Definition
A surface-hardening process in which nitrogen is diffused into the surface of a steel part at elevated temperature to form a thin, extremely hard, wear-resistant case. In aviation, nitriding is most commonly applied to engine cylinder walls and crankshaft journals to extend service life and resist scuffing.
Plain English
A way of treating the outside of a steel part so that its surface becomes very hard and resists wear, while the inside stays tougher and more flexible. It works by soaking the part in nitrogen-rich gas while it's hot, letting the nitrogen sink into the surface.
Context Anchor
Seen in aircraft maintenance and materials discussions, especially when describing hardened steel parts in engines or landing gear components.
Derivation
From 'nitrogen,' the element used in the process. The '-ide' ending in chemistry indicates a compound formed with that element — here, nitrogen compounds formed in the surface layer of the steel.
Why Pilots Care
Nitriding extends the service life of critical rotating parts such as crankshafts and camshafts, reducing the risk of premature failure under operational stresses.
Intuition Check
A nitride is not just a coating painted onto a part. It is a nitrogen-based compound formed in or on the material itself.
Example Sentence 1
The cylinder barrels on this engine are nitrided, so they should not be honed with abrasive material that could damage the hardened surface.
Example Sentence 2
Nitride layers can spall if the heat treatment process is not controlled correctly, leading to accelerated wear.