1. Introduction of online bright annealing equipment:

Online  bright annealing equipment can solve the problem very well. The solid  solution treatment process of stainless steel welded pipe mostly adopts  online black solid solution and acid pickling or off-line bright solid  solution, which brings environmental protection problems. Bright  annealing stainless steel equipment consists of IGBT transistor inverter  medium frequency power supply cabinet and slot compensation capacitor  cabinet. Metash, a power supply system, consists of induction heating  coil, cooling water jacket, gas protection device and infrared  thermometer. Metash, a bright solid solution system, consists of  water-metash, water heat exchanger, external circulation water and  cooling device, cooling system, pipe cleaning device and electrical  control system.

2. Automation Workflow:

Bright  annealing stainless steel equipment will heat stainless steel welded  pipe with induction heating coil to the temperature required for solid  solution, and complete the homogenization of austenite, that is, solid  solution process. The graphite cooling fixture at the inlet end of the  water jacket 1 is rapidly cooled, and the temperature is lowered below  800 C to prevent the precipitation of carbon and chromium in order to  keep the solid solution effect. However, the cooling effect of indirect  cooling always brings a small amount of carbon and chromium  precipitation, and chromium precipitation rate is slower than that of  carbon, resulting in chromium-poor zone (chromium-poor zone is the main  cause of intergranular corrosion). However, the chromium-poor zone can  be eliminated by insulating chromium in water jacket 1 between 550 and  750 C and providing a diffusion time for chromium. However, the  sensitization zone of stainless steel is 550-750 (?) C, but because the  rapid cooling of water jacket 2 graphite cooling fixture on welded pipe  blocks the time effect of sensitization of stainless steel, the  sensitization result will not appear. After cooling by water jacket 2,  the temperature of the steel pipe should be below 130 C.

3, process characteristics:

The  stainless steel pipe is heated by induction heating to the temperature  required for solid solution (304 material 1040 C), and solid solution  treatment is carried out in the sealed device with hydrogen as  protective gas to improve the structure of the weld seam and eliminate  the stress so as to enhance the corrosion resistance. The welded pipe  after solid solution treatment can be changed by using hydrogen as  protective gas. Light and speed up cooling. The stainless steel welded  pipe is cooled by indirect cooling after heating to the solid solution  temperature to keep the welded pipe bright.

4. Device parameters