H13 Tool Steel

Introduction to H13 Tool Steel

1. Overview

H13 tool steel is a hot-work tool steel widely used in applications such as hot forging dies, die-casting molds, and extrusion dies. Known for its excellent high-temperature strength, wear resistance, and thermal fatigue resistance, H13 steel is highly favored in the mold manufacturing industry.

2. Chemical Composition

The chemical composition of H13 steel includes:

Carbon (C): 0.32-0.45%

Silicon (Si): 0.80-1.20%

Manganese (Mn): 0.20-0.50%

Chromium (Cr): 4.75-5.50%

Molybdenum (Mo): 1.10-1.75%

Vanadium (V): 0.80-1.20%

These elements work together to provide H13 steel with exceptional thermal stability and mechanical properties.

3. Physical Properties

Density: 7.8 g/cm³

Thermal Expansion Coefficient: 12.2 x 10⁻⁶/°C (20-100°C)

Thermal Conductivity: 24.3 W/m·K (20°C)

Elastic Modulus: 210 GPa

4. Mechanical Properties

Hardness: After proper heat treatment, H13 steel can achieve a hardness of 50-54 HRC.

Tensile Strength: Approximately 2000 MPa

Yield Strength: Approximately 1600 MPa

Elongation: Approximately 10%

5. Heat Treatment Process

The heat treatment process for H13 steel includes annealing, quenching, and tempering:

Annealing: Heat to 845-900°C, hold, and slowly cool to achieve a hardness of 220-230 HB.

Quenching: Heat to 1000-1050°C, then cool in oil or air to achieve a hardness of 55-57 HRC.

Tempering: Temper at 540-650°C to achieve a hardness of 50-54 HRC.

6. Applications

H13 steel is primarily used in:

Hot Forging Dies: Such as forging hammer dies and press dies.

Die-Casting Molds: For aluminum and magnesium alloy die-casting.

Extrusion Dies: For copper and aluminum alloy extrusion.

Plastic Molds: Suitable for high-temperature plastic molding.

7. Advantages

High-Temperature Strength: Maintains high strength and hardness at elevated temperatures.

Wear Resistance: Excellent wear resistance, extending mold life.

Thermal Fatigue Resistance: Good resistance to thermal fatigue, suitable for cyclic heating and cooling environments.

Machinability: Good machinability and heat treatment performance.

8. Precautions

Heat Treatment Control: Strictly control heat treatment processes to avoid overheating or overcooling.

Surface Treatment: Surface treatments such as nitriding or chrome plating can enhance wear and corrosion resistance.

Usage Environment: Avoid using in excessively high temperatures or corrosive environments to prevent material degradation.

9. Conclusion

H13 tool steel, with its exceptional high-temperature strength, wear resistance, and thermal fatigue resistance, is the material of choice for hot-work molds. Through proper heat treatment and surface treatment, the service life and performance of H13 steel molds can be further enhanced, meeting the demands of various complex and harsh working environments.