Quench and Temper

Hardening by rapid cooling from austenitising temperature, then tempering back to the ordered strength and toughness.

Quenching forms martensite, which is hard and brittle and carries high residual stress; tempering between about 540 and 680 °C trades some strength back for toughness and relieves that stress. The property class quoted on the order — say 800 MPa yield with 45 J at −40 °C — is achieved by choosing the tempering temperature, which is why the furnace chart is part of the certificate rather than an internal record.

Related terms

Normalising
Hardenability
Stress Relief

Where this applies

forged-shafts, open-die-forgings

Need help applying this?

Stancor Forgings engineers answer specification questions directly. Contact us.