EN 1.5501 (15B2) Boron Steel
EN 1.5501 steel is an alloy steel formulated for primary forming into wrought products. 1.5501 is the EN numeric designation for this material. 15B2 is the EN chemical designation.
It has a very low base cost among EN wrought alloy steels. In addition, it has a very low electrical conductivity and can have the lowest tensile strength.
The properties of EN 1.5501 steel include four common variations. This page shows summary ranges across all of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare EN 1.5501 steel to: EN wrought 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
120 to 150
Elastic (Young's, Tensile) Modulus
190 GPa 27 x 106 psi
Elongation at Break
12 to 17 %
Fatigue Strength
180 to 270 MPa 26 to 40 x 103 psi
Poisson's Ratio
0.29
Reduction in Area
63 to 73 %
Shear Modulus
73 GPa 11 x 106 psi
Shear Strength
270 to 310 MPa 38 to 45 x 103 psi
Tensile Strength: Ultimate (UTS)
390 to 510 MPa 56 to 74 x 103 psi
Tensile Strength: Yield (Proof)
260 to 420 MPa 38 to 60 x 103 psi
Thermal Properties
Latent Heat of Fusion
250 J/g
Maximum Temperature: Mechanical
400 °C 750 °F
Melting Completion (Liquidus)
1460 °C 2670 °F
Melting Onset (Solidus)
1420 °C 2590 °F
Specific Heat Capacity
470 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
52 W/m-K 30 BTU/h-ft-°F
Thermal Expansion
13 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
7.0 % IACS
Electrical Conductivity: Equal Weight (Specific)
8.1 % IACS
Otherwise Unclassified Properties
Base Metal Price
1.8 % relative
Density
7.9 g/cm3 490 lb/ft3
Embodied Carbon
1.4 kg CO2/kg material
Embodied Energy
18 MJ/kg 7.9 x 103 BTU/lb
Embodied Water
46 L/kg 5.5 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
40 to 83 MJ/m3
Resilience: Unit (Modulus of Resilience)
190 to 460 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
14 to 18 points
Strength to Weight: Bending
15 to 18 points
Thermal Diffusivity
14 mm2/s
Thermal Shock Resistance
11 to 15 points
Alloy Composition
Among alloy steels, the composition of EN 1.5501 steel is notable for including boron (B). Boron is used to improve hardenability. It has a substantial effect when added in even tiny amounts.
| Fe | 98.4 to 99.269 | |
| Mn | 0.6 to 0.8 | |
| Si | 0 to 0.3 | |
| C | 0.13 to 0.16 | |
| Cu | 0 to 0.25 | |
| P | 0 to 0.025 | |
| S | 0 to 0.025 | |
| B | 0.00080 to 0.0050 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
Boron in Steel, S. K. Banerji and J. E. Morral (editors), 1980
EN 10263-3: Steel rod, bars and wire for cold heading and cold extrusion - Part 3: Technical delivery conditions for case hardening steels
Microstructure of Steels and Cast Irons, Madeleine Durand-Charre, 2004
Manufacture and Uses of Alloy Steels, Henry D. Hibbard, 2005
Ferrous Materials: Steel and Cast Iron, Hans Berns and Werner Theisen, 2008
CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015
Steels: Processing, Structure, and Performance, 2nd ed., George Krauss, 2015