There are five factors that affect the brightness of stainless steel pipes

There are five factors that affect the brightness of stainless steel pipes: annealing temperature, annealing atmosphere, furnace seal, protective gas pressure and water in the furnace.

1. Annealing temperature.

The annealing we often say is actually the solid solution heat treatment of stainless steel. Whether the annealing temperature reaches the specified temperature will also affect the brightness of the stainless steel pipe. The annealing temperature is 1120 degrees Celsius. We can observe through the annealing furnace that the stainless steel pipe should generally be incandescent, and will not be softened and hung.

2. Annealing atmosphere.

Most people will ask whether the annealing atmosphere also affects the brightness. Yes. At present, pure hydrogen is used as the annealing atmosphere. Note that the purity of the atmosphere is preferably greater than 99.99%. If another part of the atmosphere is an inert gas, the purity can be slightly lower. However, it must not contain too much oxygen and water vapor, otherwise the brightness will be greatly affected.

3. Furnace body seal.

The sealing of the furnace body will also affect the brightness of the stainless steel pipe. The annealing furnace is usually enclosed and isolated from the outside air. Hydrogen is usually used as a protective gas, with only one vent for igniting the discharged hydrogen. Now I will show you the test method: rub soapy water on every seam of the annealing furnace, and if there are bubbles, there will be air leakage. In addition, the joints are particularly prone to wear and tear and should be regularly maintained and tested.

4. Protect gas pressure.

The protective air pressure in the furnace must be maintained at a certain positive pressure to prevent microleakage. In the case of hydrogen shielding gas, more than 20 kbar is usually required.

5. Water vapor in the furnace.

We must pay special attention to the steam in the furnace. There are two aspects: on the one hand, check whether the material of the furnace body is dry. If it is the first time to load the furnace, the material of the furnace body must be dry. On the other hand, stainless steel pipes can not leave too much water stains when entering the furnace. If there is an empty space, no water will leak in. Otherwise, water leakage will destroy the atmosphere in the furnace.