Views: 0 Author: Site Editor Publish Time: 2021-06-04 Origin: Site
Thin butt-welded flanges are often single-sided welding. In order to achieve penetration, the butt-welded flange should be left with a space of 1.4~1.6mm.
Using thin welding wire (0.8~1.2mm in diameter) for short-circuit transfer welding, the welding current is 120~130A, and the arc voltage is 18~19V. When operating the welding torch, aim at the center of the groove, similar to the right welding method.
At this time, the molten pool should be held in a straight line or slightly shaken by the effect of arc force and surface tension. When the welding speed is too slow, the molten pool metal sags and the weld bead appears uneven. When the welding speed is severe, the molten pool metal is lost. Therefore, you should pay attention to the situation of the molten pool when welding, and schedule the welding speed and shaking method in time. If the inclination of the welding torch is too large, a convex weld bead and undercut will be formed.
Non-destructive testing of butt welding flanges is a method used in the inspection of pressure vessels. It can be used in all aspects of vessel manufacturing. In the inspection of raw materials, steel plates for pressure vessels, high-pressure seamless steel pipes, and grade IV or above whose thickness exceeds a certain value Forgings of steel grades need to be subjected to ultrasonic testing, the appearance of grooves after thermal processing of grade steels need to be tested, and the welds on the container should be subjected to radiographic or ultrasonic testing. In addition, non-destructive testing is also required in the aspects of welder operation skill inspection, welding process determination, product test board, and in-use pressure vessel inspection.
Because non-destructive testing (NDE or NDT) is a non-destructive inspection method, it occupies a very important position in the inspection of products. It uses the mutual effects of sound, light, electricity, heat, magnetism and radiation with substances to explore the appearance or internal defects of materials, parts or equipment, and to determine their position and size without jeopardizing the function of the inspected object. , Shape and type of method.
The butt welding flange continuous arc welding method uses a smaller welding current and a smaller diameter electrode. During the welding process, the arc continues to burn stably, and the smaller groove space is evenly swayed forward to make the welding The method of forming a uniform weld seam with poor parts is simple to operate, with little method change, simple to master, and the welding seam is not good in composition, fine and regular, good internal quality, excellent mechanical function, and its disadvantage is that it is bound by the gap of the groove. The problem of difficulty in joints when the acid electrode is connected is outstanding. The continuous arc welding method is mainly used in the welding of basic electrode orientation and the vertical welding and overhead welding of acid electrode.