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close this bookAnnealing, Hardening, Tempering - Course: Working techniques of heat treatment of steel. Trainees' handbook of lessons (Institut für Berufliche Entwicklung, 27 p.)
View the document(introduction...)
View the documentIntroductory Remarks
View the documentHints on Labour Safety
View the document1. Objectives of Heat Treatment of Steel
View the document2. Kinds of Heat Treatment Processes
Open this folder and view contents3. Devices and Auxiliary Means
Open this folder and view contents4. Annealing
Open this folder and view contents5. Hardening
Open this folder and view contents6. Tempering
Open this folder and view contents7. Surface Hardening
View the document8. Hardening and Tempering

8. Hardening and Tempering

By this process, the strength of unalloyed steels with a carbon content of generally 0.2 to 0.6% in most cases can be changed in a wide range.

In spite of the low carbon content, those steels can reach higher strength values with higher toughness at the same time.


1. Heating of the material according to the hardening temperature in furnaces or melting baths between 700 °C to 860° C.

2. Quenching in water or oil to lukewarm.

3. Tempering according to the desired properties at temperatures between 360°C and 670°C and cooling down to lukewarm.

A high tempering temperature decreases the strength and increases the toughness!

Which properties shall be reached by hardening and tempering?