Nitriditeräkset

Nitriditeräkset, also known as nitrided steels, are a category of steel alloys that undergo a case hardening process called nitriding. This process involves diffusing nitrogen into the surface of the steel at elevated temperatures, typically between 495 and 565 degrees Celsius, in a nitrogen-rich atmosphere. The presence of nitrogen in the steel's surface layer forms hard iron nitrides.

The primary benefit of nitriding is the creation of a very hard, wear-resistant surface layer while maintaining a relatively tough core. This makes nitrided steels ideal for applications where high surface hardness and resistance to abrasion are critical. Common applications include gears, crankshafts, camshafts, dies, and cutting tools.

The composition of nitriding steels is important. They generally contain alloying elements such as aluminum, chromium, molybdenum, and vanadium. These elements readily form stable nitrides, enhancing the hardness and wear resistance of the nitrided case. Aluminum is particularly effective as it forms hard aluminum nitrides.

Nitriding can be performed in various ways, including gas nitriding, salt bath nitriding, and plasma nitriding. Each method has its own advantages and disadvantages regarding process control, achievable case depth, and cost. The resulting surface is often characterized by a compound layer, a diffusion zone, and the core material. The compound layer, typically rich in iron nitrides, provides excellent wear resistance and corrosion resistance, though it can be brittle. The diffusion zone below it offers a gradual transition in hardness.