How to strictly control the heating rate of the graphite crucible?

1. During the heating process of the graphite crucible, when the temperature is lower than 400 degrees, we also need to slow down the heating rate of the graphite crucible and heat it slowly;

2. When the temperature exceeds 600 degrees, we can speed up the heating rate of the graphite crucible, so that the graphite crucible can quickly reach the processing temperature.

3. When preheating the graphite crucible, the heating rate of the graphite crucible should be as slow as possible to avoid the damage to the graphite crucible caused by sudden heating;