The Rostec State Corporation has shown the process of surface hardening of aircraft screws made of alloy steels using ion nitriding technology. The procedure is carried out in the heat treatment shop.
The technological process involves the formation of a nitrided layer on the surface of the product, which improves its characteristics.
The screws used in the aircraft control systems are loaded into a special ion nitriding furnace. Ammonia is supplied through a dissociator flask installed in it, which decomposes into nitrogen and hydrogen at a temperature of 850°C. In the chamber with the screws, under the influence of gas and temperature, a surface nitrided layer with a thickness of 0.3 - 0.55 mm is created on the parts. This takes 24 - 30 hours.
During assembly, special hardened nuts are used, which are put on the screws. They are equipped with balls inside, which allows them to move easily along the grooves of the screw. The nitrided layer on the nuts and screws prevents them from wearing out.
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