m300/4140 steel by heat treatment, hardness uniformity, up to 31-35HRC, never made ??mold deformation, due to the same level other than the chromium content of steel is high (16% chromium) so its good corrosion resistance characteristics. All general chemicals, corrosion resistant, suitable for manufacture of transparent plastic mold, PVC plastic mold, the role of this stainless steel is more easily reached the required height and the mirror-polished finish, the best title for the same quality of steel.
m300/4140 chemical composition:
C: 0.38
Cr: 16.00
Mn: 0.65
Ni: 0.80
Mo: 1.00
Si: 0.40
m300/4140 heat treatment:
Forging: 1050 ℃ to 850 ℃ began forging the furnace melted and slow cooling.
Annealing :800-850 ℃ air or furnace cooling to 600 ℃, the hardness up to 285HB.
Quenching: the 1000-1050 ℃ oil or air cooling.
Tempering :600-700 ℃ or 170-210 ℃. Be tempered immediately after hardening, the time at least two to 2.5 hours.
Welding: welding, but can be avoided.
m300/4140 purposes:
For exposure to chemical corrosion large, transparent plastic, the camera lens and other kinds of plastic mold, the steel is more opaque effect, easy to reach and required highly polished mirror-polished steel of the best titles for the same product is suitable for contact with all chemicals, plastic molds, transparent plastic products, or items of mold erosion.
