What are the main factors affecting the brightness of stainless steel tube after annealing?

The quality of stainless steel tube is determined by the brightness of stainless steel tube after annealing. There are many influencing factors, and the following are the several main factors:

1.Whether the annealing temperature reaches the specified temperature.

The heat treatment of stainless steel pipe is generally taken solution heat treatment, that is, annealing, the temperature range of 1040~1120℃.During the operation, the stainless steel tube in the annealing area should be in incandescent state, but there is no softening and sagging state.

Duplex stainless steel pipes

2. Annealing atmosphere.

The annealing of stainless steel tube usually uses pure hydrogen as the annealing atmosphere, the purity of the atmosphere is better than 99.99%, if the other part of the atmosphere is inert gas, the purity can also be a little lower, but absolutely cannot contain too much oxygen, water vapor.

3.Furnace body sealing.

Bright annealing furnace should be closed, isolated from the outside air;At the same time, hydrogen is used as the protective gas, and only one vent can be ventilated.When checking the sealing, you can use soap and water to wipe the joint cracks of the annealing furnace to see if the gas is running.The most easy place to run gas is the entrance and exit of the annealing furnace. The sealing ring in this place is particularly easy to wear and tear, so it is necessary to check and replace it frequently.

The stainless steel pipes

4.Protective gas pressure.

In order to prevent leakage, the protective gas in the furnace should maintain a certain positive pressure. If it is hydrogen protective gas, more than 20kBar is generally required.

5.Water vapor in the furnace.

On the one hand, it is necessary to check whether the furnace material is dry, and the furnace material must be dried for the first time.On the other hand, it is necessary to check whether the stainless steel pipe into the furnace remains too much water stains, especially if there is a hole on the pipe, do not leak into it, otherwise it will destroy the atmosphere of the furnace.

The above factors should be paid attention to when annealing stainless steel tubes to ensure high quality annealing.

As the professional manufacturer of flanges, fittings, pipes and other pipeline products, our HEIBEI HAIHAO GROUP can produce and supply various types stainless steel pipes with high quality. Our customers are widely distributed all over the world. If you have any need, welcome to contact us.Email:sales@haihaogroup.com