Gear steel
Steel C, is, man, Cr, Ni, Mo, Ti, 42CrMo: 0.38-0.45, 0.17-0.37, 0.50-0.80, 0.90-1.20, ≤ 0.30, 0.15-0.25. 20CrMnTiH: 0.17-0.23, 0.17-0.37, 0.80-1.10, 1.0-1.30, ≤ 0.30, 0.04-0.10 purpose: 42CrMo: high strength, high hardenability, good toughness, small deformation during quenching, high creep strength and endurance strength at high temperature. It can be used to manufacture forgings with higher strength and larger quenching and tempering section than 35CrMo steel, such as large gear for locomotive traction, transmission gear for supercharger, pressure vessel gear, rear axle, connecting rod and spring clamp with great load. It can also be used for drill pipe joint and fishing tool in oil deep well below 2000m, and can be used for die of bending machine, etc. 20CrMnTiH: it is a good carburizing steel with high hardenability, hard and wear-resistant surface and tough core after carburizing and quenching, high low temperature impact toughness and medium weldability. Good machinability after normalizing. It is used to manufacture important parts with a cross-section less than 30mm, which bear high-speed, medium or heavy load, impact and friction. Such as gear, ring gear, gear shaft crosshead, etc. It is a substitute steel of 18crmnti. Widely used as carburizing parts.
42CrMo heat treatment
Annealing 760 ± 10 ℃, furnace cooling to 400 ℃, air cooling. HB220-230
Normalizing: 860 ± 10 ℃, normalizing and air cooling.
Quenching and tempering at 840 ± 10 ℃ with water or oil, depending on the complexity of product shape, tempering at 680-700 ℃. HB<217
Quenching and tempering at 840 ± 10 ℃ and then tempering at 470 ℃. HRC41-45
Quenching and tempering at 840 ± 10 ℃ and then tempering at 480 ℃. HRC35-45
Quenching and tempering at 850 ℃ and tempering at 510 ℃. HRC38-42
Quenching and tempering at 850 ℃ and tempering at 500 ℃. HRC40-43
Quenching and tempering at 850 ℃ and tempering at 510 ℃. HRC36-42
Quenching and tempering at 850 ℃ and tempering at 560 ℃. HRC32-36
Quenching and tempering at 860 ℃ and tempering at 390 ℃. HRC48-52
Hardness conversion formula
- HS = Bhn / 10 + 12
- Shore hardness (HS) = Rockwell hardness (HRC) + 15
- Bhn = Rockwell hardness (HV)
- HRC = Bhn / 10-3