For how many minutes should the crucible be left in place after the weld has completed pouring?

After the weld has completed pouring in a thermite welding process, it is crucial to allow the crucible to remain in place for an adequate amount of time to ensure proper solidification and stability of the weld. Leaving the crucible in place for three minutes provides enough time for the molten metal to cool and begin the solidification process uniformly.

During this cooling period, the weld area can develop better metallurgical properties, such as appropriate strength and ductility, which are critical for the integrity of the joint. This interval helps in preventing defects, such as cracking or improper bonding, that can occur if the crucible is removed too soon.

The selected duration of three minutes balances the need for adequate cooling with the practical aspects of the thermite welding process, contributing to a stronger, more reliable weld.