Bohler-Uddeholm,BÖHLER K294 MICROCLEAN AISI A11 Powder Metal Tool Steel Sheet,Plate

Bohler-Uddeholm BÖHLER K294 MICROCLEAN AISI A11 Powder Metal Tool Steel Sheet/Plate Product Information -:- For detailed product information, please contact sales. -: Bohler-Uddeholm BÖHLER K294 MICROCLEAN AISI A11 Powder Metal Tool Steel Sheet/Plate Synonyms -:- For detailed product information, please contact sales. -:

Bohler-Uddeholm BÖHLER K294 MICROCLEAN AISI A11 Powder Metal Tool Steel Product Information -:- For detailed product information, please contact sales. -: # **Böhler-Uddeholm BÖHLER K294 MICROCLEAN AISI A11 Powder Metallurgy Tool Steel** ## **Product Overview** **BÖHLER K294 MICROCLEAN** is a premium **powder metallurgy (PM) cobalt-rich super high-speed steel** conforming to the AISI A11 classification. Utilizing advanced **MICROCLEAN** powder metallurgy technology, this material achieves an exceptional **homogeneous microstructure with ultra-fine, uniformly distributed carbides**. K294 is engineered to deliver **extreme wear resistance, exceptional red-hardness (hot hardness), and high compressive strength**, positioning it as a top-tier solution for the most demanding machining and cutting applications where conventional high-speed steels reach their performance limits. --- ## **1. Key Characteristics & Advantages** * **Outstanding Red-Hardness:** Exceptional ability to retain hardness at elevated temperatures (up to 600-650°C), surpassing conventional M-series high-speed steels. * **Extreme Wear Resistance:** Superior resistance to abrasive and adhesive wear due to a high volume of very hard, fine carbides (vanadium carbides) uniformly distributed via PM technology. * **High Compressive Strength:** Can withstand extreme mechanical loads without deformation, ideal for heavy-duty machining and forming operations. * **Superior Toughness (for its wear class):** The MICROCLEAN process results in a fine, homogeneous structure that provides better toughness than conventionally produced steels of similar composition and hardness. * **Excellent Grindability:** Despite its high hardness and wear resistance, it offers good grindability compared to other ultra-high-wear PM steels, facilitating tool fabrication and reconditioning. * **Isotropic Properties:** Uniform mechanical behavior in all directions due to the absence of carbide segregation, ensuring predictable performance in complex tool geometries. * **Good Dimensional Stability:** Controlled response to heat treatment with minimal distortion. --- ## **2. Chemical Composition (Weight %)** | Element | Carbon (C) | Tungsten (W) | Molybdenum (Mo) | Chromium (Cr) | Vanadium (V) | Cobalt (Co) | | :--- | :---: | :---: | :---: | :---: | :---: | :---: | | **Content** | **2.30 - 2.60** | **~1.5*** | **~3.8*** | **4.70 - 5.20** | **9.00 - 10.00** | **9.50 - 10.50** | *Note: Exact W and Mo contents are part of the proprietary balance to meet the A11 performance profile. The composition prioritizes very high carbon and vanadium for extreme wear resistance, combined with significant cobalt for red-hardness.* **Alloying Rationale (AISI A11 / MICROCLEAN):** * **Carbon (2.45%) & Vanadium (9.5%):** The core of its wear resistance. Form an extremely high volume of ultra-hard vanadium carbides (VC). The PM process allows this high content without the detrimental large carbides found in conventional casting. * **Cobalt (10.0%):** The key to red-hardness. Cobalt increases the transformation temperature, enhances hot hardness, and improves tempering resistance. * **Chromium (4.95%):** Provides hardenability and contributes to wear and corrosion resistance. * **Tungsten & Molybdenum:** Provide secondary hardening, contribute to hot strength, and balance the carbide system. * **MICROCLEAN Technology:** Ensures an ultra-clean steel with minimal non-metallic inclusions and a perfectly homogeneous carbide distribution, critical for reliability in high-performance tools. --- ## **3. Physical & Mechanical Properties** ### **Physical Properties:** * **Density:** ~8.0 g/cm³ * **Thermal Conductivity:** ~23 W/(m·K) at 20°C * **Modulus of Elasticity:** ~220 GPa * **Coefficient of Thermal Expansion:** ~11.0 x 10⁻⁶/K (20-400°C) ### **Heat Treatment & Mechanical Data:** * **Soft Annealed Hardness:** ~300 HBW * **Austenitizing Temperature:** 1180 - 1220°C (2155 - 2230°F) * **Quenching Medium:** Salt bath, vacuum/pressurized gas (2-5 bar), or oil. * **Tempering:** **Multiple tempering cycles (3x) are mandatory.** Temperature range: 540 - 580°C (1005 - 1075°F). * **Achievable Hardness:** **66 - 70 HRC** * Typical operating range is **67-69 HRC** after triple tempering, offering the optimal balance of wear resistance and toughness for cutting applications. * **Hot Hardness (600°C):** > 60 HRC * **Compressive Strength:** > 4000 MPa (at 68 HRC) * **Transverse Rupture Strength:** ~3000 MPa --- ## **4. Primary Applications** BÖHLER K294 is designed for the most severe machining and cutting applications where heat generation and wear are extreme. * **High-Performance Cutting Tools:** * **End mills, drills, and reamers** for machining superalloys (Inconel, Waspaloy), hardened steels (>50 HRC), and abrasive composites. * **Gear hobs and shaper cutters** for hard finishing of gears. * **Broaches** for high-strength materials. * **Thread rolling dies** for hard or abrasive workpieces. * **Severe Cold Work