United States · AISI

AISI 4140

SAE AMS 6390D:1999 — Steel tubing,mechanical 0.95cr. 0.20mo (0.38. 0.43c) (sae 4140) uns g41400

Chemical composition

wt% · log scale
0.010.1110C0.38 – 0.43Cr0.8 – 1.1Cu0.35Mn0.75 – 1Mo0.15 – 0.25Ni0.25P0.025S0.025Si0.15 – 0.35
  • min – max range
  • typical value

Mechanical properties

value range by condition
HardnessHRsteel tubesHardnessHRsteel tubes, annealed

Fatigue S-N curve

stress vs. cycles (log)
450509569628687110Cycles
  • 2.Heat treated; 293 HB; T: 20°C; -
  • 3.Heat treated; 475 HB; T: 20°C; -
  • 4.303 HB; T: 20°C; -
  • 5.淬火和回火; Drawn at temp; T: 20°C; 方向: L

Chemical composition

ElementminmaxSimilarRemarks
C0.380.43
Cr0.81.1
Cu0.35
Mn0.751
Mo0.150.25
Ni0.25
P0.025
S0.025
Si0.150.35

Mechanical properties

Heat treatment / conditionYield strengthTensile strengthElongationReduction of areaImpact energyHardness
steel tubesHR ≤25 HRC
steel tubes, annealedHR ≤99 Hardened 1038℃

Physical properties

Elastic modulusMean thermal expansionThermal conductivitySpecific heatResistivityDensityPoisson's ratio
200.007.830.32

Typical physical values

DensityElastic modulusPoisson's ratioRemarks
7.72–8.00190.00–210.000.27–0.30典型属性数值，工具钢。此值不来源于标准，它是指示性指标，不能被用于设计用途。
7.85200.00–207.000.27–0.30低碳钢低合金钢的材料性能属性数值，此值不来源于标准，它是指示性指标，不能被用于设计用途。

Fatigue

1.棒材; 25.4 mm; OQ and 540° (1000F); Bending; T: 20°C; Rotating beam; 方向: L

Test conditions
ItemDetail
Productbars; 25.4 mm; OQ and 540° (1000F)
ExperimentBending; T: 20°C
SpecimenRotating beam; Direction: L
Monotonic
PropertyValue
Elastic modulus (GPa)200.0
Yield strength (MPa)986.0
Tensile strength (MPa)1138.0
Elongation (%)15.0
Reduction of area (%)50.0
Hardness (HB)358.0
Stress life
No.SpecimenCycles
1Rotating beam; Direction: LE7

Heat treatment

Type1
Heat-treatment curveCCT modified
Heat-treatment curveHardness-Tempering
Heat-treatment curveCCT
Heat-treatment curveTTT

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