Overview
Special Steel D21.2379, commonly referred to as AISI D2, is a high-carbon, high-chromium tool steel renowned for its wear resistance, toughness, and ability to retain a sharp edge. With a complex matrix of carbides within its structure, D21.2379 is designed to handle the toughest industrial applications, from die casting to cutting tools. This comprehensive guide will delve into the specifics of Special Steel D21.2379, covering its types, composition, properties, applications, specifications, suppliers, pros and cons, and much more.
Types, Composition, and Properties of Special Steel D21.2379
To fully understand Special Steel D21.2379, it’s essential to break down its composition and properties. This steel’s unique formulation gives it exceptional characteristics that make it ideal for various demanding applications.
| Type | Composition | Properties |
|---|---|---|
| D21.2379 Standard | C: 1.55%, Cr: 11.5%, Mo: 0.8%, V: 0.9%, Si: 0.3%, Mn: 0.45% | High wear resistance, good toughness, excellent dimensional stability, high compressive strength |
| D21.2379 Modified | C: 1.55%, Cr: 11.5%, Mo: 1.2%, V: 1.0%, Si: 0.4%, Mn: 0.5% | Enhanced toughness, improved machinability, better grindability, increased resistance to chipping and cracking |
| Powder Metallurgy D21.2379 | C: 1.55%, Cr: 11.5%, Mo: 1.0%, V: 1.0%, Si: 0.3%, Mn: 0.4% | Superior wear resistance, excellent toughness, fine carbide distribution, improved hardness |
| High Vanadium D21.2379 | C: 1.55%, Cr: 11.5%, Mo: 0.8%, V: 1.5%, Si: 0.3%, Mn: 0.4% | Extreme wear resistance, higher hardness, enhanced heat resistance, excellent edge retention |
| Low Carbon D21.2379 | C: 1.45%, Cr: 11.5%, Mo: 0.8%, V: 0.9%, Si: 0.3%, Mn: 0.45% | Improved toughness, slightly reduced hardness, easier heat treatment, better shock resistance |
Properties and Characteristics
Special Steel D21.2379 stands out for its remarkable balance of hardness and toughness. Let’s dive into the detailed properties that make this steel a go-to choice for many industrial applications.
| Property | Description |
|---|---|
| Wear Resistance | Exceptional, due to the high volume of chromium carbides in the matrix. Perfect for tools and dies that face abrasive conditions. |
| Toughness | Good toughness despite its high hardness, making it suitable for heavy-duty applications. |
| Dimensional Stability | Excellent, ensuring minimal distortion during heat treatment. |
| Compressive Strength | Very high, allowing it to withstand significant pressure without deforming. |
| Edge Retention | Maintains a sharp edge for longer periods, reducing the frequency of re-sharpening in cutting applications. |
| Corrosion Resistance | Moderate, adequate for environments where mild corrosion is expected, although not as high as stainless steels. |
Applications of Special Steel D21.2379
Special Steel D21.2379’s unique properties make it suitable for a wide range of applications. Here’s a closer look at where this steel shines the most.
| Application | Description |
|---|---|
| Tool and Die Making | Ideal for creating dies and punches due to its high wear resistance and toughness. |
| Cutting Tools | Used in manufacturing cutting tools that require excellent edge retention and hardness. |
| Plastic Molding | Suitable for molds in the plastic industry where high polishability and wear resistance are crucial. |
| Shear Blades | Perfect for shear blades that cut through tough materials thanks to its superior wear resistance. |
| Cold Work Applications | Used extensively in cold work processes like stamping, drawing, and forming. |
| Industrial Knives | Excellent choice for industrial knives used in recycling and metal processing industries. |
| Bearing Components | Employed in making high-wear components like bearings due to its ability to withstand repeated stress and friction. |
| Precision Tools | Ideal for precision tools that require high dimensional stability and minimal distortion. |
| Coining Dies | Used in coining dies where extreme wear resistance and toughness are needed. |
| Powder Compaction Tools | Employed in tools for powder compaction due to its resistance to wear and ability to maintain dimensional accuracy under high stress. |
Specifications, Sizes, Grades, and Standards
Understanding the specifications, sizes, grades, and standards for Special Steel D21.2379 helps in selecting the right material for specific applications.
| Specification | Detail |
|---|---|
| Standard | ASTM A681, DIN 1.2379, JIS SKD11 |
| Sizes | Available in round bars, flat bars, sheets, and custom shapes |
| Grades | Standard D2, Modified D2, PM D2, High Vanadium D2, Low Carbon D2 |
| Heat Treatment | Typically hardened and tempered at 950-1100°C, followed by air or oil quenching |
| Hardness | Achievable hardness up to 60-62 HRC |
| Tolerances | Can be precision ground to tight tolerances for specific applications |
| Surface Finish | Available in various finishes including annealed, polished, and machined |
Suppliers and Pricing Details
Selecting the right supplier for Special Steel D21.2379 can impact the quality and cost-effectiveness of your project. Here’s a look at some leading suppliers and pricing details.
