Heating temperature is one of the main processing parameters of the metal heat treatment process. Selecting and controlling the heating temperature is the primary problem to ensure the quality of metal heat treatment. The heating temperature varies with the metal material to be solved and the meaning of the metal heat treatment, but generally it is all heated above the changing temperature to obtain a high-temperature mechanism. In addition, the change must take a certain time. Therefore, when the surface layer of the metal material casting reaches the specified heating temperature, the temperature must be maintained here for a certain period of time, so that the internal and external temperatures are consistent, and the microscope arrangement changes completely. This period of time is called the interval Thermal holding time. When using higher energy relative density heating and surface metal heat treatment, the heating rate is very fast, and generally there is no heat preservation time, while the heat preservation time of organic chemical metal heat treatment is usually longer.

Cooling is also an indispensable process in the process of metal heat treatment processing. The cooling method is different due to different processing processes, mainly controlling the cooling rate. Generally, the cooling rate of quenching is relatively slow, the cooling rate of quenching is faster, and the cooling rate of metal heat treatment is faster. However, there are also different regulations due to different steel grades. For example, hollow mild steel can be quenched at the same cooling rate as quenching.