Abstract:The on-line continuous ultrasonic automatic damage instrument detects the welded seam, which ensures a 100% non-destructive testing coverage of the sp
The on-line continuous ultrasonic automatic damage instrument detects the welded seam, which ensures a 100% non-destructive testing coverage of the spiral weld. If there is a defect, it will be marked automatically and sprayed, and the production personnel will mark the defect in time based on the process parameters at any time. After the steel pipe is cut into a steel pipe with an air plasma cutting machine, each batch of steel pipes must undergo a rigorous first inspection to check the mechanical properties, chemical composition, melting conditions, surface of the steel pipe and non-destructive testing to ensure the manufacture of the steel pipe. The process is qualified before it is officially put into production. Use manual ultrasonic and X-ray to check the position of the continuous sound detection defect mark on the weld. If there are defects, non-destructive testing shall be carried out after repairing until the defects are confirmed. Each steel pipe needs to go through the hydrostatic pressure test. After the hydrostatic test, the pressure of each steel pipe is radially sealed.
The rise of the bicycle manufacturing industry led to the development of small-caliber spiral steel pipe production technology. During World War II, the manufacturing of ships, boilers and aircrafts, the manufacturing of thermal power boilers after World War II, the development of the chemical industry, and the drilling, production and transportation of oil and natural gas. It has effectively promoted the development of the steel pipe industry in terms of variety, output and quality. Steel pipe is used to transport liquids and powdered solids, exchange heat, and manufacture mechanical parts and containers. At the same time, it is also an economical steel. Building structural grids, columns and mechanical supports made of steel pipes can reduce weight, save about 20 to 40% of metal, and realize the mechanization of industrial construction. The use of steel pipes to build highway bridges not only simplifies construction and saves steel, but also greatly reduces the area of the protective layer and saves costs. According to the production method, steel pipes can be divided into seamless steel pipes and seam steel pipes, referred to as direct welded steel pipes.
Small diameter spiral steel pipe uses continuous welding wire as electrode and filler metal. When working, the welding area is covered with a layer of granular flux. The arc burns under the flux layer, melting the end of the wire and the local base material, forming a weld under the action of the arc heat, the upper part of the flux melts the slag, and metallurgical reaction occurs with the liquid metal. The slag floats on the surface of the molten metal pool. On the one hand, it can protect the weld metal and prevent air pollution. It can also cause physical and chemical reactions with the molten metal to improve the performance of the weld metal. On the other hand, it can also gradually cool the weld metal. . Large welding current can be used for submerged arc welding. The biggest advantage is good welding quality and fast welding speed. Therefore, it is particularly suitable for welding large-diameter spiral steel pipes. Among them, automatic welding is mainly used, which is widely used in the welding of carbon steel, low-alloy structural steel and stainless steel.