Stainless Steel Weld Fittings The brightness of the product after annealing determines the quality of the product. There are many factors that affect its brightness. Here are the five most important factors:

1. Whether the annealing temperature reaches the specified temperature. The heat treatment of stainless steel pipe fittings generally adopts solid solution heat treatment, which is what people usually call "annealing". The temperature range is 1040~1120 degrees (Japanese standard). You can also observe through the observation hole of the annealing furnace. The stainless steel pipe fittings in the annealing area should be in an incandescent state, but there is no softening and hanging.

2. The annealing atmosphere generally uses pure hydrogen as the annealing atmosphere. The purity of the atmosphere is preferably above 99.99%. If another part of the atmosphere is an inert gas, the purity can be lower, but it must not contain too much oxygen and water vapor.

3. The sealing of the furnace body. The bright annealing furnace should be closed and isolated from the outside air; if hydrogen is used as a protective gas, only one exhaust port is open (used to ignite the discharged hydrogen). The inspection method is to use soapy water to wipe the gaps of each joint of the annealing furnace to see if there is any gas leakage; the most likely place for gas leakage is the place where the annealing furnace enters and exits the pipe. The sealing rings in this place are particularly easy to wear and tear, so they should be checked and replaced frequently.

4. Protective gas pressure In order to prevent micro-leakage, the protective gas in the furnace should maintain a certain positive pressure. If it is hydrogen protective gas, it is generally required to be above 20kBar.

5. Water vapor in the furnace On the one hand, check whether the furnace body material is dry. When the furnace is first installed, the furnace body material must be dried; second, whether there is too much water stains on the stainless steel pipe entering the furnace, especially if there are holes on the pipe, do not let water leak in, otherwise the furnace atmosphere will be completely destroyed. Generally, if it is normal, the stainless steel pipe that should be retreated about 20 meters after the furnace is opened will begin to shine, the kind that is bright and reflective. The most important thing to pay attention to is the knowledge we mentioned above. I hope everyone can pay attention to it during production.