Stainless Steel Tube Bright Annealing Process Description(1)

  • By:Hangao
  • Date:2021/09/29

Process Description

The bright annealing machine is a special equipment for heating stainless steel pipes to 1050 degrees Celsius on-line and then rapidly cooling to below 100 degrees Celsius under hydrogen protection. The induction heating coil and cooling system are built into the sealed piping. The main feature of this system is the use of non-reusable hydrogen, which has a very small flow rate of only a few liters per minute. The gas used is pure hydrogen, which is not dangerous because it is present in a small amount in the gas pipe. At the same time, the exhaust gas emitted is burned to prevent hydrogen from diffusing into the surrounding air, thereby avoiding accumulation of dangerous concentrations in the surrounding space. The heated stainless steel tube is cooled by a "heat transfer" method in a dedicated closed cooling tunnel. These characteristics are the reason why the system requires only a small amount of gas for bright annealing compared to other systems. The protection of the gas control system and equipment is automatically controlled by the PLC. Therefore, the reliability and safety of the equipment are guaranteed. The IF power supply uses a crime IGBT variable frequency power supply, and its output power is suitable for all pipe diameters. As a core technology of Hangao Tech (SEKO Machinery), our online bright annealing funace for stainless steel tube making machinery is always one of our hot sale products.

Device Description

The main equipment for online bright annealing consists of the following parts:

Heating section

1) Intermediate frequency power supply

The induction heating portion of the bright annealing device is based on the IGBT transistor frequency conversion technology. The output frequency can be varied from 20-30 kHz depending on the needs. The induction heating power supply uses solid state IGBT technology to match the output and load. It has a power factor of 95%, no compensation, and an efficiency of 85%. A very important technical indicator for power output control is very accurate up to ±1%.

2) Induction coil

The induction heating coil is a multi-turn copper tube screw line structure. The inside of the copper tube is cooled by soft water. The induction coil is about 800 mm long and is lined with a tube for insulation in a controlled atmosphere. The heat treatment time is short, and the steel pipe can be heated from room temperature to 1050 degrees Celsius in just ten seconds.

2. Cooling tunnel

The heated stainless steel tube enters the cooling passage where it is cooled by heat exchange with hydrogen. Hydrogen cools the heat. As with the heated section, all cooling work is carried out under a pure hydrogen atmosphere. At the end of the cooling tunnel, the temperature of the stainless steel tube is cooled to below 100 degrees Celsius, so the steel tube can be safely placed in the air and cooled by a small amount of water for final spray. Welcome to inquire us !




Guangdong Hangao Technology Co., Ltd.

We are always providing our customers with reliable products and considerate services.

If you would like to keep touch with us directly, please go to contact us

  • Home


  • Tel


  • Email


  • Contact