The process of heat treating is the method by which metals are heated and cooled in a series of specific operations that never allow the metal to reach the molten state.

金属热处理过程其实是一系列具体的操作，通过这些操作加热与冷却金属，但加热时进行控制，使得金属不达到熔融的状态。

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Heat Treating, Annealing, Aging of metals.

热处理，退火，金属老化。

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Gas, oil and electric furnaces are commonly used for heat treating metals.

金属热处理常用煤气炉、油炉和电炉。

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