Nitrocarburising is a variation of the case hardening process. It is a thermochemical diffusion process where nitrogen, carbon, and to a very small degree, oxygen atoms diffuse into the surface of the steel part, forming a compound layer at the surface, and a diffusion layer. Nitrocarburising is a shallow case variation of the nitriding process. This process is done mainly to provide an anti-wear resistance on the surface layer and to improve fatigue resistance.
Benefits of nitrocarburising
-Relative low cost;
-High resistance to wear;
-Excellent scuffing and seizure resistance;
-Fatigue properties improved by up to 120%;
-Considerably improved corrosion resistance;
-Good surface finish;
-Negligible shape distortion;
-Predictable growth characteristics; and
-Alloy substitution – plain carbon steels replacing low alloy steels.
Application & materials
Advantages of the process include the ability to harden materials which are not pre-hardened, the relatively low temperature of the process which minimises distortion, and relative low cost in comparison to carburising or other case hardening processes.
Typical industries:
Oil and gas, valve, pump, agriculture equipment, automotive, stamping, textile, extrusion and injection moulding, and firearms components.
Typical parts:
-Oil and gas – gears and pinion shafts
-Valve components – gates, seats, balls, stems, regulator valves
-Pump components – impellor housings, bodies, plungers, cylinders
-Agriculture equipment – harvesting combine cutters, separators, crop transfer, chopping components
-Automotive – diesel engine oil pumps, gears, crankshafts and camshafts