Welcome to China Baowu Steel Group; E-mail: market@cnbaowusteel.com
Classification of Steel
Introduction to the classification numbers and use of steel
Bearing steel heat treatment
Bearing steel heat treatment should pay attention to several issues
  • Conditions: low speed, light load and no impact Requirements: HT200 HT250 HT300 stress relief annealing
  • Conditions: low speed (< 1m/s), light load, such as lathe slide plate gear, 45 tempering,HB200-250
  • Conditions: low speed, medium load, such as standard series reducer gear requirements :45 40Cr 40MnB (5042MnVB) tempering,HB220-250
  •  Conditions: low speed, heavy load, no impact, such as machine tool spindle box gear requirements :40Cr(42MnVB) quenching medium temperature tempering HRC40-45
  •  Conditions: medium speed, medium load, no fierce impact, such as machine tool spindle box gear requirements :40Cr, 40MnB, 42MnVB tempering or normalizing, induction heating surface hardening, low temperature tempering, aging,HRC50-55

Gears medium speed, medium load or low speed, heavy load

  •  conditions: medium speed, medium load or low speed, heavy load, such as the requirements of the secondary gear in the lathe gearbox :45 high frequency quenching,350-370℃ tempering,HRC40-45(without high frequency equipment, can be used to quickly heat the tooth surface quenching)
  •  Conditions: medium speed, heavy load requirements :40Cr, 40MnB(40MnVB, 42CrMo, 40CrMnMo, 40CrMnMoVBA) quenching, medium temperature tempering fire,HRC45-50.
  • Conditions: high speed, light load or high speed, medium load, impact pinion requirements :15, 20, 20Cr, 20MnVB carburizing, quenching, low temperature tempering, HRC56-62.38CrAl 38CrMoAl nitriding, nitriding depth 0.5mm,HV900
    Conditions: high speed, medium load, no violent impact, such as machine tool spindle wheel. Requirements :40Cr, 40MnB, (40MnVB) high-frequency quenching,HRC50-55.
  •  Conditions: high speed, medium load, impact, complex shape and important gear, such as automobile transmission gear (20CrMnTi hardenability is high, overheating sensitivity is small, carburizing speed is fast, transition layer is uniform, direct quenching deformation after carburizing is small, after normalizing cutting machinability is good, low temperature impact toughness is also good) requirements: 20Cr, 20Mn2B, 20MnVB carburizing, quenching, low temperature tempering or high frequency quenching after carburizing,HRC56-62. 18CrMnTi, 20CrMnTi(forging → normalizing → machining gear → local plating → carburizing, pre-cooling quenching, low temperature tempering → grinding → shot peening) carburizing layer depth 1.2-1.6mm, gear hardness HRC58-60, core hardness HRC25-35. Surface: tempered martensite + residual austenite + carbide. Center: soxtenite + fine pearlite
  • Conditions: high speed, heavy load, impact, modulus < 5 Requirements: 20Cr, 20Mn2B carburizing, quenching, low temperature tempering,HRG56-62.
  • Conditions: high speed, heavy load, or medium load, modulus > 6, requirements: high strength, high wear resistance, such as important spiral bevel gears requirements :18CrMnTi, 20SiMnVB carburizing, quenching, low temperature tempering,HRC56-62
  • Conditions: high speed, heavy load, impact, complex shape of important gears, such as high-speed diesel engines, heavy trucks, aircraft engines and other equipment gears. Requirements :12Cr2Ni4A, 20Cr2Ni4A, 18Cr2Ni4WA, 20CrMnMoVBA(forging → Annealing → rough machining → stress removal → semi-finishing → carburizing → annealing softening → hardening → cold treatment → low temperature tempering → fine grinding) carburizing layer depth 1.2-1.5mm,HRC59-62.
  • Condition: load is not high large gears, such as large gouging gears. Requirements :50Mn2, 50, 65Mn quenching, air cooling,HB≤ 241
  • Conditions: low speed, small load, precise transmission gears. Requirements :35CrMo quenching, low temperature tempering,HRC45-50
  • Condition: precise transmission, large gears with certain wear resistance. Requirements :35CrMo 17 conditioning,HB255-302.
  • Condition: abrasion resistance of metering pump gears required. Requirements :9Cr16Mo3VRE precipitation hardening
  • Condition: Blower gears with high wear resistance is required. Requirements :45 tempering, urea salt bath soft nitriding.
    Condition: 25L oil pump gears with resistance and clearance accuracy is required. Requirements: Powder gold (large production batch).
  •  Condition: tractor rear axle gear (small module), diesel locomotive transmission gear (M6-M8). Requirements :55DTi or 60D(low hardenability medium carbon structural steel) medium frequency quenching, tempering,HRC50-55, or full medium frequency heating quenching. The quality of carburized alloy steel can be obtained, while the process is simplified and the material is cheap.
Chat with us
Chat with us
Questions, doubts, issues? We're here to help you!
None of our operators are available at the moment. Please, try again later.
Our operators are busy. Please try again later
Have you got question? Write to us!
This chat session has ended
Was this conversation useful? Vote this chat session.
Good Bad