Quenched and Tempered (+QT) 1.1221 Steel
EN 1.1221 +QT steel is EN 1.1221 steel in the quenched and tempered condition. It has the highest strength compared to the other variants of EN 1.1221 steel. The graph bars on the material properties cards below compare EN 1.1221 +QT steel to: wrought carbon or non-alloy steels (top), all iron alloys (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.
Mechanical Properties
Brinell Hardness
250
Elastic (Young's, Tensile) Modulus
190 GPa 27 x 106 psi
Elongation at Break
12 %
Fatigue Strength
340 MPa 50 x 103 psi
Poisson's Ratio
0.29
Rockwell C Hardness
64
Shear Modulus
72 GPa 10 x 106 psi
Shear Strength
520 MPa 76 x 103 psi
Tensile Strength: Ultimate (UTS)
870 MPa 130 x 103 psi
Tensile Strength: Yield (Proof)
550 MPa 79 x 103 psi
Thermal Properties
Latent Heat of Fusion
250 J/g
Maximum Temperature: Mechanical
400 °C 750 °F
Melting Completion (Liquidus)
1460 °C 2650 °F
Melting Onset (Solidus)
1410 °C 2580 °F
Specific Heat Capacity
470 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
48 W/m-K 28 BTU/h-ft-°F
Thermal Expansion
12 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
7.2 % IACS
Electrical Conductivity: Equal Weight (Specific)
8.3 % IACS
Otherwise Unclassified Properties
Base Metal Price
2.1 % relative
Density
7.8 g/cm3 490 lb/ft3
Embodied Carbon
1.5 kg CO2/kg material
Embodied Energy
19 MJ/kg 8.2 x 103 BTU/lb
Embodied Water
47 L/kg 5.6 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
95 MJ/m3
Resilience: Unit (Modulus of Resilience)
800 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
31 points
Strength to Weight: Bending
26 points
Thermal Diffusivity
13 mm2/s
Thermal Shock Resistance
28 points
Alloy Composition
| Fe | 97.1 to 98.8 | |
| Mn | 0.6 to 0.9 | |
| C | 0.57 to 0.65 | |
| Si | 0 to 0.4 | |
| Cr | 0 to 0.4 | |
| Ni | 0 to 0.4 | |
| Mo | 0 to 0.1 | |
| P | 0 to 0.035 | |
| S | 0 to 0.035 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Further Reading
EN 10250-2: Open die steel forgings for general engineering purposes - Part 2: Non-alloy quality and special steels
EN 10297-1: Seamless circular steel tubes for mechanical and general engineering purposes - Technical delivery conditions - Part 1: Non-alloy and alloy steel tubes
Microstructure of Steels and Cast Irons, Madeleine Durand-Charre, 2004
Carbon Steel Handbook, D. Gandy, 2007
ASM Specialty Handbook: Carbon and Alloy Steels, J. R. Davis (editor), 1996
Ferrous Materials: Steel and Cast Iron, Hans Berns and Werner Theisen, 2008
Steels: Processing, Structure, and Performance, 2nd ed., George Krauss, 2015