| 摘要 |
<p>A process for the fusion, purification and casting of metal alloys comprises fusing the metal in a closed receptacle in an atmosphere of gas containing carbon dioxide and substantially free from oxygen, hydrogen, water, hydrocarbons, sulphides and hydrosulphides, then passing, at superatmospheric pressure, a gas of substantially the same composition as the former mentioned gas but containing a minor amount of carbon monoxide for starting the purifying action, then discontinuing carbon monoxide while continuing passing carbon-dioxide, and finally casting the molten metal into an enclosure filled with a gas of similar composition to the gas used for starting the purifying action. The gas may be passed through the molten metal at a pressure of about 250 m.m. mercury above atmospheric pressure. The gas used to commence refining and to fill the casting enclosure may consist of 30 per cent carbon dioxide, 3 per cent carbon monoxide, balance nitrogen.</p> |
