Bohler-Uddeholm,BÖHLER S390 MICROCLEAN® High Speed Steel Tube,Pipe

Bohler-Uddeholm BÖHLER S390 MICROCLEAN® High Speed Steel Tube Product Information -:- For detailed product information, please contact sales. -: Bohler-Uddeholm BÖHLER S390 MICROCLEAN® High Speed Steel Tube Synonyms -:- For detailed product information, please contact sales. -:

Bohler-Uddeholm BÖHLER S390 MICROCLEAN® High Speed Steel Product Information -:- For detailed product information, please contact sales. -: # **Böhler-Uddeholm BÖHLER S390 MICROCLEAN® High Speed Steel** ## **Product Overview** **BÖHLER S390 MICROCLEAN®** is a premium **high-cobalt, high-vanadium powder metallurgy (PM) super high-speed steel** manufactured using Böhler-Uddeholm's proprietary **MICROCLEAN®** technology. This advanced PM process creates an ultra-homogeneous microstructure with perfectly dispersed, fine carbides, eliminating the segregation and large carbide clusters inherent in conventional metallurgy. S390 is engineered to deliver **exceptional wear resistance, outstanding red hardness (hot hardness), and superior performance stability**, positioning it at the top tier of high-speed steels for machining the most demanding materials under extreme conditions. --- ## **1. Key Characteristics & Advantages** * **Extreme Wear Resistance:** Exceptional resistance to abrasive wear due to a high volume of very hard, finely distributed vanadium carbides (VC), significantly outperforming conventional high-speed steels like M42 and M48. * **Outstanding Red Hardness:** High cobalt content provides excellent retention of hardness and cutting edge integrity at temperatures exceeding 600°C (1110°F), enabling high-speed and dry machining operations. * **Superior Microstructural Homogeneity:** The MICROCLEAN® PM process ensures a perfectly isotropic structure with uniform carbide distribution, providing consistent performance in all directions and predictable heat treatment response. * **High Toughness for its Wear Class:** The homogeneous PM microstructure delivers better toughness and fracture resistance than conventionally produced steels of similar composition and hardness. * **Good Grindability (for its performance level):** While challenging, it offers better grindability than conventional steels with comparable vanadium content, thanks to the fine, uniform carbide distribution. * **Excellent Dimensional Stability:** Minimal and predictable distortion during heat treatment due to the isotropic properties. * **Superior Fatigue Resistance:** Enhanced resistance to thermal and mechanical fatigue compared to conventional high-speed steels. --- ## **2. Typical Chemical Composition (Weight %)** | Element | Carbon (C) | Tungsten (W) | Molybdenum (Mo) | Chromium (Cr) | Vanadium (V) | Cobalt (Co) | | :--- | :---: | :---: | :---: | :---: | :---: | :---: | | **Content** | **1.60 - 1.70** | **2.00 - 3.00** | **4.80 - 5.50** | **4.50 - 5.20** | **4.50 - 5.20** | **7.80 - 8.50** | **Alloying Rationale & PM Advantage:** * **High Vanadium (4.85%):** Primary source of extreme wear resistance through formation of very hard vanadium carbides (VC). In conventional steel, this level would cause severe grindability issues and carbide segregation. * **High Cobalt (8.15%):** Dramatically enhances red hardness by raising the transformation temperature and slowing the coarsening of other carbides at elevated temperatures. * **Balanced Tungsten & Molybdenum:** Provide the classic high-speed steel matrix for hot hardness and secondary hardening. * **High Carbon (1.65%):** Necessary to balance the high vanadium content for optimal carbide formation. * **MICROCLEAN® Technology:** This PM process is essential for this composition. It ensures: * Vanadium carbides are fine (<2-3 μm) and uniformly distributed * No carbide networks or segregation bands * Ultra-low oxygen content (<30 ppm) * Complete alloy homogeneity throughout the material --- ## **3. Physical & Mechanical Properties** ### **Physical Properties:** * **Density:** ~8.05 g/cm³ * **Thermal Conductivity:** ~23 W/(m·K) at 20°C * **Modulus of Elasticity:** ~225 GPa * **Coefficient of Thermal Expansion:** ~10.8 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 (3-6 bar), or oil. * **Tempering:** **Triple tempering is mandatory.