This group of thermal processes refers to a treatment where typically the surface layer has the requirement of a higher hardness which is typically more wear resistant than the core of material.
Flame hardening sometimes begins with a preheat operation depending on the alloy and degree of machining.
Certain processes, such as investment casting, create a decarburized layer on the surface of the part.
Certain processes, such as investment casting, create a decarburized layer on the surface of the part.
Gears made from plain carbon steels like 1017, 1018, and 1020 materials and low alloys such as 1117 & 12L14 require ammonia additions at the end of the carburizing process to increase the surface hardness of splines and teeth.