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Fig. 6. 4 Pack carburization

Gas Carburization

Process description
Gas carburization shares similarities with pack carburization, necessitating the pumping of carbon
monoxide. The difference is that it doesn't necessitate the presence of carbon-dense items.
In this process, carbon monoxide is continuously pumped into an enclosed environment. This
environment is heated at extremely high temperatures. High temperatures allow carbon molecules to
diffuse into the steel items which are being hard cased (Fig. 6. 5). 2

Benefits
It's simple: steel which has been carburized will have a very hard exterior. This allows it to take on a
great deal of physical trauma without wearing down prematurely. Another major benefit of carburized
steel is that it possesses a soft interior. Because it possesses a soft interior, it's easy to manipulate into
different shapes. This makes it especially useful for when you're trying to manufacture intricate metal
items with hard surfaces (ie. internal machine components).

Application
Carburizing is generally applied to unalloyed or low alloyed steels with a composition of less than 0.2%
carbon. These steels are called ‘’cementation steels’’. Carburizing steels; gears, shafts, piston pins,
valves, chain links, sprockets, discs, roller bearings, some parts such as measuring and control

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Fig. 6. 5 Gas carbuzing chamber

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