| 摘要 |
1,153,798. Casting processes. BÍHLER & CO. A.G., GEB. 14 Dec., 1966 [14 Dec., 1965], No. 55975/66. Heading B3F. In a method of producing ledeburitic tool steels the hollow interior of a tube is filled by remelting with an akin material, as hereafter defined, whereby a substantially uniform metallurgical structure is obtained throughout the resulting solidified ingot. By " akin material " is meant a material which has the same temperature expansion and phase transformation characteristics as the material of the tube. The tube may be cast or formed by boring a casting or alternatively formed of a material which has been previously worked. The tube is filled by a consumable electrode and in order to further control the final crystalline structure of the resulting ingot, the tube may be preheated and the external surface of the tube below the level of molten metal therein may be cooled by spraying water thereon. |
