Thick-walled seamless steel pipes
are widely used in vehicles, airlines, crude oil, chemical plants, engineering construction, heating furnaces, military and other units, and have a significant impact on the social economy. With the development trend of my country's economy, the application field of thick-walled seamless steel pipes has continued to develop, the production scale and specifications have been greatly improved, and the requirements for product quality have become higher and higher. Therefore, thick-walled seamless steel pipes need to pass strict inspections before they leave the factory to meet the requirements of use.
The manufacturing level of thick-walled seamless steel pipes should consider the sales market and support the corresponding mechanical equipment. In the whole process of forging and cold rolling of seamless welded thick-walled seamless steel pipe of stainless steel plate, one of the main performance indicators considering the quality of seamless welded thick-walled seamless steel pipe is parallelism. Most thick-walled seamless steel pipes need to be straightened, and the high efficiency of skew roll straightening is the primary influence. However, for the top deformation of thick-walled seamless steel pipes and large-diameter thick-walled seamless steel pipes, the working pressure straightening method is often used.
The working pressure straightener has a simple and flexible structure. Due to the lack of theoretical research on work stress correction technology, old workers and teachers have always carried out experiments and corrections based on their own work experience. The work pressure correction accuracy is poor, the efficiency is low, and the labor efficiency is high. Therefore, analyzing the deformation behavior of the thick-walled seamless steel pipe in the whole straightening process and accurately calculating the straightening stroke arrangement are the prerequisites to ensure the straightening quality of the thick-walled seamless steel pipe, improve the straightening efficiency and design the scheme of the automatic straightening machine. condition.
In order to improve the corrosion resistance of the thick-walled seamless steel pipe and prolong the service life of the product, it is necessary to pickle and passivate the thick-walled seamless steel pipe to form a protective film on the surface.
1. Grinding and polishing of thick-walled seamless steel pipe branch pipe: After laser cutting, the plastic layer of the branch pipe should be polished with a polishing machine, which is to prevent the plastic layer from melting or even burning during flange welding, thereby damaging the pipe. Sand and polish the plastic layer of the branch with a polisher.
2. The solution to the plastic plating of thick-walled seamless steel pipe: After grinding, heat the pipe outside the pipe with O2 and C2H2 until a part of the plastic layer inside melts. Then the skilled worker wipes the branch pipe evenly with the prepared powder, pay attention to wipe it in time, and wipe the plastic coating of the flange sheet on the waterproof line. During the whole process, the heating temperature should be strictly controlled. If the temperature is too high, small air bubbles will appear during the plastic plating process. If the temperature is too low, the electrostatic powder will not melt completely during the plastic plating process. The above situation will definitely cause the plastic layer to fall off after the pipeline is put into use, and eventually part of the thick-walled seamless steel pipe of the pipeline will be corroded and damaged.
3. Laser cutting of thick-walled seamless steel pipe: According to the specific length of the pipe, the alloy saw and hand-held cutting machine are used for laser cutting of the pipe. When applying water welding in the laser cutting process, ensure the raw material. During laser cutting, flame-retardant and high-temperature resistant raw materials should be used as partitions on both sides of the fracture to maintain the original plastic layer of the raw materials.
4. Connection of thick-walled seamless steel pipe: After filling with plastic, connect the pipe to the pipe. During the whole connection process, add a rubber plate in the middle of the flange and fix the nut until it is closed.
Tips: Seamless black steel pipe is made up of steel that has not being galvanized. Its name comes from the skin, dark-colored iron oxide coating on its surface. It is used in applications that does not requires galvanized steels.