| 摘要 |
PURPOSE:To improve the life of a liner, and to reduce the cost of extrusion by using an austenite hot working die steel for an inner liner used for an extruder for hot working and built-up welding a super heat-resisting alloy to the surface to be used and performing an aging treatment therefor. CONSTITUTION:A super heat-resisting alloy 4 such as an ''Inconel 718'' is built-up welded to the inner surface of an inner liner 3 made of austenite hot working die steel. The high-temperature hardness of said super heat-resisting alloy 4 is improved by aging the inner cylinder 3 at about 720 deg.C. The inner cylinder 3 is shrinkage fitted to a tire (outer cylinder) to use them for an extruder. Because the austenite hot working die steel is not softened at this aging temperature, the cylinder 3 maintains sufficiently its high hardness, heat resistivity, and wear resistivity, and the life of liner is prolonged. |
