| 摘要 |
510,227. Casting processes. DEUTSCHE ROHRENWERKE AKT.-GES. Jan. 31, 1939, No. 3229. Convention date, April 28, 1938. [Class 83 (i)] In casting hollow steel &c. ingots by allowing a layer of the cast metal to solidify and then pouring out the still molten centre, the metal, directly after casting, is covered with a layer of heat producing material, such as a mixture of coal, coke, and aluminium, then a layer of ground open-hearth slag, and then a layer of fire clay powder. The wall thickness of the hollow ingot may be up to one third the diameter of the ingot or in the case of very large ingots, say 2,000 millimeters in diameter and 6 meters long, up to one quarter. |
