There are more and more applications of stainless steel seamless pipes, and it can be seen everywhere. There are many manufacturers of stainless steel seamless pipes, and the quality of stainless steel seamless pipes has become the focus of attention. The brightness of stainless steel seamless pipe after annealing determines the quality of the product. There are also many factors that affect the brightness of seamless steel pipes. Five important factors are listed for readers' reference only.

1. Whether the annealing temperature reaches the specified temperature.

Stainless steel heat treatment is generally taken solution heat treatment, which is commonly known as "annealing", the temperature range of 1120 ℃ (Japanese standards). You can also observe through the annealing furnace observation hole, the annealing zone of the stainless steel tube should be incandescent state, but did not appear softening sag.

2. Annealing atmosphere. 

Generally are used pure hydrogen as the annealing atmosphere, the atmosphere purity good is more than 99.99%, if another part of the atmosphere is inert gas, the purity can also be a little lower, but can not contain too much oxygen, water vapor.

3. Furnace sealing.

Bright annealing furnace should be closed, isolated from outside air; using hydrogen as a protective gas, only one exhaust port is through (used to ignite the discharge of hydrogen gas). Check the method can be wiped with soapy water in the annealing furnace at each joint gap, to see whether the runaway gas; which easy to runaway gas is the annealing furnace into the place where the tube and out of the tube, the seal in this place is particularly easy to wear, to often check often change.

4. Protective gas pressure. 

In order to prevent micro-leakage, the furnace protective gas should be maintained at a certain positive pressure, if it is hydrogen protective gas, the general requirements of more than 20kBar.

5. Water vapor in the furnace. 

On the one hand, check whether the furnace material is dry. When the furnace is installed for the first time, the furnace material must be dry; second, whether there is too much water stain left in the stainless steel pipe entering the furnace, especially if there are holes on the pipe, do not leak water, otherwise The atmosphere in the entire furnace was destroyed.