Options In Case Hardening Processes In Pennsylvania
As the name implies, the process of case hardening is designed to create a protective case or shell on the outside of a metal part or component. At the same time, the process does not extend any deeper than required into the surface of the metal, preventing any change in the physical property of the underlying metal.
The result of this process is a hard, even layer or case on the outside, without any need to further treat the metal to soften as would be the case with quenching types of processes. Without the need to complete additional processes the cost of production is kept low, making it an ideal option for many Pennsylvania OEMs.
In most cases, the process of case hardening is done as a final step in the production of the part or component. This means after the part is formed, allowing the hard case to be set specifically to the exact tolerance required with no concerns about how forming or shaping of the piece may impact the case.
When a Pennsylvania OEM looks at using case hardening, there are several processes to consider. Each offers distinctive benefits for specific types of metals and applications.
- Induction hardening – often used for complex parts, the use of induction heating provides specific temperature changes on the exact surface locations required. After heating to the specific temperature, the surface is cooled rapidly.
- Nitriding – this process heats the steel part to a specific temperature in an environment with ammonia. The time is controlled to manage the depth of the surface nitrides that form to create the protective layer.
- Carburizing – similar to nitriding, this uses a carbon-rich environment where the steel is heated and held and then quenched. The steel must have at least 0.1 to 0.3 wt% of carbon and the time held at temperature determines the thickness of the case.
There are other options for this hardening process as well. These include carbonitriding, cyaniding and ferritic nitrocarburizing.