Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Chemical Composition (%)
C
Si
Mn
B
P
S
Cu
0.37-0.44
0.17-0.37
0.60-0.90
0.0008-0.0035
<=0.030
<=0.030
<=0.30
Mechanical Properties
Tensile Strength
>=785 MPa
Yield Strength
>=635 MPa
Elongation
>=12%
Hardness
<=207 HB
Condition
Quenched and tempered, test sample 25 mm; hardness is for bars delivered annealed or high temperature tempered
More data from GB/T 3077:2015
From the standard
Recommended heat treatment5 settings
Test sample size
25 mm
Quenching temperature
840 deg C
Quenching coolant
water
Tempering temperature
550 deg C
Tempering coolant
water
Allowable deviation: quenching +/-15 deg C, low temperature tempering +/-20 deg C, high temperature tempering +/-50 deg C.
Source: GB/T 3077:2015, Table 3
Mechanical properties, quenched and tempered6 values
Test sample size
25 mm
Tensile strength Rm, min
785 MPa
Lower yield strength ReL, min
635 MPa
Elongation after fracture A, min
12 %
Reduction of area Z, min
45 %
Impact absorbed energy KU2, min
55 J
Minimum values after the recommended heat treatment; if sample is larger than the bar, treat the actual bar.
Source: GB/T 3077:2015, Table 3
Brinell hardness, annealed or high temperature tempered1 value
Brinell hardness HBW, max
207
For steel bars delivered annealed or high temperature tempered.
Source: GB/T 3077:2015, Table 3
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