About steel pipe welding processing technology

With the progress and development of advanced technology, welded pipe technology has achieved leapfrog development in the past ten years of this century, which directly drives the production efficiency of welded pipe and the quality of welded pipe itself. In the fierce market, the quality requirements for welded pipes are even higher. Therefore, improving the quality of steel pipe materials on the existing basis is the current research hotspot in the welded pipe industry. Workers are required to carry out regular non-destructive testing on operating equipment in daily use. Under the premise of employee personal safety, this job requires employees to solve problems in a scientific and systematic manner during the inspection process.

1. High frequency longitudinal welded pipe technology
The rapid transformation and development of high-frequency straight seam welded pipes has become an advanced science and technology and is becoming more and more perfect, from the initial roll forming improvement to the later line roll forming, to flexible forming, straight edge forming and other With the combination of rigid frames, it can be said that intelligent molding has been initially realized to a certain extent. In addition to the welding and heat treatment power technology in the welded pipe process, it has also become the current all-solid-state type from the beginning of the pipe type, greatly increasing on the original basis. fuel combustion power.
Researchers are committed to the study of high-frequency welding technology in response to existing problems, propose practical solutions, improve and correct existing problems, develop welding technology and quality control methods focusing on strengthening the welding area, and greatly reduce the number of insufficient welding The possibility makes the welding performance very close to the basic material, improves the product performance and quality level, and is widely used in key parts such as oil well pipes.

2. Welding process of titanium alloy and steel pipe
The welding process of titanium alloy and steel mainly depends on the difference between the two materials and the compatibility of metallurgy theory. The main technical problem in the welding of titanium alloy and steel pipe is: the welding of titanium alloy and steel pipe is very difficult, and the main influencing factor is titanium The linear expansion process is obviously different between the alloy and the steel pipe, which is caused by the different degrees of deformation during welding cooling.
Secondly, the miscibility between titanium alloy and steel is low, which is formed during the welding process, and the hard and brittle intermetallic compound, usually titanium ferrite, is mainly formed by the diffusion of titanium and iron during the welding process, and The supersaturation of iron in titanium will continue for a certain period of time, resulting in titanium ferrite.

3. Welding reinforcement of steel pipe corrosion pits
In the process of transporting materials such as oil and natural gas, due to factors such as corrosive media, soil pH and moisture in the entire area, the pipeline wall is usually thinned, thereby reducing the strength and thickness of the pipeline, which is lower than the allowable range. In addition, the displacement caused The mechanical damage and man-made damage will also cause local damage to the soil layer, which will lead to poor operation of the pipeline and cause huge losses. Therefore, casing maintenance welding and pressure drilling installation are usually used in online welding maintenance operations.