Gas nitriding involves heating steel components to 500-580°C in a controlled ammonia atmosphere. At this temperature, ammonia dissociates on the steel surface, releasing nascent nitrogen atoms that diffuse into the surface layer. The nitrogen atoms combine with alloying elements (Cr, Mo, Al, V) in the steel to form hard nitride compounds, creating a wear-resistant case without dimensional distortion. The furnace maintains precise control over temperature (±2°C), ammonia flow rate, and dissociation percentage (typically 15-35%) to achieve the desired case depth and hardness profile. The process requires no quenching, eliminating distortion and cracking risks, making it ideal for finished components.