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How To Anneal Butt Welding Flange
The shielding gas pressure of the butt welding flange is to avoid slight leakage of the butt welding flange. The shielding gas in the furnace should be connected to a certain positive pressure. Assuming that it is hydrogen shielding gas, it is generally required to be above 20kBar. Annealing air, butt welding flange generally uses pure hydrogen as annealing air, and the air purity is above 99.99%. If the other part of the air is an inert gas, the purity can be lower, but it cannot contain too much oxygen and water vapor.
Regardless of whether the annealing temperature in the butt welding flange reaches the specified temperature, the butt welding flange generally adopts solution heat treatment, which is generally called "annealing", and the temperature is planned to be 1040~1120℃. The survey can also be carried out through the survey hole of the process annealing furnace. Butt weld flange fittings in the annealed area should be incandescent, but not softened and sagging.
Butt welding flanges handle water vapor in foundry furnaces. On the one hand, check whether the furnace body material is dry, and the furnace body material needs to be dried for the first time. The second is whether there is too much water stains on the butt welding flange pipe fittings entering the furnace, especially if there are holes on the butt welding flange pipe fittings, do not leak water inside, otherwise the air in the furnace will be crushed.
The butt welding flange furnace is sealed, and the butt welding flange bright annealing furnace should be closed and isolated from the outside air; when hydrogen is used as a protective gas, an exhaust port is opened. The inspection method can be used to wipe the cracks in the joints of the annealing furnace with water to see if they run; the place where the gas leaks for a short time is the place where the annealing furnace enters the tube, and it is also the place where the tube exits. The wear of the sealing ring in this place is particularly short-lived and should be checked and replaced frequently.
hydrogen,Butt welding flange
There are four types of polishing methods for dual-phase steel flanges: manual, mechanical, chemical and electrochemical. The corrosion resistance and decoration of the flange can be improved by polishing. The existing stainless steel electropolishing solution still uses phosphoric acid and chromic anhydride. During the polishing and cleaning process, some chromium and phosphorus will be discharged into the waste water. pollution of the environment.
Welding spatter, iron filings, grease and other external impurities should be removed from the moving area of the probe. The flaw detection cousin should be flat and smooth to facilitate the free scanning of the probe. The surface roughness R.<6.3μm should be ground if necessary.
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