The production process of welded pipe welding

Welded pipe refers to the steel pipe with joint on the surface which is made of steel strip or steel plate bent and deformed into circular or square shape. The blank used for welded pipe is steel plate or strip steel. How can the steel strip or plate be welded together? What are the welding skills?
1, according to the use of points, welding welded pipe has general purpose and high temperature and high pressure, etc., the latter pipe is often special alloy steel, must consider and solve the problem of shrinkage crack in the welding process and heat affected zone pipe mechanical properties do not change too much due to the influence of welding operation.
2. According to the thickness of pipe wall, pipes made of relatively thin materials such as steel strips can be welded by high frequency welding, and some thin-wall pipes can be welded by protective gas method; Pipe with wall thickness greater than 2mm can be manually welded.
3. According to the diameter of the pipe, it can be divided into those with small diameter that can only be welded on one side and those with small diameter that can be welded on both sides by technicians who can drill into the pipe. Single-sided welding on the welder technology requirements, can do single-sided welding two forming, through the steel ball test, ensure that the cross-sectional area through the ability and weld forming are in line with the design requirements.
4, as long as the material is high strength alloy steel pipes, including heat resistance, pressure, wear-resistant, resistant to low temperature of the alloy steel pipe, are emphatically on the welding process to carry out the prevention martensite structure due to the welding of high temperature, the tendency of cracks, the craft is general requirements, electrode to choose good, and baking to welder use, according to the requirement Before welding on both sides of the weld to oil, water, rust, debris, clean, welding line energy as small as possible, as far as possible to reduce the swing of the welding process, the last welding line as far as possible to the heat affected zone of annealing effect. After welding slow cooling, covered with asbestos cloth and so on.
5. In order to ensure the welding quality of pipes, welders should be trained and tested to be qualified. Good welder to weld steel pipe, in addition to the basic theory, to hone skills, pipe welding process may contain the downhand welding, vertical and overhead welding several gesture (cases) pipe cannot turn, choose good to take care of the size of the current to the vertical and overhead welding forming (some pipe is not very big, once forming, cannot be halfway to adjust current), process control, good arc stability and forming Can swing properly, to shape and necessary swing well.


Post time: Jan-12-2022