C 0.38-0.42
Si 0.15-0.35
Mn 0.60-0.85
P ≤ 0.03
S ≤ 0.03
Cu ≤ 0.30
Ni ≤ 0.25
Cr 0.90-1.20
MO 0.15-0.30 [1]
Mechanical properties
Tensile strength σb (MPa): ≥ 1080 (110)
Yield strength σs (MPa): ≥ 930 (95)
Elongation δ5 (%): ≥ 12
Reduction of area ψ (%): ≥ 45
Impact energy Akv (J): ≥ 63
Impact toughness αkv (J/cm2): ≥ 78 (8)
Hardness: ≤ 217HB sample size: the size of the sample blank 25mm [2]
sc440 heat treatment
Annealing annealing No.1 "760 ± 10 ℃ annealing, furnace cooling to 400 ℃ air-cooled. HB220-230 normalizing normalize No.4 860 ± 10 ℃ normalizing, baked cooled.
Quenching quenching + tempering No.5 840 ± 10 ℃ quenching water or oil (depending on the product shape complexity),680-700 degree tempered. HB <217
Quenching quenching + tempering No.6 840 ± 10 ℃ quenching oil, 470 degrees and then tempered. HRC41-45
Quenching quenching + tempering No.7 840 ± 10 ℃ quenching oil, 480 degrees and then tempered. HRC35-45
Quenching quenching + tempering No.8 850 ℃ quenching oil, 510 degrees and then tempered. HRC38-42
Quenching quenching + tempering No.9 850 ℃ quenching oil, then tempered to 500 degrees. HRC40-43
Quenching quenching + tempering No.10 850 ℃ quenching oil, and then 510 ℃ tempering. HRC36-42
Quenching quenching + tempering No.11 850 ℃ quenching oil, and then 560 ℃ tempering. HRC32-36
Quenching quenching + tempering No.12 860 ℃ quenching oil, 390 degrees and then tempered. HRC48-52 42CrMo rod pictures
