Designation by Standards
Chemical Composition (in weight %)
Hot work, chromium-molybdenum type tool steel that exhibits excellent resistance to softening at elevated tempertaure. This grade is very reistant to thermal fatique cracking (heat cracking), and can be water cooled in service.
It is recommended for difficult hot work tooling applications such as hot punches, forging dies, hot shear blades, extrusion tooling.
Physical properties (avarage values) at ambient temperature
Modulus of elasticity [103 x N/mm2]: 207, 176 (at 500oC), 165 (at 600oC)
Density [g/cm3]: 7.88, 7.69 (at 500oC), 7.65 (at 600oC)
Thermal conductivity [W/m.K]: 30.0, 30.1 (at 500oC), 29.7 (at 600oC)
Electric resistivity [Ohm mm2/m]: 0.37, 0.78 (at 500oC), 0.89 (at 600oC)
Specific heat capacity[J/g.K]: 0.46, 0.55 (at 500oC), 0.59 (at 600oC)
Coefficient of Linear Thermal Expansion 10-6 oC-1
Heat to 780-810oC, cool slowly in furnace. This will produce a maximum Brinell hardness of 229.
Stress relieving to remove machining stresses should be carried out by heating to 600-650oC, holding for one hour at heat, followed by air cooling. This operation is performed to reduce distortion during heat treatment. Hardness after quenching is 44-54 HRC.
Harden from a temperature of 1010-1050oC followed by air, oil quenching or warm bath quenching 450-450oC.
Tempering temperature: 538-621oC, double tempering is required.
Tempering Temperature (oC) vs. Hardness (HRC) vs. Tensile Strength (N/mm2)
Hot forming temperature: 1100-900oC.
90-95% of a 1% carbon steel.
Corrosion resistance of this alloy is better than that of plain carbon steels. However it will rust unless given protective treatment.
All technical information is for reference only.