Carburizing and Hardening



Carburizing FurnaceCarburizing is a case 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. The result is a wear-resistant layer that makes the carburizing an ideal process in the production of strong, safe metals. 

What Are The Benefits of Carburizing?

Carburizing may also be referred to as case hardening. If this heat treatment process is done correctly, the surface metal on a carbon steel part will be more resistant to wear and the fatigue strength will be increased. Carburizing is commonly used in steel bearings and gears. Control of the carburizing heat treatment process is measured to industry specifications, enabling consistent process control batch after batch. In certain cases, alterations to the atmosphere can be made that may accelerate the carburizing speed and increase efficiency. A suspended carburizing process also eliminates the need for pusher furnaces to be emptied for weekend shutdowns — resulting in minimum delays and increased productivity.

Linde’s carburizing experts specialize in a variety of metals including low carbon and low alloy steels.

Precise, Reproducible, and Traceable Atmospheres (623KB)

Vacuum Carburizing

Carburizing Vacuum carburizing—also known as low pressure carburizing (LPC)—demands an atmosphere that is highly reproducible and highly controllable. The right carbon source for this process has been available for use since well before the vacuum heat treating process was developed. Linde’s nitrogen and methanol technology, combined with a precise atmosphere control system can provide ideal conditions for better control and repeatability.

Chemical Acetylene for Vacuum Carburizing (583KB)


Ferrous metals are normally hardened by heating to a required temperature. The metal is then cooled rapidly in a quenching medium, such as oil, water, or brine. This process increases the hardness and strength of the metal. Neutral hardening and tempering produce strength and toughness on parts that will be highly stressed. 

Case hardening is an ideal heat treatment for parts which require a wear-resistant surface and a tough core, such as gears.

Learn more about materials processing applications

Contact us to learn more about carburizing and other heat treatment applications.