What is "nitriding"

n. A method of case hardening steel by the surface absorption of nitrogen by heating with ammonia.

Nitriding is a heat treating process that diffuses nitrogen into the surface of a metal to create a case-hardened surface. These processes are most commonly used on low-carbon, low-alloy steels. They are also used on medium and high-carbon steels, titanium, aluminium and molybdenum. In 2015, nitriding was used to generate unique duplex microstructure ( Martensite- Austenite, Austenite- ferrite), known to be associated with strongly enhanced mechanical properties

Typical applications include gears, crankshafts, camshafts, cam followers, valve parts, extruder screws, die-casting tools, forging dies, extrusion dies, firearm components, injectors and plastic- mold tools.