In pure bending, the outer arm wall of the lateral layer is thinned and the inner side is compressed under the effect of external force distance M. The results show that the austenite grain coarseness and extremely uneven grain size will be caused by the solution treatment at 1150 C after bending.

There are two ways to solve the problem of insufficient hardening depth: one is to use coolant method, at present, it is common to add a certain amount of salt in cooling water (5% - 10%). U-shaped bends are also widely used in high-pressure chemical fertilizer pipes. Large R-shaped bends are sometimes needed in heat pipes to meet flexible requirements. Because of the complexity of bending force, it is necessary to make assumptions and simplifications, and the material properties and actual working conditions are difficult to predict. The bending radius of the elbow is not less than 1.5 times the nominal diameter of the pipe when it is bent by the intermediate frequency bender.

Check the piping, installation and wiring of each transmitter (including differential pressure, pressure and temperature transmitters) correctly. Pressure adjustment: the electromagnetic relief valve to adjust the pressure to ensure that the system pressure to meet the required working pressure, generally not higher than 12.5 Mpa.

Shanghai Diyi Pipe Bending Co., Ltd. is a specialized medium-sized enterprise which specializes in the research of stretch bending, intermediate frequency hot bending, core-pulling bending and other processes of profiles, and the production of various metal profiles bending products.

At present, the company has set up factories and offices in Shanghai (Pudong, Baoshan, Fengxian), Anhui and Shandong. It specializes in various profiles bending, incoming material processing and order processing. When the volume is large, it can be flowing around the country. At present, it can process profiles section 6MM-2000MM. The company has the largest diameter of 2 meters of large-scale remote control crown bending. Two sets of machine, its maximum thrust in 2000 T, 1500T, large-scale hydraulic stretch bending machine 8 (maximum processing section 600 mm), with 630 kw, 200 kW intermediate frequency hot bending machine, can hot bend a large round tube under 1 m, the value of 1 million automatic pipe bending machine 89. There are 7 mandrel benders, 2 tube end benders, 2 3-roll benders, 1 7-roll benders, 2 metal pipe circular saws and 1 80-type automatic pipe bender. It has the most complete bending equipment in the industry. The bending products are widely distributed in shipbuilding, automobiles, boilers, petrochemical industry, furniture and so on. Machinery manufacturing, decoration, metal structure, curtain wall decoration and other industries.