In the course of use, resistance welding machines occasionally exhibit less desirable welding results. Mainly have severe scorching of the welding area, holes, rough solder joints; splash more; weak welding strength; brittle welding and other aspects. Below we analyze in detail the causes of these bad welding effects:
1. The welding site has serious burns, holes, and rough solder joints. There are five main causes:
a. Insufficient electrode pressure
b. Welding current is too large
c. Longer power-on time
d. The shape of the electrode tip is not good
e. Insufficient cooling of the tip
2, splash more - there are four main reasons:
a. The surface quality of the workpiece being welded is poor (oil, rust, dust, etc.)
b. Short initial pressurization time
c. Insufficient electrode pressure
d. Welding current is too large
3, weak welding strength - there are three main reasons:
a. Insufficient welding current
b. Electrode pressure is too large
c. Short power-on time
4, the brittle welding point - the main reason is:
Short annealing time
Insufficient pressure or pressing force. The phenomenon is that the point and seam welding spatters are serious and the weldment slips during welding. The reason may be:
1) In-cylinder seals have been damaged. At this time, the cylinder exhaust will not stop. If the welder pipe does not leak, continuous exhaust sound can be heard.
2) The stroke of the cylinder has reached the limit. At this time, it is advisable to remove the weld and check the stroke.
3) When the seam welder or the projection welder adopts a double valve, if the pressurization valve fails, the welding head can descend from its own weight after the rising valve exhausts.
1) When the welding machine adopts the dial setting time, the contact of one of the dials of the dial causes a failure in the 8421 code circuit, resulting in a considerable reduction in the welding time.
2) In welders using NAND circuits, some welders use 100Hz frequency division to make 50Hz counts. When the frequency division manifold is damaged, the welding time is reduced by half.
Thyristor short-circuit damage has entered continuous seam welding.