METHOD OF EXTRUDING HOLLOW LIGHT METAL MEMBER, DIE FOR EXTRUDING HOLLOW LIGHT METAL, AND MEMBER FOR EXTRUDING HOLLOW LIGHT METAL

摘要

A method of extruding a hollow light metal member capable of always stably manufacturing the hollow light metal member (product) with excellent mechanical properties by using a hollow die such as a bridge die and efficiently improving the quality of the product matching the requested level of strength at low cost, comprising the steps of dividing, converging, and welding a light metal raw material with the hollow extruding die and extruding the material through a die hole to form in a specified cross sectional shape. A deformed amount provided to the light metal raw material after the converging and welding is maintained at 1.8 or higher before the extrusion.