Calibration of leaving factory: Pre-harden it until it is 980-1080N/mm2(30-34HRC).

Characteristic: This steel belongs to P20 which is coated on 1.1％ nickel; it is even in hardness from surface into the center, good in cutting, excellent in sparking and polishing; it is adapted for gasification, hard chromium plating and titanium plating.

Use: It is adapted for plastic mould of high demand, especially for that is more than 400mm.

Anneal: Heat up to 720-740℃ and preserve for enough time; then reduce to 600℃ with the furnace and cool it in air; the hardness is about 240HB at most.

Stress removing: Heat up to 600℃ and preserve in gas furnace for about 2 hours; then cool it slowly with the furnace.

Quenching: Heat up to 840-860℃and then quench oil after preservation; or heat up to 860-880℃ and then back fire immediately when it is a little more than room temperature; the hardness is about 54HRC.

Backfire: Back fire immediately after quenching; the time can not be less than 2-2.5h; then come out of the furnace for cooling in air.

Specification: round (MM)

25.8 30.8 32.8 40.8 45.8 50.8 55.8 60.8 66.0 71.0 76.0 81.0 86.0 91.0 101.5
106.5 116.5 126.5 141.5 151.5 182.0 202.0 232.0 262.5 282.5 302.5 363.0 403.0

Quadrate (MM)
25323540455060708090105
Flat(MM)
80X20-25-32-35-40-45-50-60-65-70
105X20-25-32-35-40-45-50-60-65-70-80
130X20-25-32-35-40-45-50-60-65-70-80-90-105
155X20-25-32-35-40-45-50-60-65-70-80-90
180X20-25-32-35-40-45-50-60-65-70-80
210X20-25-32-35-40-45-50-60-65-70-80-90-105
230X20-25-32-35-40-45-50-60-65-70-80
260X20-25-32-35-40-45-50-60-65-70-80-90-105
310X20-25-32-35-40-45-50-60-65-70-80-90-105
420X20-25-32-35-40-45-50-60-65-70-80-90-105-115-130-140-155
620X20-25-32-35-40-45-50-60-65-70-80-180-210-230
700X20-25-32-35-40-45-50-60-65-70-80-260-310-360