What are the factors that affect the annealing of stainless steel tube annealing furnace
Nov. 07, 2020
Factors affecting annealing of stainless steel tube annealing furnace
1. Whether the annealing temperature reaches the specified temperature
Stainless steel heat treatment generally adopts solution heat treatment, which is called "annealing", and the temperature range is about 1040-1120℃. You can also observe through the observation hole of the annealing furnace. The stainless steel tube in the annealing zone should be in an incandescent state, but there is no softening and sagging.
2. annealing atmosphere
Stainless steel tube annealing furnaces generally use pure hydrogen as the annealing atmosphere, and the purity of the atmosphere should be above 99.99% as much as possible. If the other part of the atmosphere is inert gas, the purity can also be lower, but it must not contain too much oxygen and water vapor.
3. furnace body tightness
The stainless steel tube annealing furnace should be closed and isolated from the outside air; if hydrogen is used as the protective gas, only one exhaust port is open. The method of inspection can be wiped with soapy water on the joints of the annealing furnace to see if it is out of gas.
The places where gas is easy to run out are the place where the annealing furnace enters the pipe and the place where the pipe exits. The sealing ring in this place is particularly easy to wear, and it should be checked and replaced frequently.
4. protective gas pressure
In order to prevent micro-leakage, the protective gas in the stainless steel tube annealing furnace should maintain a certain positive pressure. If it is hydrogen protective gas, it is generally required to be above 20kBar.
5. Steam in the furnace
On the one hand, check whether the furnace body material is dry. When installing the furnace for the first time, the furnace body material must be dried; on the other hand, whether excessive water stains remain on the stainless steel pipe entering the furnace, especially if there are holes on the pipe, do not leak water in. Otherwise, the atmosphere of the stove will be destroyed.