| Supplier | Location | Pricing | Additional Services |
|---|---|---|---|
| Bohler-Uddeholm | Global | $5-8 per kg | Heat treatment, precision cutting, custom sizes |
| Carpenter Technology | USA | $6-9 per kg | Technical support, machining services |
| Hitachi Metals | Japan | $7-10 per kg | Custom alloy compositions, heat treatment |
| Sandvik | Sweden | $6-8 per kg | Application engineering, technical consultancy |
| Erasteel | France | $5-7 per kg | Custom powder metallurgy, heat treatment |
| Finkl Steel | USA | $6-9 per kg | Precision machining, technical support |
| Rovalma | Spain | $7-10 per kg | Custom solutions, rapid delivery |
| Daido Steel | Japan | $6-9 per kg | Extensive technical resources, custom alloys |
| Schmolz + Bickenbach | Germany | $6-8 per kg | Full-service steel solutions, global delivery |
| Assab Pacific | Singapore | $5-7 per kg | Regional support, specialized steel grades |
Pros and Cons: Advantages and Limitations of Special Steel D21.2379
When choosing Special Steel D21.2379, it’s essential to weigh its pros and cons to determine its suitability for your needs.
| Advantages | Disadvantages |
|---|---|
| High Wear Resistance | Moderate corrosion resistance |
| Excellent Toughness | Difficult to machine in hardened state |
| Good Dimensional Stability | Expensive compared to some other tool steels |
| High Compressive Strength | Requires precise heat treatment to achieve optimal properties |
| Superior Edge Retention | Limited availability in some regions |
| Versatile Applications | Can be brittle if not properly treated |
| Suitable for High-Stress Applications | Higher initial cost can be a barrier for some small-scale applications |
Comparing Special Steel D21.2379 to Other Tool Steels
Understanding how D21.2379 compares to other tool steels can help in making informed decisions.
| Feature | Special Steel D21.2379 | Other Tool Steels (e.g., O1, A2, M2) |
|---|---|---|
| Wear Resistance | Higher due to high chromium carbide content | Generally lower, though some like M2 also offer high wear resistance |
| Toughness | Good balance of toughness and hardness | Varies significantly; O1 has good toughness, while A2 and M2 are slightly more brittle |
| Heat Resistance | Moderate, adequate for most cold work applications | M2 offers superior heat resistance, while O1 and A2 are less heat resistant |
| Machinability | Lower, especially in hardened state | Generally better, especially for O1 and A2 |
| Corrosion Resistance | Moderate, better than carbon steels but worse than stainless steels | Varies, but generally lower except for stainless tool steels |
| Cost | Higher initial cost | Lower cost for O1 and A2, M2 |
FAQ
What is Special Steel D21.2379 best used for?
Special Steel D21.2379 is best used for applications requiring high wear resistance and toughness, such as tool and die making, cutting tools, plastic molds, shear blades, and industrial knives.
How does Special Steel D21.2379 compare to other tool steels?
D21.2379 offers superior wear resistance and toughness compared to many other tool steels. However, it can be more challenging to machine and is typically more expensive.
What are the heat treatment requirements for D21.2379?
Special Steel D21.2379 is typically hardened and tempered at temperatures between 950-1100°C, followed by air or oil quenching to achieve desired hardness and toughness.
Is Special Steel D21.2379 resistant to corrosion?
While D21.2379 offers moderate corrosion resistance, it is not as resistant as stainless steels. It’s suitable for environments where mild corrosion is expected.
What are the typical applications of Special Steel D21.2379?
Typical applications include tool and die making, cutting tools, plastic molding, shear blades, cold work applications, industrial knives, bearing components, precision tools, coining dies, and powder compaction tools.
Can Special Steel D21.2379 be customized?
Yes, many suppliers offer customization options for D21.2379, including modified compositions, precision cutting, and specific heat treatment processes to meet unique application requirements.
Who are the leading suppliers of Special Steel D21.2379?
Leading suppliers include Bohler-Uddeholm, Carpenter Technology, Hitachi Metals, Sandvik, Erasteel, Finkl Steel, Rovalma, Daido Steel, Schmolz + Bickenbach, and Assab Pacific.
What are the main advantages of using Special Steel D21.2379?
The main advantages include high wear resistance, excellent toughness, good dimensional stability, high compressive strength, and superior edge retention.
What are the limitations of Special Steel D21.2379?
Limitations include moderate corrosion resistance, difficulty in machining when hardened, higher cost, and the need for precise heat treatment to achieve optimal properties.
How does the cost of Special Steel D21.2379 compare to other steels?
D21.2379 is generally more expensive than many other tool steels like O1 and A2 but is comparable or slightly higher than high-performance steels like M2.
Conclusion
Special Steel D21.2379, with its high-carbon, high-chromium composition, stands out for its exceptional wear resistance, toughness, and edge retention. Its unique properties make it a preferred choice in demanding industrial applications, from tool and die making to precision cutting tools. While it may come with a higher initial cost and some machining challenges, the performance benefits often outweigh these drawbacks. Understanding its composition, properties, applications, and comparing it with other tool steels helps in making informed decisions for your specific needs. With the right supplier and proper handling, D21.2379 can significantly enhance the durability and efficiency of your tools and components.
