Standard: GB / T 1220-1992
Adding features 0Cr17Ni7Al precipitation hardening steel aluminum species, as a spring, hot laps and scoring device components.

Chemical composition
Carbon C: ≤ 0.09
     Si Si: ≤ 1.00
  Manganese Mn: ≤ 1.00
  Sulfur S: ≤ 0.030
  Phosphorus P: ≤ 0.035
  Chromium Cr: 16.00 ~ 18.00
  Ni-Ni: 6.50 ~ 7.75
  Copper Cu: ≤ 0.50
  Aluminum Al: 0.75 ~ 1.50

Mechanical properties
Tensile strength σb (MPa): solid solution, ≤ 1030; 565 ℃ aging, ≥ 1140; 510 ℃ at
Efficiency, ≥ 1230
  Conditions yield strength σ0.2 (MPa): solid solution, ≤ 380; 565 ℃ aging, ≥ 960; 510 ℃ aging, ≥ 1030
  Elongation δ5 (%): solid solution, ≥ 20; 565 ℃ aging, ≥ 5; 510 ℃ aging, ≥ 4 Reduction of ψ (%): 565 ℃ aging, ≥ 25; 510 ℃ aging, ≥ 10
  Hardness: solid solution, ≤ 229HB; 565 ℃ aging, ≥ 363HB; 510 ℃ aging, ≥ 388HB

Heat treatment
1) solid solution, 1000 ~ 1100 ℃ fast-cooling;
2) 565 ℃ aging, after solution treatment, 760 ± 15 ℃ maintained 90min, in 1h cooled to below 15 ℃, keep 30min, then heated to 565 ± 10 ℃ to maintain 90min, air-cooled;
  3) 510 ℃ aging, after solution treatment, 955 ± 10 ℃ to maintain 10min, cooled to room temperature in less than 24h cooled to -73 ± 6 ℃, keeping 8h, and then heated to 510 ± 10 ℃ to maintain 60min, air-cooled.

Microstructure
Organizing for the precipitation hardening.
Delivery status
Generally heat treatment delivery, the treatment types specified in the contract; not indicated, according to the heat treatment state of delivery.