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　　If long radius straight seamless pipe is made, such as the pipe of billet manufacturer, the specification shall be selected first and the pipe material shall be put forward. According to the theoretical calculation, the elongation rate is generally between 44% - 46%, and it goes back. The general elongation of a short radius of 220 mm is 60%.

　　After selecting the raw materials, cut the materials according to the specification of straight seamless pipe, and then consider the scientific radius, which can be calculated through theoretical calculation, and then cut off with this length as the fixed length. Finally, the material is hot rolled. Everyone may have seen the coiler, but it's actually very simple. It is a semicircular core or roller. The roller changes from thin to thick. The rolling process is a process of bending the extension belt. There is a support at the back to thread the blanking pipe section into the roller, and there is a archway at the back to fix the roller. There is an electric wheel in the middle. Some of the electric wheels are driven by hydraulic transmission, and some are driven by mechanical transmission, that is, lead screw transmission, and then roll the electric wheel forward. The electric wheel rolls the pipe forward along the roller. There is an induction ring outside the roller to heat and heat the pipe. Then the electric wheel rolls the pipe down and processes one. After rolling, the straight seamless steel pipe shall be flattened in this hot state. Because some straight seamless pipes will be distorted after improper treatment, which is not allowed.

　　Due to the existence of welds, NDT shall be carried out. Due to the existence of welding stress, heat treatment is also required. There are two more processes for welding straight seamless steel pipe: one is flaw detection and the other is heat treatment. Other procedures are the same.

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