United Kingdom · B.S.

722 M 24

BS PD 970:2005 — Wrought steels for mechanical and allied engineering purposes. Requirements for carbon, carbon manganese and alloy hot worked or cold finished steels

Chemical composition

wt% · log scale
0.010.1110C0.2 – 0.28Cr3 – 3.5Mn0.45 – 0.7Mo0.45 – 0.65Other0.12
  • min – max range
  • typical value

Mechanical properties

value range by condition
Hardnessturnedbars, Softened, ground or cold drawn or turned, ground or cold drawn, finallyYield strength Rp0.2≥680 MPaTensile strength Rm850–1000 MPaImpact energy Kv/Ku≥50 JElongation A≥13 %HardnessHBbars +T, <= 150 mmYield strength Rp0.2≥650 MPaTensile strength Rm850–1000 MPaImpact energy Kv/Ku≥35 JElongation A≥13 %HardnessHBbars +T, <= 250 mmYield strength Rp0.2≥755 MPaTensile strength Rm925–1075 MPaImpact energy Kv/Ku≥42 JElongation A≥12 %HardnessHBbars +U, <= 150 mm

Fatigue S-N curve

stress vs. cycles (log)
472473473474474110Cycles
  • 1. Quenched and tempered; T: 20°C; -

Chemical composition

ElementminmaxSimilarRemarks
C0.20.28
Cr33.5
Mn0.450.7
Mo0.450.65
Other0.124 x %P+ %Sn

Mechanical properties

Heat treatment / conditionYield strengthTensile strengthElongationReduction of areaImpact energyHardness
bars, Softened, ground or cold drawn or turned, ground or cold drawn, finallyturned HB
bars +T, <= 150 mm≥680850–1000≥13≥50 KCVHB 248–302 HBW
bars +T, <= 250 mm≥650850–1000≥13≥35 KCVHB 248–302 HBW
bars +U, <= 150 mm≥755925–1075≥12≥42 KCVHB 269–331 HBW
bars +T, >= 6 <= 150 mm≥700；≥680850–1000≥9；≥13≥50 KCVHB 248–302 HBW
bars +U, >= 6 <= 150 mm≥770；≥755925–1075≥9；≥12≥42 KCVHB 269–331 HBW
bars +T, >= 6 <= 250 mm≥650850–1000≥13≥35 KCVHB 248–302 HBW

Fatigue

Test conditions
ItemDetail
Productquenched and tempered
ExperimentT: 20°C
Specimen
Monotonic
PropertyValue
Elastic modulus (GPa)205.0
Yield strength (MPa)781.0
Tensile strength (MPa)976.0
Reduction of area (%)63.0
True fracture strength (MPa)1575.0
True fracture ductility (%)0.99
Strength coefficient (MPa)1153.0
Strain-hardening exponent0.07
Hardness (HB)285.0
Strain life
No.Cyclic yield strength (MPa)Cyclic strain-hardening exponent n′Cyclic strength coefficient K′ (MPa)Fatigue strength coefficient σ′f (MPa)Fatigue strength exponent bFatigue ductility coefficient ε′fFatigue ductility exponent c
16710.100012371130.0-0.061.08-0.66
Stress life
No.Stress (MPa)Cycles
14732E6