| 摘要 |
A nozzle for molten metal casting operations wherein is provided with an annular groove either in an exterior surface or, in the case of a nozzle having a hard metal insert, in an interior surface. In either case, the groove is filled with a material having a high heat conductivity and which is either in a location where it can receive heat directly from a localized source such as gas fired torch or in thermal circuit with such a location; i.e. connected to the location by some intermediate leg of high thermal conductivity material. In one specific embodiment the groove is filled with copper and is connected to a series of spiral extension grooves. In another embodiment is formed in an interior surface where it is adjacent a hard metal insert which increases the durability of the nozzle in repetitive make and break operations.
|
