1.Sealing of furnace body
The bright annealing furnace of stainless steel welded pipe should be closed and isolated from the outside air. Only one vent can be used to protect hydrogen gas (used to ignite the discharged hydrogen). The method of inspection is to apply soap water to the joints of the annealing furnace to see if there is air leakage. The most easily leaking place is the place where the annealing furnace enters the pipe and where the pipe is discharged. The seal ring in this area is easy to wear, so it should be checked regularly.
2. Annealing atmosphere
Generally, pure hydrogen is used as the annealing atmosphere for stainless steel welded pipe. The purity of the atmosphere is best over 99.99%. If the other part of the atmosphere is inert gas, the purity can also be lower, but absolutely can not contain too much oxygen and water vapor.
3. whether the annealing temperature reaches the required temperature.
Stainless steel heat treatment is usually treated by solid solution heat treatment, which is commonly referred to as "annealing", with a temperature range of 1.04k~1.12k degrees. You can also observe through the observation hole of the annealing furnace. The stainless steel tube in the annealing area should be incandescent, but there is no softening droop.
4. Protective gas pressure.
In order to prevent micro leakage, the protective gas in the furnace must be kept at a positive pressure. If it is a hydrogen gas, it usually requires more than 20000Bar.
5. Water vapor in the furnace
On the one hand, check whether the material of the furnace is dry. For the first time, the furnace material must be dried. The two is whether there is too much water stains in the stainless steel welded pipe of the furnace. If there is a hole on the top of the pipe, do not leak in, otherwise the furnace atmosphere will be completely destroyed. It should be noted that basically these are, normally, the stainless steel tubes that should be retreated for about 20 meters after starting the furnace will start to shine and shine.