Parts are heated in a protective endothermic atmosphere to above the critical point of steel. Additions of methane and trim air are introduced and controlled via an oxygen probe. Parts will undergo a high carbon "boost" cycle followed by a lower carbon "diffuse" cycle for a determined time based on the desired case depth. Parts are then quenched in oil or polymer to harden and then are tempered. Case depths generally range from .015-.125 inches.
- Carburizing is frequently used on low carbon steels that need to have a hard outer surface. Due to the low carbon content of the steel, traditional quench and temper processing will not produce a hard surface. The diffusion of carbon into the steel allows for maximum surface hardness in excess of 60 HRC. With some alloy steels this allows for a hard wear resistant surface while retaining a high toughness core.
- Carburizing is generally used over carbonitriding in parts that have enough alloy content to not require nitrogen diffusion to increase the hardenability. This allows higher process temperatures and therefore shorter cycle times.
- AMS 2759/7
What To Consider When Specifying
- Case Depth
- Spec (if required)
- Masking (if required)
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