Quenching and tempering are processes that strengthen and harden materials like steel and other iron-based alloys. The process of quenching or quench hardening involves heating the material and then rapidly cooling in water, oil, forced air or inert gases such as nitrogen.
Thereof, what kind of oil is used to quench steel?
Oil is the most commonly used quench liquid especially if you are unsure of the exact chemical composition of your steel. Common oils used are vegetable, mineral, cottonseed or whale oil. Oil cools the steel more slowly than water which makes it less prone to cracking but hardens just as much as water.
What is hardened steel used for?
The term hardened steel is often used for a medium or high carbon steel that has been given heat treatment and then quenching followed by tempering. The quenching results in the formation of metastable martensite, the fraction of which is reduced to the desired amount during tempering.
Why are steels tempered after quenching?
Tempering is a heat treatment technique applied to ferrous alloys, such as steel or cast iron, to achieve greater toughness by decreasing the hardness of the alloy. Tempering is usually performed after quenching, which is rapid cooling of the metal to put it in its hardest state.