Material Name: Alloy structural steel
Grade: 30CrMnSiNi2A
● Features and Scope:
After heat treatment to obtain high strength, good ductility and toughness, good fatigue resistance and fracture toughness, low fatigue crack growth rate. High hardenability, machinability and weldability is still good, but the gap and hydrogen embrittlement (including environmental embrittlement) more sensitive. Suitable for high-strength joints and shaft parts and other important force structural components.
● Chemical Composition:
Carbon C: 0.27 ~ 0.34
Si Si: 0.90 ~ 1.20
Mn Mn: 1.00 ~ 1.30
Sulfur S: ≤0.020
Phosphorus P: ≤0.020
Chromium Cr: 0.90 ~ 1.20
Ni Ni: 1.40 ~ 1.80
● Mechanical Properties:
Tensile strength σb (MPa): 1) 1767; 2) 1627
Elongation δ5 (%): 1) 12; 2) 13
Reduction of ψ (%): 50
Impact toughness αku (J / cm2): 1) 79; 2) 90
Sample size: bar
● Heat treatment and microstructure specifications:
Heat treatment specifications: 1) 890 ~ ​​900 ℃ oil quenching, 200 ~ 300 ℃ tempering, air-cooled; 2) 890 ~ ​​900 ℃ heated, quenched into 210 ~ 280 ℃ nitrate bath isothermal 1h, air-cooled, and then at 200 ~ 300 ℃ tempering, air-cooled.
Microstructure: 1) hot-rolled or cold rolled after tempering pearlite; 2) normalizing and tempering is tempered sorbite; 3) After isothermal annealing for
Lamellar pearlite and ferrite; 4) normalized condition of martensite and bainite; 5) in use is tempered horse