24 July 2021 Gear Steel Bar
20CrMnMoH Gear Steel Bar
20CrMnMoH steel is a low-alloy gear steel with guaranteed hardenability, good hot workability, good cutting performance after normalizing, good comprehensive mechanical properties and low temperature impact toughness after quenching and tempering, and high bending resistance after carburizing Strength and wear resistance, but poor welding performance, proper preheating before welding, and timely tempering after welding. It is often used to manufacture important carburized parts that require high surface hardness and good wear resistance, such as gears, camshaft connecting rods, pins, etc.
Chemical composition:
- Carbon C: 0.17 ~ 0.23
- Silicon Si: 0.17 ~ 0.37
- Manganese Mn: 0.85 to 1.20
- Sulfur: allow residual content ≤ 0.035
- Phosphorus P: allowable residual content ≤ 0.035
- Chromium Cr: 1.05 ~ 1.40
- Nickel Ni: Allowable residual content ≤0.30
- Copper Cu: allow residual content ≤0.30
- Molybdenum Mo: 0.20-0.30
Mechanical properties:
- Tensile strength σb (MPa): ≥1175(120)
- Yield strength σs (MPa): ≥885(90)
- Elongation δ5 (%): ≥10
- Reduction of area ψ (%): ≥45
- Impact work Akv (J): ≥55
- Impact toughness value αkv (J/cm2): ≥69(7)
- Hardness: ≤217HB Sample size:
- The sample blank size is 15mm
Heat treatment specification and metallographic structure:
Heat treatment specification: quenching at 850℃, oil cooling; tempering at 200℃, water cooling, air cooling. Metallographic structure: tempered martensite.
Delivery status:
delivery in the state of rolling or forging. According to the demand side can also heat treatment (normalizing, annealing or high temperature tempering) state delivery. Delivery status should be indicated in the contract.
Chinese name 20CrMnMoH grade 20CrMnMoH standard GB / T 5216-1985 material name to ensure that the hardenability of structural steel