Applications:** * **Punches and dies** for cold forming and extrusion of difficult materials. * **Powder compaction tools** for hard metal powders. * **Precision blanking dies** for extremely abrasive sheet materials. * **Wear Parts:** Components subjected to severe abrasive wear at elevated temperatures. --- ## **5. Relevant International Standards & Comparable Grades** K294 MICROCLEAN is the proprietary PM embodiment of the AISI A11 standard. | Standard | Grade / Designation | Similarity / Key Difference | | :--- | :--- | :--- | | **AISI / ASTM A600** | **A11 (T15)** | K294 is the premium PM version of this cobalt-rich, high-vanadium super HSS grade. | | **ISO 4957** | **HS12-1-5-5** | The international standard for this type of steel (12%W, 1%Mo, 5%V, 5%Co). K294 offers superior properties via PM. | | **DIN / Werkstoff** | **1.3202 / S12-1-4-5** | Similar European cobalt HSS. The PM structure of K294 provides better toughness and grindability. | | **Other PM HSS** | **Böhler S790** | Another premium Böhler PM super HSS; K294 (A11) has a distinct chemistry focused on very high V and C. | | **PM Cold Work** | **VANADIS 10, CPM 10V** | These are high-vanadium cold work steels. K294 is a *high-speed steel* with significant Co, designed for hot hardness in cutting applications. | | **Conventional HSS** | **M42, M48** | Cobalt HSS grades. K294 (A11 PM) offers significantly higher wear resistance but may have lower toughness. | **Specification Note:** For guaranteed performance, specify **"BÖHLER K294 MICROCLEAN"**. Referring to it as **"PM AISI A11"** or **"PM Super High-Speed Steel"** is also technically accurate. --- ## **6. Processing & Fabrication Guidelines** * **Supply Form:** Round bars, flat stock, and custom preforms. * **Machining:** Must be machined in the soft-annealed condition. Requires rigid setups, sharp carbide or CBN tools, and conservative parameters due to its high work-hardening tendency and abrasiveness. * **Grinding:** **Good grindability for its performance class.** Use aluminum oxide or CBN wheels with ample coolant to avoid thermal damage. The fine PM structure reduces the risk of grinding cracks. * **EDM:** Suitable. A stress-relieving temper (~550°C) is **essential** after EDM to remove the brittle white layer. * **Heat Treatment:** Requires **precise, controlled atmosphere or vacuum heat treatment.** Decarburization must be prevented. 1. **Preheating:** 800-850°C and 1050-1100°C stages are critical. 2. **Austenitizing:** High temperature requires precise control. 3. **Quenching:** Pressurized gas quenching is often preferred for complex tools. 4. **Tempering:** **Triple tempering is non-negotiable.** Cryogenic treatment (-196°C) between the first and second temper is highly recommended to maximize hardness, dimensional stability, and transform retained austenite. * **Surface Treatment:** An excellent substrate for advanced PVD coatings (TiAlN, AlTiN, AlCrN). The coating synergizes with the substrate's hot hardness for extreme performance gains. --- ## **7. Conclusion** **BÖHLER K294 MICROCLEAN** represents the apex of **powder metallurgy super high-speed steel technology**. It embodies the AISI A11 philosophy—maximum wear resistance via high vanadium combined with extreme hot hardness via high cobalt—but realizes it to its full potential through the homogeneity and cleanliness of PM processing. This material is not a general-purpose solution but a **specialist weapon for the most challenging applications**. It is the definitive choice when machining the toughest aerospace alloys, dry or high-speed machining hardened steels, or when tool life with conventional HSS is unacceptably short due to extreme wear or thermal softening. The investment in K294 is justified by unparalleled productivity gains, the ability to machine previously "unmachinable" materials, and drastically reduced tooling costs per part in extreme operating conditions. -:- For detailed product information, please contact sales. -: Bohler-Uddeholm BÖHLER K294 MICROCLEAN AISI A11 Powder Metal Tool Steel Specification Dimensions Size： Diameter 20-1000 mm Length <6895 mm Size:We can customized as required Standard： Per your request or drawing We can customized as required Properties（Theoretical） Chemical Composition -:- For detailed product information, please contact sales. -: Bohler-Uddeholm BÖHLER K294 MICROCLEAN AISI A11 Powder Metal Tool Steel Properties -:- For detailed product information, please contact sales. -:

Applications of Bohler-Uddeholm BÖHLER K294 MICROCLEAN AISI A11 Powder Metal Tool Steel Sheet,Plate -:- For detailed product information, please contact sales. -: Chemical Identifiers Bohler-Uddeholm BÖHLER K294 MICROCLEAN AISI A11 Powder Metal Tool Steel Sheet,Plate -:- For detailed product information, please contact sales. -:

Packing of Bohler-Uddeholm BÖHLER K294 MICROCLEAN AISI A11 Powder Metal Tool Steel Sheet/Plate -:- For detailed product information, please contact sales. -: Standard Packing: -:- For detailed product information, please contact sales. -: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and Steel Sheet/Plate drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 3366 gallon liquid totes Special package is available on request. E FORUs’ is carefully handled to minimize damage during storage and transportation and to preserve the quality of our products in their original condition