Fields of use

Quenched and tempered steels are used when excessive dimensions would result from the use of S235, S355 steels, etc. For all heavy-duty components in gears, engines, chassis, etc., e.g. gear wheels, crank shafts, engine shafts, screws, shift-forks, etc.

Description

Quenched and tempered steels are mechanical engineering steels, which are suitable for hardening due to their chemical composition and which have a very high level of toughness with a given tensile strength in their hardened and tempered state.
During the quenching and tempering procedure, the mechanical engineering steel receives the following combinations of properties: Higher yield stress Re, Rp0.2 for higher permitted strains and greater toughness (impact energy Av) for major deformation before the breakage. To achieve this toughness, the structure must not contain too much cementite. For this reason, the carbon contents are limited to 0.25 to 0.6%.

Properties

A selected combination between yield stress and toughness.
Welding: Not suitable (C35 and C45 can be welded to a degree).
Mechanical processing: Quenched and tempered steels can also be cut after the quenching and tempering process.

Product offers from Stahl-Contor from the Embrach service centre

&nb

Quenching and tempering

Quenching and tempering is a procedure involving the quenching of mechanical engineering steels with annealing at higher temperatures. Objective: Toughness with increased yield stress. Steels with increased yield stress with good toughness can be produced through two heat treatment procedures:

Quenching and tempering through annealing:
The quenching and tempering through annealing procedure is a hardening (martensitic structure) with subsequent annealing (heating) at temperatures between 450°C and 600°C, during which the maximum values are achieved with regards toughness and strength.
1. Quenching in water.
2. Hardening treatment (annealing), optimization of strength and toughness.

Quenching and tempering through isothermal conversion:
Quenching of an austenitic structure to a temperature between Ms (start of martensite formation) and Ar1 (holding point for cooling) and subsequent holding at this temperature (isothermal procedure). During this time, all the austenite is converted. Then the steel can be cooled to room temperature without any changes. This procedure is also known as austempering.