Annealing temperature.


The annealing we often talk about is actually solution heat treatment of stainless steel. Whether the annealing temperature reaches the specified temperature will also affect the brightness of the stainless steel tube. We can observe through the annealing furnace that the stainless steel tube should normally be incandescent and not soften and sag.


 


Annealing atmosphere


Currently, 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 may be slightly lower. Must not contain too much oxygen and water vapor, otherwise it will greatly affect the brightness.


 


Furnace body seal


The tightness of the furnace body will also affect the brightness of the stainless steel tube. The annealing furnace is usually closed and isolated from the outside air. Hydrogen is usually used as a protective gas, and there is only one exhaust port for igniting the discharged hydrogen.


 


Shielding gas pressure


The protective gas pressure in the furnace must be maintained at a certain positive pressure to prevent micro-leakage.


 


Steam in the furnace


We must pay special attention to the water vapor in the stove. Check whether the material of the furnace body is dry.