USE 1. Butt welding process According to the working pr […]
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 Resistance butt welding is to cut the power supply after heating the end joint of the steel bar to plastic state, and then heating to reach the plastic connection. This welding process is prone to oxidation and slag inclusion at the joint, and requires that the cross section of the steel bar be smooth and flat, and the power consumption during welding is large, requiring high power of the welder, so it is rarely used.
Flash butt welding Flash butt welding refers to the spraying of molten metal particles from the end joints of the steel bars during the welding process, which is a spark (ie, flash). At the same time as the molten metal is ejected, the oxide and the slag are also taken out, so that the quality of the butt welded joint is good, and thus it is widely used, especially for the joint of low carbon steel and low alloy steel.
2, The use of the use of the welder should pay attention to the following:
Adjust the distance between the two jaws. When the adjusting screw is turned so that the joystick is at the left limit, the gap between the jaws should be the difference between the total extension length and the amount of extrusion of the two weldments. When the joystick is at the right limit, the distance between the jaws should be the total extension of the two weldments plus 2~3mm, the original position before welding.
Adjust the short-circuit limit switch to automatically cut off the power at the end of the weld (to reach the predetermined amount of extrusion).
According to the shape of the weldment, adjust the jaws and make the two jaws at the same level, then clamp the weldment.
In order to prevent the instantaneous overheating of the weldment, the number of adjustment stages should be increased one by one during the test welding, and the appropriate secondary voltage should be selected. In flash butt welding, a higher secondary voltage should be used.
In order to avoid overheating of the parts during welding, the cooling water valve must be opened to pass the water before welding. In order to facilitate inspection, a funnel is arranged in front of the left side of the welder to directly observe the flow of water to check whether there is cooling water flowing inside the welder.