1. Butt welding process: According to the working principle of the butt welding machine, the butt welding process can be divided into two types: resistance butt welding and flash butt welding:
Resistance butt welding is to heat the end joints of steel bars to a plastic state, then cut off the power supply, and then reheat to achieve a plastic connection.
This butt welding process is prone to oxidation and slag inclusions at the joints and requires the cross-section of the steel bars to be smooth and clean. At the same time, it consumes a lot of power during welding and requires a high-power welder, so it is rarely used.
Flash butt welding means that during the welding process, molten metal particles are ejected from the end joints of the steel bars, showing sparks (i.e. flashes).
While the molten metal is ejected, the oxides and slag inclusions are also brought out, making the butt welding joint of good quality, so it is widely used, especially for the butt jointing of low carbon steel and low alloy steel.
2. When using the butt welding machine, you should pay attention to the following matters:
Adjust the distance between the two jaws. When the adjustment screw is turned to make the joystick at the left limit, the distance between the jaws should be the difference between the total extension length and the extrusion amount of the two weldments.
When the joystick is at the right limit, the distance between the jaws should be the total extension length of the two weldments plus 2~3mm, which is the original position before welding.
Adjust the short-circuit limit switch so that it can automatically cut off the power supply when the welding is completed (the predetermined extrusion amount is reached).
According to the shape of the weldment, adjust the jaws so that the two jaws are at the same level, and then clamp the weldment.
In order to prevent instantaneous overheating of the weldment, the adjustment levels should be increased gradually during trial welding, and the appropriate secondary voltage should be selected. When flash butt welding, a higher secondary voltage should be used.
In order to avoid overheating of components during welding, the cooling water valve must be opened to allow water to flow before welding.
In order to facilitate inspection, there is a funnel in front of the left side of the welding machine, which can directly observe the water flow situation to check whether there is cooling water flowing inside the butt welding machine.
