Hardening and tempering

The materials are heated to the austenite area before cooling and kept for a certain period of time.

This neutral hardening process, which is the oldest heat treatment, rapidly cools the part heated in a protective (inert gas) or non-protective (air) atmosphere.

The cooling medium can be water, oil, polymer, hot bath, compressed gas and air.

This process, which is often referred to as Quench and Temper (QT) in technical drawings in English, has entered Turkish as tempering.

At the end of this process, the expected structure in the steel material is martensite. Martensite, a metastable phase, is brittle and brittle. The process performed to reduce this brittleness and bring the hardness to the desired level is called tempering.

Materials with more than 0.20% carbon may harden.

CQI-9 Table A is used for this heat treatment technique in the automotive industry.