Sep 17 2012
Topics Covered
IntroductionChemical CompositionPhysical PropertiesMechanical PropertiesThermal PropertiesOther Designations
Introduction
Tungsten hot-work steels are of different types, namely, H21 to H26 types. These steels have similar characteristics to that of high-speed steels. The primary alloying elements of tungsten hot-work steels include tungsten, chromium, carbon, and vanadium. They are resistant to distortion when they are air-hardened, and have higher hardening temperature when compared to that of chromium hot-work steels. Breakage of the tungsten hot-work steels can be reduced if they are preheated to operating temperature before use. Thermal shock resistance and toughness of these steels can be improved by reducing the carbon content.
The following datasheet will provide details of H22 tungsten hot-work tool steels.
Chemical Composition
The following table shows the chemical composition of H22 tool steels.
| Element |
Content (%) |
| C |
0.30-0.40 |
| Mn |
0.15-0.40 |
| Si |
0.15-0.40 |
| Cr |
1.75-3.75 |
| Ni |
0.3 |
| W |
10.00-11.75 |
| V |
0.25-0.50 |
| Cu |
0.25 |
| P |
0.03 |
| S |
0.03 |
Physical Properties
The physical properties of H22 tool steels are outlined in the following table.
| Properties |
Conditions |
| T (°C) |
Treatment |
| Density |
8.36 x 1000 kg/m3 |
25 |
- |
Mechanical Properties
The mechanical properties of H22 tool steels are tabulated below.
| Properties |
Conditions |
| T (°C) |
Treatment |
| Poisson's ratio |
0.27-0.30 |
25 |
- |
| Elastic modulus |
27557-30458 ksi |
25 |
- |
Thermal Properties
The following table shows the thermal properties of H22 tool steels.
| Properties |
Conditions |
| T (°C) |
Treatment |
| Thermal expansion |
11 x 10-6/ºC |
20-100 |
- |
Other Designations
Other designations that are equivalent to AISI H22 tungsten hot-work tool steels include:
- ASTM A681
- FED QQ-T-570
- UNS T20822