24 July 2021 Mould Steel Bar
3Cr2NiMo Mould Steel Bar
3Cr2NiMo steel is pre-hardened high-grade plastic mould steel, which is an improved 3Cr2Mo steel, which is added with 0.8% -1.2% nickel in 3Cr2Mo steel, which has high hardenability and good polishing Performance, EDM performance and striae processing performance.
3Cr2NiMo steel is an improved 3Cr2Mo steel, is added to the mass fraction of 3Cr2Mo steel 0.8% to 1.2% of nickel, the chemical composition shown in Table 3-7. Consistent with the P20 steel modified 718 steel produced in Sweden.
Chemical composition (mass fraction) (%):
- Cr 1.70 ~ 2.00
- Mo 0.25 ~ 0.40
- Ni 0.85 ~ 1.15
- P ≤ 0.020
- S ≦ 0.015
Phase transition point Ac1725 ℃, Ac3810 ℃, Ms280 ℃. 2 production process
Alkaline open hearth rough vacuum degassing, ladle powder metallurgy hydraulic press forging roughing ultrasonic testing quenching and tempering heat test factory. The steel produced by this process achieves high cleanliness, fine structure and good mirror polishing performance, and the surface roughness can reach Ra0.05 ~ 0.025m.
3Cr2NiMo steel is pre-hardened high-grade plastic mold steel, which is an improved 3Cr2Mo steel, which is added with 0.8% -1.2% nickel in 3Cr2Mo steel, which has high hardenability and good polishing Performance, EDM performance and striae processing performance. Has no pre-hardened hardened, suitable for electric erosion processing and mirror polishing, comprehensive mechanical properties, can be hardened to> 40HRC.
The steel can also be nitriding, boronizing and other chemical heat treatment, the surface hardness after treatment by 370 ~ 420HV increased to 100HV significantly improve mold resistance and corrosion resistance, but also the surface of the mold chrome. Mold can also be repaired after partial damage repaired welding, welding quality is good, can be processed. Used in the pre-hard state, to prevent heat treatment deformation. The steel is now included in our standard GB / T1299-2000 and YB / T 094-1997.
After quenching at 860 ℃ and tempering at 650 ℃, the mechanical properties at room temperature and high temperature are shown in Table 3-8.
3Cr2NiMo die mould steel mechanical properties:
Test temperature / ℃ b / MPa s / MPa (%) (%) k / (J / cm2) HRC
Room temperature 1235
200 1006 882 13.6 56
400 882 811 14.0 67
3Cr2NiMo steel in the hardness value of 32 ~ 36HRC range, with good car, milling, grinding and other processing properties.
3Cr2NiMo steel can also be used flame local heating quenching, heating temperature 800 ~ 825 ℃, in the air or compressed air cooling, the local surface hardness of up to 56 ~ 62HRC, extending mold life. The mold can also be chrome plated, the surface hardness can be increased from 370 ~ 420HV to 1000HV, significantly improve the wear resistance and corrosion resistance of the mold.
3Cr2NiMo steel mold, partial damage can also be repaired repair welding method, the welding quality is good, can be processed.
Application:
3Cr2NiMo steel in the pre-hard state (30 ~ 36HRC) use to prevent heat treatment deformation, suitable for the manufacture of large, complex, precision plastic mold. The steel can also be used nitriding, boronizing chemical heat treatment, the treatment can get higher surface hardness, suitable for the production of high-precision plastic mold.
China GB standard grade 3Cr2NiMo, Sweden UDDEHOLM standard grade IMPAX HI HARD, the United States AISI standard grade P20 MODIFIED, the United States AISI standard grade P20 + Ni, Germany DIN standard grade 1.2738, Sweden ASSAB standard grade 718 (HH)