Skip Navigation

Unalloyed and alloyed quenched and tempered steels – high strength and ductility after hardening for highly stressed components

Seat back adjustment with sprocket made of alloyed quenched and tempered steel.

Quenched and tempered steels include unalloyed or alloyed structural steels, which are suitable for quenching and tempering due to their chemical composition. Their maximum hardness mainly depends on the carbon content.

The carbon content of quenched and tempered steels generally ranges between 0.17 and 0.65%. Alloyed quenched and tempered steels also contain chromium, manganese, molybdenum and/or nickel to obtain the desired properties. Alloyed quenched and tempered steels also include boron-alloyed QT steels: manganese-boron steels and boron steels TBL and TBL Plus. Quenched and tempered steels are standardized in DIN EN ISO 683 Part 1 and 2 (previously DIN EN 10083, Parts 1 to 3), and in DIN EN 10132, Part 3, which covers cold-rolled strip.

QT steels are intended for heat treatment, which involves quenchhardening and tempering. In the quenchhardening process, the maximum hardness level corresponding to the carbon content is reached; during the subsequent tempering process, the hardness is reduced again to obtain an optimum combination of hardness and ductility.

Fields of application of unalloyed and alloyed quenched and tempered steels

Circular saw blade made of hot-rolled alloyed quenched and tempered steel.
Circular saw blade made of hot-rolled alloyed quenched and tempered steel.

The unalloyed quenched and tempered steels are used for lower loads, whereas the alloyed quenched and tempered steels are suited for high dynamic and static loads. Moreover, the strength and ductility requirements are decisive for the selection of steel grades; the component dimensions must also be taken into account. In many fields of application, the focus is on the maximum possible full quenching and tempering.

There are various fields of application of QT steels: typical applications in vehicle construction are camshafts and transmission shafts, axles, clutch components and fastening elements. In mechanical and plant engineering, quenched and tempered steels are used, for example, in shafts, pinions, gear wheels, chain links and saw blades.

thyssenkrupp supplies the following steel grades as per the product information or the reference steel grades in accordance with the respective standards.

Unalloyed quenched and tempered steel according to DIN EN ISO 683-1 (previously DIN EN 10083-2), DIN EN 10132-3

Steel grade designation Reference grade Material no. THICKNESS1
from _ to in mm
WIDTH1
from _ to in mm
C22 C22 1.1151 2.00 – 13.00 50 – 1,630
C25 C25 1.1158 2.00 – 13.00 50 – 1,630
C35 C35 1.1181 2.00 – 13.00 50 – 1,630
C40 C40 1.1186 2.00 – 13.00 50 – 1,630
C45 C45 1.1191 2.00 – 13.00 50 – 1,630
C50 C50 1.1206 2.00 – 13.00 50 – 1,630
C55 C55 1.1203 2.00 – 13.00 50 – 1,630
C60 C60 1.1221 2.00 – 13.00 50 – 1,630
1. Not all thickness and width combinations possible.

Chemical composition of unalloyed quenched and tempered steel

Steel grade C [%]
Si [%] ­max. Mn [%]
P [%] ­max. S [%] ­max. Cr [%] ­max. Mo [%] ­max. Ni [%] ­max. Cr + Mo +Ni [%]­max.
C22 0.17 – 0.24 0.40 0.40 – 0.70 0.025 0.010 0.40 0.10 0.40 0.63
C25 0.22 – 0.29 0.40 0.40 – 0.70 0.025 0.010 0.40 0.10 0.40 0.63
C35 0.32 – 0.39 0.40 0.50 – 0.80 0.025 0.010 0.40 0.10 0.40 0.63
C40 0.37 – 0.44 0.40 0.50 – 0.80 0.025 0.010 0.40 0.10 0.40 0.63
C45 0.42 – 0.50 0.40 0.50 – 0.80 0.025 0.010 0.40 0.10 0.40 0.63
C50 0.47 – 0.55 0.40 0.60 – 0.90 0.025 0.010 0.40 0.10 0.40 0.63
C55 0.52 – 0.60 0.40 0.60 – 0.90 0.025 0.010 0.40 0.10 0.40 0.63
C60 0.57 – 0.65 0.40 0.60 – 0.90 0.025 0.010 0.40 0.10 0.40 0.63
Mass fractions in ladle analysis.

Alloyed quenched and tempered steel according to DIN EN ISO 683-2 (previously DIN EN 10083-1 and DIN EN 10083-3), DIN EN 10132-3

Steel grade designation Reference grade Material no. THICKNESS1
from _ to in mm
WIDTH1
from _ to in mm
34CrMo4 34CrMo4 1.7220 2.00 – 13.00 100 – 1,630
42CrMo4 42CrMo4 1.7225 2.00 – 13.00 100 – 1,630
50CrMo4 50CrMo4 1.228 2.00 – 13.00 100 – 1,630
51CrV4 51CrV4 1.8159 2.00 – 13.00 100 – 1,630
58CrV4 Special mill grade 1.8161 2.00 – 13.00 100 – 1,630
1. Not all thickness and width combinations possible.

Chemical composition of alloyed quenched and tempered steel

Steel grade C [%]
Si [%]
max.
Mn [%]
P [%]
max.
S [%]
max.
Cr [%]
Mo [%] ­max. / - V [%] B [%]
34CrMo4 0,30 – 0,37 0,40 0,60 – 0,90 0,025 0,010 0,90 – 1,20 0,15 – 1,30
42CrMo4 0,38 – 0,45 0,40 0,60 – 0,90 0,025 0,010 0,90 – 1,20 0,15 – 1,30
50CrMo4 0,46 – 0,54 0,40 0,50 – 0,80 0,025 0,010 0,90 – 1,20 0,15 – 1,30
51CrV4 0,47 – 0,55 0,40 0,70 – 1,10 0,025 0,010 0,90 – 1,20 0,10 0,10 – 0,25
58CrV4 0,54 – 0,62 0,40 0,70 – 1,10 0,025 0,010 0,90 – 1,20 0,10 – 0,20
Mass fractions in ladle analysis.
To the top