside surface of an extruded product.;COPYRIGHT: (C)1995,JPO