How many stages does the welding process of a medium frequency spot welding machine consist of?

Do you know how many stages are involved in the welding process of intermediate frequency spot welding machines? Today, the editor will give you a detailed introduction to the welding process of a medium frequency spot welding machine. After going through these several stages, it is the welding cycle of the medium frequency spot welding machine.

1. Perform pressure preloading before power on.

The purpose of the preloading period is to make close contact between the welded parts, causing plastic deformation of the protruding parts on the contact surface, damaging the oxide film on the surface, and generating stable contact resistance. If the pressure is too low, only a few protruding parts may make contact, forming a large contact resistance. From this, the metal will quickly melt at the contact point, splashing out in the form of sparks, and in severe cases, the welded part or electrode may be burned. Due to the thickness and high structural rigidity of the welded parts, the surface quality of the welded parts is poor. Therefore, in order to make the welded parts closely contact and stabilize the resistance of the welding area, additional current can be increased during the pre pressing stage or during the pre pressing stage. At this time, the pre pressing pressure is generally 0.5-1.5 times the normal pressure, and the additional current is 1/4-12 of the welding current.

2. To conduct electric heating.

After pre pressing, the welded parts can be welded tightly. When the welding parameters are correct, the metal always begins to melt on the contact surface between the two welded parts at the electrode clamping position, without expanding, gradually forming a molten nucleus. Under the pressure during welding, the molten nucleus crystallizes (during welding), forming a strong bond between the two welded parts.

3. Forging and pressing.

This stage is also known as the cooling crystallization stage, which means that after the molten core reaches the appropriate shape and size, the welding current is cut off, and the molten core cools and crystallizes under pressure. The molten core crystallization occurs in a closed metal film and cannot contract freely during crystallization. By using this method, the crystallized metals can be tightly bonded together without any shrinkage or cracking, allowing the molten metal to crystallize completely before stopping use.