DHA1 Material Detailed Information
DHA1 is a hot work tool steel developed by Daido Steel. It is an improved version of H13 (JIS SKD61 / DIN 1.2344) with enhanced toughness, heat resistance, and wear resistance, making it suitable for die casting, forging, extrusion dies, and plastic molding applications requiring high thermal fatigue resistance.
This material is widely used in applications where tools and dies are exposed to high temperatures, rapid heating and cooling cycles, and high mechanical loads.
Key Features
- Excellent Heat Resistance: Withstands high temperatures up to 600°C, making it suitable for die casting and forging applications.
- Superior Thermal Fatigue Resistance: Reduces cracking and deformation in applications with repeated thermal cycling, such as aluminum and magnesium die casting.
- High Toughness & Impact Resistance: Better resistance to shock loads and mechanical stress than conventional H13.
- Good Wear Resistance: Suitable for high-pressure injection molds and extrusion dies.
- Excellent Hardness Retention: Maintains high hardness at elevated temperatures, ensuring long tool life.
Chemical Composition
| Element | Composition (%) |
| Carbon (C) | 0.37 – 0.42 |
| Silicon (Si) | 0.80 – 1.20 |
| Manganese (Mn) | 0.25 – 0.50 |
| Chromium (Cr) | 4.80 – 5.50 |
| Molybdenum (Mo) | 1.10 – 1.50 |
| Vanadium (V) | 0.30 – 0.70 |
| Nickel (Ni) | ~0.30 |
| Phosphorus (P) | ≤ 0.030 |
| Sulfur (S) | ≤ 0.020 |
Key Features in Composition:
- High Chromium (Cr) & Molybdenum (Mo) Content: Provides excellent heat resistance and thermal fatigue resistance, reducing cracking in high-temperature environments.
- Vanadium (V) Addition: Enhances wear resistance and strength, preventing softening at high temperatures.
- Optimized Carbon (C) Content: Ensures a balance between hardness, strength, and toughness.
Mechanical Properties
| Property | Value |
| Hardness (Annealed) | ≤ 229 HB |
| Hardness (Hardened & Tempered) | 45 – 52 HRC |
| Tensile Strength | ~1,800 MPa |
| Yield Strength | ~1,500 MPa |
| Elongation | ~10% |
| Impact Toughness | High (Better than SKD61/H13) |
| Thermal Fatigue Resistance | Excellent |
- Superior thermal fatigue resistance compared to standard H13 (SKD61)
- High toughness and impact strength
- Good resistance to wear and cracking under cyclic heating and cooling
- Improved resistance to oxidation at high temperatures
DHA1 vs. Other Hot Work Tool Steels
| Property | DHA1 | SKD61 (H13) | 1.2344 | 1.2367 |
| Hardness (HRC) | 45-52 | 45-50 | 45-50 | 46-52 |
| Thermal Fatigue Resistance | Excellent | Good | Good | Very High |
| Wear Resistance | High | Moderate | Moderate | High |
| Toughness | High | High | Moderate | High |
| Heat Resistance | Superior to SKD61 | Moderate | Moderate | High |
| Applications | Die casting, forging, hot stamping, extrusion | General hot work applications | General hot work applications | Extreme heat applications |
Why Choose DHA1?
- Better heat resistance and toughness than SKD61 (H13).
- Higher resistance to cracking and fatigue in cyclic heating/cooling applications.
- Longer tool life in high-pressure aluminum/magnesium die casting.
Applications
DHA1 is widely used in hot work tooling applications that require high heat resistance, toughness, and wear resistance.
Die Casting Dies & Cores
- Aluminum, magnesium, and zinc die casting molds
- Plunger sleeves, shot sleeves, and cores
- Ejector pins and inserts
Forging & Extrusion Dies
- Hot forging dies for steel and non-ferrous metals
- Extrusion dies for aluminum and copper alloys
Plastic Molding Applications
- High-temperature plastic molds
- Blow molding dies for heat-resistant plastics
Glass Molding & Hot Shear Blades
- Glass pressing and forming dies
- Hot cutting tools and blades
Other High-Temperature Tooling Applications
- Hot stamping dies
- Steel tube and pipe extrusion tooling
Heat Treatment Process
Annealing (Softening for Machining, if Required)
- Heat to 820–860°C, then slowly cool in a furnace.
Hardening
- Preheat at 600–700°C, then heat to 1,000–1,050°C, followed by oil or air quenching.
Tempering
- Temper at 550–650°C to achieve a working hardness of 45-52 HRC, balancing strength and toughness.
Surface Treatments (Optional, for Enhanced Performance)
- Nitriding: Improves wear resistance and surface hardness.
Alternative Materials
- SKD61 (JIS) / H13 (AISI) / 1.2344 (DIN): Standard hot work tool steel with good overall performance but lower thermal fatigue resistance than DHA1.
- 1.2367 (DIN): Offers higher heat resistance than H13/DHA1, but is harder to machine.
- DAC (Daido Steel): Another high-performance hot work steel with good toughness and wear resistance, but DHA1 has better heat resistance.
- DH31-EX (Daido Steel): Higher toughness than DHA1, but lower wear resistance.
Conclusion
DHA1 is a high-performance hot work tool steel that offers superior thermal fatigue resistance, high toughness, and excellent wear resistance, making it ideal for die casting, forging, and extrusion dies.
Best Choice for: High-temperature die casting, forging, and hot extrusion applications
Why Choose DHA1? Better heat resistance, higher toughness, and longer tool life than conventional H13 (SKD61)
