SKT4 tool steel is a high-performance, shock-resistant alloy tool steel known for its exceptional toughness and strength. With a chemical composition designed to resist wear and deformation, SKT4 is suitable for heavy-duty applications involving high impact forces and repeated stress. It is often compared to L6 tool steel, with similar characteristics.
Chemical Composition of SKT4 Tool Steel
| Element | Composition (%) |
|---|---|
| Carbon (C) | 0.55 – 0.65 |
| Chromium (Cr) | 0.60 – 1.00 |
| Manganese (Mn) | 0.50 – 0.80 |
| Silicon (Si) | 0.15 – 0.35 |
| Nickel (Ni) | 1.25 – 1.75 |
| Molybdenum (Mo) | 0.40 – 0.60 |
This combination of elements gives SKT4 tool steel its enhanced toughness and resistance to shock, making it suitable for tools that undergo high mechanical stress.
Physical Properties of SKT4 Tool Steel
| Property | Value |
|---|---|
| Density | 7.85 g/cm³ |
| Hardness (after heat treatment) | 54 – 60 HRC |
| Modulus of Elasticity | 200 GPa |
| Thermal Conductivity | 30 W/m·K |
These properties ensure that SKT4 can endure high impacts without significant deformation or cracking.
Heat Treatment Process for SKT4 Tool Steel
| Process | Temperature Range | Purpose | Cooling Method |
|---|---|---|---|
| Annealing | 800°C – 850°C | Softens the steel for machining | Slow furnace cooling |
| Hardening | 850°C – 900°C | Improves hardness and wear resistance | Oil quenching |
| Tempering | 200°C – 400°C | Reduces brittleness while maintaining toughness | Air cooling |
Heat treatment enhances the wear resistance, hardness, and toughness of SKT4 tool steel, making it suitable for heavy-duty applications.
Equivalent Grades of SKT4 Tool Steel
| Standard | Equivalent Grade |
|---|---|
| AISI (USA) | L6 |
| DIN (Germany) | 1.2713 |
| JIS (Japan) | SKT4 |
These equivalent grades are often used interchangeably across different regions, providing similar properties and applications.
Key Properties of SKT4 Tool Steel
-
Shock Resistance
SKT4 is known for its ability to withstand heavy impacts and shock loading, making it ideal for tools that are subjected to repeated striking forces. -
Toughness
This steel offers a high level of toughness, resisting cracking and breaking even under extreme stress. -
Wear Resistance
Although primarily known for its toughness, SKT4 also provides excellent wear resistance, extending the lifespan of tools used in harsh environments. -
Heat Treatable
SKT4 tool steel responds well to heat treatment, allowing for flexibility in optimizing its mechanical properties based on specific application needs.
Applications of SKT4 Tool Steel
-
Hammers and Anvils
SKT4’s toughness and impact resistance make it ideal for manufacturing hammers, anvils, and similar striking tools. -
Punches and Shear Blades
Due to its wear resistance and toughness, SKT4 is commonly used in punches and shear blades that must endure repetitive stress. -
Cutting Tools
SKT4 is used in a variety of cutting tools that require both toughness and hardness to withstand wear and tear. -
Die Inserts
This tool steel is used in die inserts where high impact and repeated use are common, making it ideal for forging and stamping dies.
Advantages of SKT4 Tool Steel
-
Excellent Shock Resistance
Its ability to withstand heavy mechanical stress makes SKT4 ideal for tools that encounter repeated impacts. -
High Toughness
Even in conditions where other tool steels might crack or chip, SKT4 maintains its integrity. -
Versatility in Heat Treatment
SKT4 can be tailored through heat treatment to meet specific hardness or toughness requirements for different applications. -
Wear Resistance
SKT4 offers excellent wear resistance, ensuring a longer service life for tools exposed to abrasive conditions.
Disadvantages of SKT4 Tool Steel
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Moderate Corrosion Resistance
While SKT4 offers good toughness and shock resistance, it is not particularly corrosion-resistant and may require surface treatments or coatings in humid environments. -
Machinability
Due to its high toughness and hardness, SKT4 can be more difficult to machine, particularly in its hardened condition.
Conclusion
SKT4 tool steel is an outstanding material for applications where shock resistance, toughness, and wear resistance are crucial. Its equivalent to L6 tool steel makes it an excellent choice for tools subjected to high impact forces, such as hammers, punches, and die inserts. With proper heat treatment, SKT4 can be tailored to meet specific needs, making it versatile and reliable in demanding industrial applications.