Annealing is a heat treatment process in the processing of stainless steel pipe fittings. The pipe is slowly heated to a certain temperature for a sufficient period of time and then cooled at a suitable speed.
The brightness of the product after the production of stainless steel pipe fittings determines the quality of the product. The process of annealing in the stainless steel market is quite mature. The following three advantages of stainless steel affect the brightness of stainless steel in actual production:
1. Whether the annealing temperature reaches the specified temperature, the heat treatment of stainless steel pipe fittings is generally carried out by solid solution heat treatment, which is commonly called “annealing”, and 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 zone should be in an incandescent state, but the softening spreader does not sag.
2. The annealing atmosphere generally uses pure hydrogen as the annealing atmosphere, and the purity of the atmosphere is preferably 99.99% or more. If another part of the atmosphere is an inert gas, the purity can be lower, but it must not contain too much oxygen or water vapor.
3. The furnace sealing bright annealing furnace should be closed and isolated from the outside air; using hydrogen as the shielding gas, only one exhaust port is open (used to ignite the discharged hydrogen). The method of inspection can be applied to the gaps of the joints of the annealing furnace with soapy water to see if the gas is running. The most easy place to run the gas is the place where the annealing furnace enters the pipe and the place where the pipe is discharged. The sealing ring in this place is particularly prone to wear. Always check frequently to change.
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 generally requires more than 20kbar.
5. In the furnace, the water vapor on the one hand checks whether the material of the furnace body is dry. When the furnace is first installed, the material of the furnace body must be dried. Second, whether the stainless steel pipe entering the furnace has excessive water stains, especially if there is a hole in the pipe, Don’t leak into it, or else destroy the atmosphere of the stove. Generally, if it is normal, the stainless steel pipe that should be retreated 20 meters after opening the furnace will start to brighten, and the kind that is reflective. The most important thing to note is the knowledge we mentioned above. I hope everyone is producing. You can pay attention when you are….
Source: China Stainless Steel Pipe Fittings Manufacturer – Yaang Pipe Industry Co., Limited (www.yaang.com)