Carburizing is used as a continuous process for high volume surface hardening. Carburising is suited well for medium to low carbon steels, carburizing improves durability and used mainly to the materials like Low carbon alloy steels, Low carbon steels and etc.
Carburization is a process which involves taking low carbon steel and transforming it into high carbon steel. It will be carried out by exposing it to an atmosphere which is dense in carbon.
Carburizing is a case of the hardening process in which carbon diffuses into the surface layer of a steel part at a temperature high enough to change the steel grain structure. This change enables the steel to absorb carbon. There are three types of carburising based on the carbon source: solid carburizing, liquid carburizing, and gas carburizing.
Gas carburizing furnaces are either gas-fired or electrically heated which will be carried out at a temperature range of 900 to 950 °C. It consistently produces uniformly-carburized steel and involves heating carbon steel to austenitizing temperature in the presence of a carbon-rich atmosphere.
The component is held in furnace that contains an atmosphere of methane or propane with a neutral carrier gas, usually a mixture of N2, CO, CO2, H2, and CH4. At the carburizing temperature, methane (or propane) decomposes on the component surface to atomic carbon and hydrogen, with the carbon diffusing into the surface. The quenching medium will be oil, water, or polymer.