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What are the conditions for bright annealing of 316 stainless steel welded pipe?

What are the conditions for bright annealing of 316 stainless steel welded pipe?

Time:2022-03-18 Source:China Wuxi JiaNuo Special Steel Co.

316 stainless steel welded pipe in order to reduce the hardness, eliminate residual stress, stabilize the size, reduce the tendency of deformation and cracking, and eliminate organizational defects, the stainless steel welded pipe bright annealing, in annealing need to meet the five conditions.

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316 stainless steel pipe bright annealing requires five major conditions

1, the furnace body sealing is good. Bright annealing furnace is preferably closed and isolated from the outside air; if hydrogen is used as the maintenance gas, only an exhaust port is required.

2, Water vapor inside the furnace. On the one hand, check whether the furnace data is present and not boring, and secondly, whether there is excessive water damage to the stainless steel tube entering the furnace.

 

3, maintain the air pressure. To avoid the appearance of micro-leaks, the maintenance gas in the furnace should adhere to a certain positive pressure. If it is hydrogen maintenance gas, usually need to exceed 20kBar.

4, whether the annealing temperature reaches room temperature. Solution heat treatment is usually used in stainless steel heat treatment, usually called “annealing”, the temperature range of 1040 ~ 1120 ℃. You can also study the hole through the annealing furnace. The annealed area of the stainless steel tube should be in the incandescent state, but there will be no softening and sagging phenomenon.

5, annealing atmosphere. Stainless steel tube annealing atmosphere is mainly selected from pure hydrogen. Therefore, the purity of the atmosphere is infinitely close to 100%. It is certainly not rich in excess oxygen and water vapor, because the atmosphere is the main reason for the quality of stainless steel pipe.