Definition - What does Tempering mean?
Tempering is the process of treating metals through heating in order to enhance toughness. This is primarily applicable in alloys that are iron based. It is typically performed post-hardening to reduce extra hardness, which can be accomplished by subjecting metal to a temperature under the critical temperature within a particular time period.
This process is highly beneficial in corrosion control, as the use of intense heat gives off various properties of softness or hardness depending on the levels of carbon in the steel.
Corrosionpedia explains Tempering
Tempering is a technique that involves the use of heat to strengthen metals. This can be applied to almost all forms of ferrous alloys like cast iron and steel. With this process, these metals could achieve higher levels of toughness through the reduction of hardness.
Decreasing the hardness of an alloy typically causes enhanced ductility, reducing the metal’s brittleness. Tempering is typically done post-quenching, in order to achieve ultimate hardness. This process is completed by controlling the heat of the quenched metal below the critical temperature.
Tempering is mostly applied in steel with high carbon levels since these are the only materials allowed for tempering. It is a vital process since, when steel undergoes heating to the point where it glows red and is then immediately cleaned in water, it can become too hard and brittle.
When the steel is allowed to cool very slowly, the result is steel that is more ductile, stronger, easier to file, cut and shape. It can also be more resistant to corrosion.