D3
D3 Grade Introduction:
Cold-work tool steels which include D2, D3, D4, D5, and D7 steels are high-carbon, high-chromium steels. Apart from D3 steel all group D steels have 1% Mo and are air hardened. Type D3 steel is oil-quenched; though small sections can be gas quenched after austenitization using vacuum. As a result, tools made with type D3 steel tend to be brittle during hardening. Type D2 steel is the most commonly used steel among the group D steels. The D3 steels contain 1.5 to 2.35% of carbon and 12% of chromium.
D3 Grade Application:
- High Strength: AISI D3 Cold Work Steel offers significant strength, making it suitable for demanding applications.
- Good Hardenability: This steel maintains its hardness even when hardened, which is crucial for tool longevity
- Wear Resistance: D3s ability to resist wear makes it ideal for tools that undergo significant friction and abrasion.
- Applications: Commonly used for complex blanking and forming tools, especially for long production runs and for working with hard or abrasive materials.
D3 Equivalent Grades:
| Country |
Standard |
Grades |
| USA |
ASTM A681 |
D3 |
| German |
DIN EN ISO 4957 |
1.2080/X210Cr12 |
| Japan |
JIS G4404 |
SKD1 |
D3 Chemical Composition:
| Element |
C |
Si |
Mn |
P |
S |
Cr |
Ni |
V |
Cu |
W |
| Content (%) |
2.00-2.35 |
0.60 |
0.60 |
0.03 |
0.03 |
11.00-13.50 |
0.30 |
1.00 |
0.02 |
1.00 |
Mechanical Properties:
| Property |
Metric |
Imperial |
| Izod impact unnotched |
28.0 J |
20.7 ft-lb |
| Poisson’s ratio |
0.27-0.30 |
0.27-0.30 |
| Elastic modulus |
190-210 GPa |
27557-30457 ksi |
Physical Properties:
| Property |
Metric |
Imperial |
| Density |
7.7 x 1000 kg/m³ |
0.278 lb/in³ |
| Melting point |
1421°C |
2590°F |
Thermal Properties:
| Property |
Unit |
T (°C) |
Treatment |
| Thermal expansion |
12 x 10⁻⁶/ºC |
20-100 |
– |
Forging Properties:
Pre-heat at 900-950°C then raise temperature to 1050-1100°C. Soak until uniformly heated. D3 tool steel is relatively hard at elevated temperatures. Therefore, initial hammer blows must be light and the temperature must not be allowed to fall below 1020°C until the metal begins to flow. Final forging should not be done below 900°C.
Stress Relieving:
When tools are heavily machined, ground, or otherwise subjected to cold work, the relief of internal strains is advisable before hardening to minimize the possibility of distortion. Stress relieving should be done after rough machining. To stress relief, heat the steel component to 600-650°C. Soak well and cool in the furnace or in the air. The tools may then be finish machined before hardening.