Standard: ASTM A681
Classification:Hot work tool steel
Diameter: 80 to 600 mm ;
Length: 1000 to 9000 mm ;
Tungsten hot work tool steels are of different types, namely, H21 to H26 types. These hot work tool steel have similar characteristics to that of high speed tool steel. The primary alloying elements in tungsten hot work tool steel include tungsten, chromium, carbon, and vanadium. They are resistant to distortion when they are air hardened, and have higher hardening temperature when compared to chromium hot work tool steel. Breakage of the tungsten hot work tool steel can be reduced if they are preheated to operating temperature before use. Thermal shock resistance and toughness of these hot work tool steel can be improved by reducing the carbon content.
H21 hot work tool steel is particularly useful for hot forging and blanking dies and punches for making nuts, bolts and other similar small components. Dies, cores, inserts, pins, etc for the die casting of copper base alloys are also prime applications for this steel. Other uses include forming dies, shear blades, hot extrusion dies, mandrels, punches, die holders, ejector discs and extrusion liners.
C |
Si |
Mn |
P |
S |
Cr |
W |
V |
Ni |
Cu |
0.26-0.36 |
0.15-0.50 |
0.15-0.40 |
0.030 max |
0.030 max |
3.00-3.75 |
8.50-10.00 |
0.30-0.60 |
0.30 max |
0.25 max |
Properties |
Metric |
Hardness, Rockwell C |
40.0 – 55.0 |
Bulk modulus |
140 GPa |
Poisson’s ratio (25°C) |
0.27-0.30 |
Elastic modulus |
190-210 GPa |
1 EAF: Electric Arc Furnace
2 EAF+LF+VD: Refined-smelting and vacuum degassing
3 EAF+ESR: Electro Slag Remelting
4 EAF+PESR: protective atmosphere Electro Slag Remelting
5 VIM+PESR: Vacuum induction melting
1 Hot rolling process
2 Hot Forging: Electro-hydraulic; High-speed-hydraulic; Oil-hydraulic; Precision-forging
1 +A: Annealed (full/soft/spheroidizing)
2 +N: Normalized
3 +NT: Normalized and tempered
4 +QT: Quenched and tempered (water/oil)
1 Black Surface
2 Grounded: Bright but rough ; Not precision
3 Machining for plate: Bright and precision; Little turning scar
4 Peeled/Turned: Bright and precision; Little turning scar
5 Polished: Very Bright and precision size; Not turning scar