approx. 50 HRC after hardening and tempering
Fridolin Reiser has written: 'The hardening and tempering of steel' -- subject(s): Steel
mostly is the hardening done by induction hardening machine, I know also manufactures that do this using the flame hardening method.
en 45 is a silicon mangenese spring steel, supplied in the as rolled contition. This steel is suitable for oil hardening and tempering.
Case hardening, also referred to as surface hardening is the process of hardening a surface of a metal. It is done by surfacing the metal surface with a layer of metal on top of it, in order to harden it.
In short, heat treating is used to achieve the desired properties of the alloy such as hardening or softening. There are multiple methods used to do this, annealing, quenching, and tempering are a few.
because it removes the tempering(hardness) of the object, generally on the surface, and makes it easier to work the metal without ruining your tools or "work" hardening the surface.
Australia
The Tempering was created in 1983.
The Tempering has 198 pages.
The ISBN of The Tempering is 0-8991-9152-5.
Tempering