Italy · UNI

C 55

UNI 7845:1978 — UNI 7845

Chemical composition

wt% · log scale
0.010.1110C0.44 – 0.6Mn0.6 – 0.9P0.035S0.035Si0.15 – 0.4
  • min – max range
  • typical value

Mechanical properties

value range by condition
Yield strength Rp0.2≥360 MPaTensile strength Rm660–830 MPaElongation A≥15 %bars, normalized, 16 < d <= 100 mmHardnessHBbarsHardnessHBbars, soft annealed

Chemical composition

ElementminmaxSimilarRemarks
C0.440.6
Mn0.60.9
P0.035
S0.035
Si0.150.4

Mechanical properties

Heat treatment / conditionYield strengthTensile strengthElongationReduction of areaImpact energyHardness
bars, normalized, 16 < d <= 100 mm≥360660–830≥15
barsHB ≤215
bars, soft annealedHB ≤250

Fatigue

Test conditions
ItemDetail
ProductSemi Finished products; Thickness: <= 16 mm; +QT
ExperimentReversed bending; T: 20°C
Specimen
Monotonic
PropertyValue
Yield strength (MPa)550.0
Tensile strength (MPa)800.0 950.0
Elongation (%)12.0
Reduction of area (%)30.0
Stress life
No.Cycles
11E7

Heat treatment

Type1
Heat-treatment curveHardness-Tempering