摘要 |
The invention relates to a stopper rod adapted to deliver gas during pouring of molten metal comprising a stopper body having an internal chamber and a gas discharge port, a bore connecting the internal chamber to the gas discharge port, the internal chamber and the bore defining a gas passageway. According to the invention, the walls of the gas passageway are provided with a layer of a material which will not produce carbon monoxide at the temperature of use. The stopper rod of the invention does not contaminate the gas passing therethrough.
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