4Cr13 tool steel standards: GB / T 1220-1992
● Features and application:
4Cr13 die steels after quenching hardness higher than 3Cr13, good corrosion resistance. Use for cutting, nozzle, valve seats and so on. 1Cr17Ni2 features strong resistance to nitric acid and organic acid corrosion. Use as a high hardness and high wear resistance of heat pumps, valves, valve bearings, medical equipment, spring and other parts.
Chemical composition
● Chemical Composition:
Carbon C: 0.36 ~ 0.48
Si Si: ≤ 0.60
Manganese Mn: ≤ 0.80
Sulfur S: ≤ 0.030
Phosphorus P: ≤ 0.035
Chromium Cr: 12.00 ~ 14.00
Ni: to allow containing ≤ 0.60
Mechanical properties
● Mechanical Properties: Hardness: Annealed,, ≤ 201HB, indentation diameter of 3.9 ~ 4.3mm; quenching, ≥ 50HV
● Heat treatment and microstructure specifications:
Heat treatment specifications: 1) annealing, 800 ~ 900 ℃ slow cooling or rapid cooling of about 750 ℃​​; 2) quenching, 1050 ~ 1100 ℃ oil cooling
; 3) temper, 200 ~ 300 ℃ fast-cooling.
Microstructure: Organizing for the martensitic type.
Delivery status
● Delivery status: the status of delivery of steel to annealing. Blacksmithing: oil quenching cold cracking susceptibility of some tool steel, forging heating should not be rapidly heated, preferably 650-750 degrees for a warm-up, forging heating temperature of 1130-1150 degrees, the final forging temperature should be greater than 800 - 850 degrees, take the upper ingot forging temperature. Lower temperature when you get the blank forging
Annealing:
Annealing generally used 780-800 degrees, heat 4-6 hours to ≤ 50 degrees / hour, cooled to 550 degrees baked cooled, isothermal annealing using 700-800 degree heat 2-4 sales, then 670-720 degree heat, to maintain 2-4 hours to ≤ 50 ° / hr cooling rate, cooling to 500 degrees baked cooled, annealed hardness of 241-197HB