45B, alloy structural steel.
Unified digital code: A70452
[] Chemical composition (mass fraction) (%)
C: 0.42 ~ 0.49
Si: 0.17 ~ 0.37
Mn: 0.60 ~ 0.90
B: 0.0005 ~ 0.0035
[] 45B alloy mechanical properties of structural steel
Blank sample size (mm): 25
Heat treatment: the first quenching temperature (℃): 840; coolant: water
Second quenching temperature (℃): -
Tempering heating temperature (℃): 550; coolant: water
Tensile strength (σb / MPa): ≧ 835
Yield point (σs / MPa): ≧ 685
Elongation (δ5 /%): ≧ 12
Reduction of (ψ /%): ≧ 45
Impact absorbed energy (Aku2 / J): ≧ 47
Brinell hardness (HBS100/3000) (annealing or tempering condition): ≦ 217
Key Features] [45 more steel this steel has high hardness, strength, wear resistance and hardenability, quenching in water, the critical diameter of 17 ~ 30mm, the critical quenching in oil diameter of 7 ~ 15mm.
[Application Example] usually used in the quenched state, for the manufacture of steel cross-section larger than 45, higher parts; such as the crank handle tractors and other similar parts. In addition, the manufacture of small size, less demanding parts, can replace 40Cr steel.
