● Chemical composition
C: 0. 17 ~ 0.23
Silicon Si: 0. 17 ~ 0.37
Manganese Mn: 0.80 ~ 1. 10
Chromium Cr: 1.00 ~ 1.30
Sulfur S: high-quality steel is not more than 0.030.
High quality steel is not more than 0.020.
Super high quality steel is not more than 0.0 10.
Phosphorus P: high-quality steel is not more than 0.030.
High quality steel is not more than 0.020.
Super high quality steel is not more than 0.020.
Nickel Ni: high-quality steel is not more than 0.30.
High quality steel is not more than 0.30.
Super high quality steel is not more than 0.30.
Copper and Cu (note 1): high-quality steel is not more than 0.30.
High quality steel is not more than 0.25.
Super high quality steel is not more than 0.25.
Titanium: 0.04 ~ 0. 10
Note 1: The copper content of hot-pressing steel is not more than 0.2%.
mechanical character
● Mechanical properties:
Tensile strength σ b (MPa): ≥1080 (110)
Yield strength σ s (MPa): ≥ 835 (85)
Elongation δ5(%):≥ 10
Area shrinkage ψ (%): ≥ 45
Impact work akv (j): ≥ 55
Impact toughness value α kV (j/cm2): ≥ 69 (7)
Hardness: ≤2 17HB
Sample size: the blank size of the sample is 15mm.
●20CrMnTi density: 7.8× 103kg/m3.
Elastic modulus: 207GPa
Poisson's ratio: 0.25
Thermal conductivity:1.26×10-5 (1/℃)
Heat treatment specification
● Heat treatment specification and metallographic structure:
Heat treatment specification: quenching: 880℃ for the first time, 870℃ for the second time, oil cooling; Tempering at 200℃, water cooling and air cooling.
Detailed heat treatment specifications and mechanical properties;
Sample blank size/mm: 15
Heat Treatment | Quenching | Heating Temperature/℃| First Quenching: 880℃
Heat Treatment | Quenching | Heating Temperature/℃| Second Quenching: 870℃
Heat treatment | quenching | coolant: oil
Heat Treatment | Tempering | Heating Temperature /℃: 200℃
Heat treatment | tempering | Coolant: water and air.
Mechanical properties | tensile strength σb/MPa|≥: 1080
Mechanical properties | yield point σs/MPa|≥: 850
Mechanical properties | Elongation δ5(%)|≥: 10
Mechanical properties | area shrinkage ψ(%)|≥: 45
Mechanical properties | impact absorption work AKV/J|≥: 55
HBS hardness in delivery state |≥: 2 17
● Heat treatment specification and metallographic structure:
Heat treatment specification: quenching: 880℃ for the first time, 870℃ for the second time, oil cooling; Tempering at 200℃, water cooling and air cooling;
Metallographic Organization: tempered martensite.
● Delivery status: The goods shall be delivered by heat treatment (normalizing, annealing or high temperature tempering) or non-heat treatment, and the delivery status shall be indicated in the contract.
● Density and elastic modulus of ●20CrMnTi:
Density: 7.8× 103kg/m3 Elastic modulus: 207GPa Poisson's ratio: 0.25 Thermal conductivity:1.26x10-51℃.
●20CrMnTi standardization
20CrMnTi normalizing, 20CrMnTi steel heating at 860℃, rapid cooling to 680℃, isothermal normalizing, and fog cooling and high temperature normalizing after heating at 960℃, and the differences and functions of the two processes are compared.