Case-hardening is a heat treatment process that hardens the outer surface of a metal, like steel, while keeping the interior soft and tough. This combination of properties makes the metal resistant to wear on the outside and prevents it from shattering under impact on the inside. The process involves heating the metal in a carbon-rich environment, a technique called carburization, and then quenching it.
Key aspects of case-hardening
Protective outer layer: The "case" is a thin, hard surface layer created by infusing carbon into the metal.
Tough core: The core of the metal remains soft, which provides toughness and resistance to fracture.
Purpose: It is used for parts that require a hard surface for wear resistance, but also need to withstand significant impact, such as gears.
Cost-effective: It can be more cost-effective than using high-carbon steel for parts that only require a hard surface
