Standard: GB / T 1220-1992
● Features and application:
Quenched state, high hardness, good corrosion resistance. For turbine blades.
● Chemical Composition:
Carbon C: 0.16 ~ 0.25
Si Si: ≤ 1.00
Manganese Mn: ≤ 1.00
Sulfur S: ≤ 0.030
Phosphorus P: ≤ 0.035
Chromium Cr: 12.00 ~ 14.00
Ni: to allow containing ≤ 0.60
● Mechanical Properties:
Tensile strength σb (MPa): quenching and tempering, ≥ 635
Conditions yield strength σ0.2 (MPa): quenching and tempering, ≥ 440
Elongation δ5 (%): quenching and tempering, ≥ 20
Reduction of area ψ (%): quenching and tempering, ≥ 50
Impact energy Akv (J): quenching and tempering, ≥ 63
Hardness: Annealed, ≤ 223HB; quenching and tempering, ≥ 192HB
● Heat treatment and microstructure specifications:
Heat treatment specifications: 1) annealing, 800 ~ 900 ℃ slow cooling or rapid cooling of about 750 ℃; 2) quenching, 920 ~ 980 ℃ oil cooling; 3) temper, 600 ~ 750 ℃ fast-cooling.
Microstructure: Organizing for the martensitic type.
● Delivery status: normal to heat treatment delivery, the treatment types specified in the contract; not indicated, according to the heat treatment state of delivery.
