摘要 |
A method of heat-treating and, particularly, annealing, a ductile cast iron pipe in the form as centrifugally held against the wall of a centrifugal casting mold. The casting within the mold is heat-treated by introducing a hot gas of elevated temperature into the hollow of the casting. At the initial stage, the casting within the mold is in red-hot condition and, therefore, introduction of the hot gas into the hollow of the casting results in control of the dissipitation of heat energies from the red-hot casting to delay or slow down a cooling rate of the casting.
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