Spot Welding

Spot welding - a kind of resistance welding in which the parts are connected to a separate contact areas, the limited area of the ends of the electrodes that transmit compressive force and the supply current.

The essence of the process
Welded blanks impose on each other and are usually clamped between two metal electrodes with an application to him force F St. . After that the power is turned on, which causes the wires, electrodes and the workpiece electrical current of up to several units or tens of kA. As a result, the contact zone along the axis of the electrode pieces begins the process of heating and melting the metal. The sealing band of plastically deformed metal, adjacent to the melt, protects it from splash and interaction with the air.

The spot welding process

Upon reaching the desired amount of molten metal, electric current is switched off (phase forging), which leads to the cessation of heat evolution in detail and melt crystallization. Forging can be done without increasing the pressure or high blood pressure. After some time, with the electrode clamping force is removed. The resulting compound is similar in shape and is welded rivet "point."

Loops and timeline of spot welding

The structure and size of weld "points" depend on the strength of the current duration of its course, the shape and size of the working electrode surface, compression force and the state of the surfaces of parts. The typical diameter of the core points of 4-12 mm.

For heating of blanks for spot welding used short pulses of variable (usually a power frequency of 50 Hz, less frequency of 1000 Hz), DC or unipolar current.

The electrodes are made mostly of copper and its alloys with high thermal and electrical conductivity.

Welding technology:

manual arc welding semi-automatic welding argon arc welding machine welding electroslag welding plasma welding laser welding electron beam welding

gas welding resistance welding spot welding seam welding projection welding butt welding welding underwater welding in space