Alloy structural steel: 20CrMnTi
Standard: GB / T 3077-1988
● Features and application:
Is case-hardened steel with good performance, high hardenability, quenching after carburizing hard and wear-resistant surface with a tough mind with the Ministry, has a high low temperature impact toughness, weldability medium, after normalizing the cutting of is good. Used to produce cross-section <30mm to withstand high-speed, medium or heavy load, impact and friction of the important parts, such as gears, ring gear, gear shaft cross head.
● Chemical Composition:
Carbon C: 0.17 ~ 0.23
Si Si: 0.17 ~ 0.37
Manganese Mn: 0.80 ~ 1.10
Sulfur S: to allow the residual content of ≤ 0.035
Phosphorus P: allow the residual content ≤ 0.035
Chromium Cr: 1.00 ~ 1.30
Ni: to allow the residual content of ≤ 0.030
Copper Cu: to allow the residual content ≤ 0.030
Ti Ti: 0.04 ~ 0.10
● Mechanical Properties:
Tensile strength σb (MPa): ≥ 1080 (110)
Yield strength σs (MPa): ≥ 835 (85)
Elongation δ5 (%): ≥ 10
Reduction of area ψ (%): ≥ 45
Impact energy Akv (J): ≥ 55
Impact toughness αkv (J/cm2): ≥ 69 (7)
Hardness: ≤ 217HB
Sample size: Sample size is 15mm rough
● Heat treatment and microstructure specifications:
Standard heat treatment: quenching: the first 880 ℃, the second 870 ℃, oil cooling; tempering 200 ℃, water, air-cooled.
● Delivery status: to heat treatment (normalizing, annealing, or tempering) or heat treatment delivery, delivery status should be indicated in the contract.