Designation
DIN: | 40 CrMnMoS 8-6
|
AFNOR: | 40 CMD 8.S |
UNI: | - |
AISI: | P20 + S |
Chemical composition:
C | 0.40 |
Si | 0.40 |
Mn | 1.50 |
Cr | 1.90 |
Mo | 0.20 |
S | 0.06 |
Strength:
280 - 325 HB
(≈ 950 - 1100 N/mm²)
Thermal conductivity at 100 °C:
35 W/m K
Character:
alloyed and pre-toughened tool steel, with excellent machinability in the hardened condition because of the Sulphur additive; high dimensional stability
Application:
plates for mould bases and die sets with increased requirements on strength; high-tensile machine parts
Treatment by
not recommended:
Etching, EDM
Polishing:
technical polishing possible; for higher surface requirements we recommend 1.2311 or 1.2738
Nitriding:
increases the steel's wear resistance
Heat treatment:
already pre-toughened; usually no heat treatment required
Nitriding:
Before nitriding, stress-relief annealing at 580 °C is recommended (Meusburger standard).
Hardening:
840 to 860 °C
Cooling:
down to 180 °C/220 °C in oil/hot bath
obtainable hardness: 52 HRC
Tempering:
slow heating to tempering temperature immediately after hardening; then maintain the temperature in the furnace for at least 1 hour per 25 mm part thickness
Technical tip:
- for increased surface quality requirements use material grade 1.2311
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