Carburizing has been a popular method for obtaining a unique balance of properties in steels for many years. Steels with low carbon contents are characterized by good toughness and good ductility, but low strength and low wear resistance. By locally increasing the carbon content at the surface, followed by heat treatment to produce a very high hardness in this layer while maintaining a lower hardness in the core, the “best of both worlds” can be obtained a hard, wear-resistant surface with good fatigue strength and a tough, ductile core to inhibit the growth of any cracks that might form at the surface. Such a steel will be tougher than a through-hardened medium carbon content steel with the same surface hardness.
