Bright annealing is one of the processes in stainless steel industrial welded pipes, which can be divided into online bright solid solution annealing and offline bright annealing. The purpose is to eliminate intergranular chromium deficiency caused by welding and stress generated in the production of welded pipes, so that the quality of welded pipes can meet relevant standards.
The specific principle of bright annealing is to heat the welded pipe in professional equipment to 1050 ℃, and then quickly cool it to below 100 ℃ under the protection of hydrogen sealing. After this process, the welded pipe has high smoothness, better plasticity, and is convenient for subsequent processing. It is the preferred material for many high demand customers.
The online bright annealing equipment developed by Hangao Technology adopts a medium frequency induction heating power supply and is designed with a more optimized DSP+IGBT structure.
The DSP digital control system has complete self-protection and self-diagnosis functions, which are smaller in size, faster in temperature rise, and higher in energy efficiency.
Production process
1. Before production, inert gas should be filled into the equipment and the air inside the equipment should be evacuated to avoid pollution
2. After welding, leveling, and polishing, the pipes enter the online annealing equipment and seal the clamps for sealing
3. When passing through the heating furnace, the induction power supply starts to work by heating the pipe until it stabilizes at 1050 ℃, and then annealing is carried out (quartz tubes are used to connect the heating furnace and cooling cylinder, which can seal and heat the pipe while observing the heating condition of the pipe)
4. The cooling section mainly utilizes graphite kits to ensure rapid heat transfer, cooling the pipes, and protecting them with high-purity hydrogen gas to ensure the high brightness of the annealed pipes
5. After the cooled welded pipe is exported to the sealed protection card, the entire annealing process is completed
