Key Specifications/Special Features:
Carbon & alloy steel round bars and rods
Revne No.: 873
Materials No.: 1.3255
DIN: S18-1-2-5
EN: HS18-1-1-5
AISI: T4
Chemical composition (in weight %)
C: 0.79%
Si: 0.45% Max.
Mn: 0.40% Max.
Cr: 4.15%
Mo: 0.65%
V: 1.55%
W: 18.00%
Others: 4.75%
Description
This alloy is a high speed, tungsten type tool steel. It is a deep hardening alloy capable of Rockwell C 64 hardness.
Applications
Generally used as cutting tools, broaches and cold extrusion punches, turning, planning and milling cutters for roughing work.
Physical properties (average values) at ambient temperature
Modulus of elasticity [103 x N/mm2]: 217
Density [g/cm3]: 8.70
Thermal conductivity [W/m.K]: 19.0
Electric resistivity [Ohm mm2/m]: 0.65
Specific heat capacity [J/g.K]: 0.46
Soft annealing
Heat to 820-850oC, cool slowly in furnace to 550oC then air. This will produce a maximum Brinell hardness of 265.
Stress relieving
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.
Hardening
Harden from a temperature of 1260-1290oC followed by oil, air quenching or warm bath at 550oC. Hardness after quenching is 63-66 HRC.
Tempering
Tempering temperature: 2x 560-580oC. Hardness after tempering is 64-65 HRC.
Forging
Hot forming temperature: 1150-900oC.
Cold working
In the annealed condition the alloy may be cold worked by conventional methods.
Machinability
Machinability of T4 is only fair. It ranks as 55% that of the W group water hardening simple tool steels.
Corrosion resistance
Although this alloy contains appreciable amount of tungsten it is still not a corrosion resistant alloy. it will rust unless adequately protected.
Welding
The alloy may be welded but has a high tungsten content. Consult the alloy supplier for information relative to welding methods.
| C |
Mn |
Si |
P |
S |
Cr |
Ni |
Mo |
| 0.03 |
0.5 |
0.5 |
0.02 |
0.005 |
11.5~13.5 |
4.5~6.5 |
1.5~3.5 |
Mechanical behavior
State: hardening and tempering state. The supply status is typically 95 or 110 ksi, 0.2% yield strength
Extreme tensile strength: 115 ksi or more (792N / mm2)
0.2% Yield point: 110 ksi or more (758 N / mm2)
Elongation: 15%
V-notch impact strength (-10 ° C): 78 Joules (60ft-lbf)
Hardness: 33%
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