3Cr2NiMo 3Cr2Mo steel steel is improved, is added to steel in 3Cr2Mo mass fraction of 0.8% to 1.2% of nickel, its chemical composition shown in Table 3-7. Sweden improved P20 steel production line 718 steel.
Chemical composition (mass fraction) (%)
C Mn Si Cr Mo Ni P S
0.28 ~ 0.40 0.60 ~ 1.00 0.20 ~ 0.80 1.40 ~ 2.00 0.30 ~ 0.55 0.80 ~ 1.20 0.020 0.015
The phase transition point Ac1725 ℃, Ac3810 ℃, Ms280 ℃. (2) the production process
Basic open-hearth smelting vacuum degassing, ladle refining hydraulic forging rough powder ultrasonic flaw detection test quenching heat treatment factory. After this process to produce clean steel to achieve a high degree of organized crime, mirror-polished performance, the surface roughness up to Ra0.05 ~ 0.025m.
Features
Quenched by 860 ℃, 650 ℃ tempering at room temperature and high temperature mechanical properties shown in Table 3-8.
Table 3-8 P4410 mechanical properties of steel
     Application
3Cr2NiMo steel pre-hardened state (30 ~ 36HRC) use, to prevent the heat deformation, suitable for manufacturing large, complex, precision plastic mold. The steel also can be used to nitriding, boronizing and other chemical heat treatment, treatment is given to higher surface hardness, suitable for the production of high precision plastic mold.