During the manufacturing process of stainless steel seamless elbows, some operational errors may affect their quality and even service life. Let’s see what they are!
1. The temperature in the furnace does not meet the regulations
The raw material of the stainless steel seamless elbow is a round tube billet. During manufacturing, the tube billet needs to be sent to the furnace for heating at a temperature of about 1200℃, and the flange pipe fittings are solid solution treated at a range of about 1040-1120℃. If the temperature in the furnace during the manufacturing of the stainless steel seamless elbow does not meet the regulations, it may affect the quality.
2. Improper fuel selection
When the round tube billet is heated, fuel (hydrogen or acetylene) needs to be added. Hydrogen is usually pure hydrogen, and the atmosphere purity is preferably above 99.99%. If the other part of the atmosphere is an inert gas, the purity may be reduced, and the stainless steel seamless elbow produced is easy to become brittle and easy to be damaged or leaked under high temperature, high pressure and other conditions.
3. The protective gas pressure in the furnace is incorrect
In order to prevent small leaks in the stainless steel seamless elbow, the protective gas in the furnace should maintain a certain positive pressure.
4. The sealing of the furnace is not good
The bright annealing furnace should be closed and isolated from the outside air.
If hydrogen is used as the shielding gas, only one exhaust port needs to be opened.