
Preheating for welding and heat treatment with electric resistance
The Tecnotrat preheating system operates using electric resistances and automated machines, ensuring excellent uniformity, temperature control in the heated area, and low levels of thermal stress. Without preheating for welding, thermal stresses increase during welding, which can lead to cracks in the welded piece.
Preheating enhances hydrogen diffusion and facilitates its removal from the weld joint, as hydrogen promotes crack formation. Therefore, preheating removes moisture present at the time of welding execution. The heat treatment process also follows the same electric resistance heating method. In this process, heat is transferred to the piece through radiation and controlled convection, allowing the heat-affected zone to be uniformly heated.
The use of thermocouples installed for each resistance group, coupled with fully automatic equipment, eliminates the possibility of localized overheating, which can cause damage and undesirable structural transformations to the material. Electric resistance heat treatment provides more than just stress relief in the weld joint, as it substantially reduces the high levels of stresses occurring during welding due to metallurgical transformations, contractions, and dimensional constraints imposed on the base material by the weld.




Localized Heat Treatment on Piping




Localized Heat Treatment in Piping
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