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stainless steel plate
What are the factors of corrosion of stainless steel plate?
2015-07-19
How to reduce deformation during heat treatment of seamless steel tube
How to reduce deformation during heat treatment of seamless steel tube?
2021-11-03

How to see the quality of seamless steel pipe after annealing?

The brightness of stainless steel seamless tube after annealing determines the quality of stainless steel seamless tube. There are many factors affecting the brightness of stainless steel seamless tube. The main five points are as follows:

How to see the quality of seamless steel pipe after annealing
How to reduce deformation during heat treatment of seamless steel tube

1. Whether the annealing temperature reaches the specified temperature.

Stainless steel seamless tube heat treatment is generally taken solution heat treatment, that is, people usually so-called “annealing”, high temperature resistant stainless steel seamless tube plate temperature range of 1040~1120℃(Japanese standard).

2. Annealing atmosphere.

Generally, pure hydrogen is used as an annealing atmosphere, the purity of the atmosphere is 99 percent, 99 or more, if the atmosphere is another part of the inert gas, the purity can also be a little lower, but do not contain too much oxygen, water vapor.

3.Furnace body sealing.

Bright annealing furnace should be closed, isolated from the outside air; With hydrogen as a protective gas, only one vent is open (to ignite the exhaust hydrogen).

4. Protect gas pressure.

In order to prevent micro leakage, the protective gas in the high temperature resistant stainless steel seamless tube plate furnace should maintain a certain positive pressure. If it is hydrogen protective gas, it is generally required to be above 20kBar.

5. Water vapor in the furnace.

On the one hand, check whether the furnace material is dry, the furnace material should be dried for the first time; The second is whether the stainless steel seamless pipe into the furnace remains too much water stains, especially if there is a hole above the pipe, do not leak into it, otherwise it will destroy the furnace atmosphere.