With the progress and development of advanced technology, welded pipe technology has achieved leapfrog development in the past ten years of this century, directly driving the production efficiency of welded pipe and the quality of welded pipe itself. Although the technical quality has been significantly improved, it is still in competition. 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 a current research hotspot in the welded pipe industry. Workers are required to conduct regular non-destructive inspections on operating equipment in daily use, ensuring that Under the premise of employee personal safety, this task requires employees to solve problems in a scientific and systematic way during the inspection process.
1. High-frequency straight seam welded pipe technology
The rapid transformation and development of high-frequency straight seam welded pipe has become an advanced science and technology, and it is becoming more and more perfect, from the initial roll forming improvement to the later row roll forming, to flexible forming, straight edge forming and other The combination of rigid frame can be said that intelligent molding has been initially realized to a certain extent. In addition to the welding and heat treatment power supply technology in the welding process of pipes, it has also become the current all-solid type from the beginning of the pipe type, which is greatly increased on the original basis. The combustion power of fuel is improved, and the operation concept of digital and intelligent automatic control is introduced.
Researchers are committed to the research of high-frequency welding technology for existing problems, put forward practical solutions, improve and correct existing problems, and develop welding technology and quality control methods focusing on strengthening the welding area, which greatly reduces insufficient welding The possibility of welding is very close to the basic material. Through the improvement of management mode, the quality control of high-frequency welded pipe extends to the upstream raw material design and production process, which 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 metallurgical theory. The main technical problems of welding titanium alloy and steel pipe are: First, the welding of titanium alloy and steel pipe is very difficult, and the main influencing factors are The linear expansion process between the titanium alloy and the steel pipe is obviously different, which is caused by the different degree of deformation when the welding is cooled.
Secondly, the mutual solubility between titanium alloy and steel is low. It is formed during the welding process. 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 to produce titanium ferrite. Therefore, titanium and carbon elements in the steel tube generate carbon, then titanium, and titanium also forms traces of chromium, nickel, and iron in the steel tube. And other metal compounds, thereby increasing the brittleness.
3. Welding reinforcement of steel pipe corrosion pits
In the process of transporting oil, natural gas and other materials, due to factors such as corrosive media, soil pH and moisture in the entire area, the pipe wall usually becomes thinner, thereby reducing the strength and thickness of the pipe, which is lower than the allowable range. In addition, displacement causes Mechanical damage and man-made damage will also cause local damage to the soil layer, which will lead to poor pipeline operation and cause huge losses. Therefore, casing maintenance welding and pressure drilling installation are usually used in online welding maintenance operations.
Note: a 106 pipe is formulated specifically for high-temperature and high-pressure service, usually in power generation applications. High-pressure, high-heat service environments put added stress on pipe, so seamless pipe types are preferred in those settings since they’re at less risk of failure under stress than their welded counterparts.