20CrMnMo, Standard: GB/T3077-1999

20CrMnMo is a grade of alloy structural steel. Numeric code: A34202.

Usage:

Commonly used in manufacturing larger, critical carburized parts with high hardness, strength, and toughness (all requirements exceeding those of 15CrMnMo), such as crankshafts, camshafts, connecting rods, shafts for gears, gears, and pinshafts; also, it can be used as a substitute for 12Cr2Ni4.

Chemical Composition:

Quality Score (%):

Carbon (C): 0.17~0.23

Silicon (Si): 0.17～0.37

Manganese (Mn): 0.90～1.20

Sulfur: Allowable residual content ≤ 0.035

Phosphorus (P): Allowable residual content ≤ 0.035

Chromium (Cr): 1.10～1.40

Nickel (Ni): Allowable residual content ≤ 0.030

Copper (Cu): Allowable residual content ≤ 0.030

Molybdenum (Mo): 0.20～0.30

Mechanical properties:

Sample blank dimensions

　　15mm

Heat Treatment

Quenching heating temperature (℃): 850; Coolant: Oil

Hardening Heat Temperature (°C): 200; Cooling Agent: Water, Air

【Mechanical Properties】

Tensile Strength (σb/MPa): ≥1180 Yield Strength (σs/MPa): ≥885

Ultimate elongation (δ5/%)：≥10

Section reduction rate (ψ/%): ≥45

Impact Absorption Work (Aku2/J): ≥55

Brinell Hardness (HBS 100/3000) (annealed or high-temperature tempered condition): ≤217

Delivery Condition: Shipped either in heat treated (normalizing, annealing, or high-temperature tempering) or non-heat treated condition, as specified in the contract.

Delivery Status:

The goods shall be delivered either in heat-treated (normalizing, annealing, or high-temperature quenching) condition or in non-heat-treated condition, and the delivery status should be specified in the contract.