** Temperature range: 540 - 580°C (1005 - 1075°F). * **Achievable Hardness:** **67 - 70 HRC** * Typical operating hardness: **68-69 HRC** after triple tempering at 550-560°C. * **Hot Hardness (600°C):** **~62-64 HRC** (Exceptional - approximately 10 HRC points higher than M2 at this temperature) * **Transverse Rupture Strength:** ~3000 - 3300 MPa * **Impact Toughness:** Good for its hardness and wear resistance level; typically better than conventional T15 (A11) at equivalent hardness. * **Grindability:** Fair to good for its performance class; approximately 30-40% better than conventional steel with similar vanadium content. --- ## **4. Primary Applications** S390 MICROCLEAN® is designed for the most demanding machining applications where both extreme wear resistance and high-temperature performance are required. * **Ultra-High-Performance Cutting Tools:** * **End mills, drills, and reamers** for machining hardened steels (>55 HRC), high-temperature superalloys (Inconel 718, Waspaloy, Rene alloys), and abrasive composites. * **Gear hobs and shaper cutters** for hard finishing of high-strength gears. * **Broaches** for difficult-to-machine aerospace materials. * **Thread mills and form tools** for hardened materials. * **High-Speed and Dry Machining:** Tools designed to operate at extreme surface speeds or without coolant where thermal loads are maximized. * **Severe Cold Work Applications:** * **Punches and dies** for cold forming of highly abrasive or work-hardening materials. * **Precision blanking tools** for extremely abrasive sheet materials. * **Wear Parts for Extreme Conditions:** Components subjected to severe abrasive wear at elevated temperatures. --- ## **5. Relevant International Standards & Comparable Grades** S390 MICROCLEAN® is a proprietary PM super high-speed steel with performance characteristics exceeding standard classifications. | Standard | Grade / Designation | Similarity / Key Difference | | :--- | :--- | :--- | | **Proprietary (Böhler)** | **S390 MICROCLEAN®** | Reference ultra-high-performance PM super HSS. | | **AISI / ASTM** | **Beyond M48 / T15 (A11)** | Higher combined V+Co content than standard M48; PM structure provides better properties than conventional T15. | | **ISO 4957** | **HS3-3-4-10** | Approximate classification (3%W, 3%Mo, 4%V, 10%Co). | | **DIN / Werkstoff** | **~1.3249** | Similar cobalt HSS classification, but S390 has higher V. | | **Other PM Super HSS** | **S790 MICROCLEAN®** | Different chemistry within Böhler's ultra-high-performance PM HSS family. | | **Conventional Super HSS** | **T15 (A11)** | Similar high-vanadium concept, but S390 offers superior toughness and grindability via PM technology. | | **PM Cold Work Steel** | **VANADIS 10** | High wear resistance but different metallurgy; S390 is a true high-speed steel with superior hot hardness. | **Performance Positioning:** S390 represents the pinnacle of Böhler-Uddeholm's PM high-speed steel technology, designed for applications where standard super HSS grades reach their performance limits. --- ## **6. Processing & Fabrication Guidelines** * **Supply Form:** Round bars, square bars, precision ground flats, and near-net-shape tool blanks. * **Machining:** **Must be machined in soft-annealed condition.** Requires rigid setups, sharp carbide or CBN tools, and conservative parameters due to high work-hardening tendency and abrasiveness. * **Grinding:** **Challenging but manageable with proper technique.** Use softer-grade aluminum oxide or CBN wheels with ample coolant and frequent dressing. The PM structure provides more consistent grinding than conventional steel but requires attention to avoid thermal damage. * **EDM:** Suitable but requires care. A stress-relieving temper (550°C) after EDM is essential to mitigate the brittle white layer. * **Heat Treatment:** Requires precise, controlled atmosphere or vacuum treatment. 1. **Preheating:** 800-850°C and 1050-1100°C stages are critical. 2. **Austenitizing:** Precise temperature control within narrow range is essential. 3. **Quenching:** High-pressure gas quenching (4-6 bar) is preferred for complex tools to minimize distortion and stress. 4. **Tempering:** **Triple tempering is non-negotiable.** Immediate tempering after quenching is required. Cryogenic treatment (-196°C) between the first and second temper is highly recommended to maximize hardness and dimensional stability. * **Surface Treatment:** An excellent substrate for advanced PVD coatings (AlTiN, AlCrN, DLC). The combination creates tools capable of machining the most challenging materials. --- ## **7. Economic & Technical Justification** ### **Application Scenarios for Selection:** 1. **When machining superalloys** where tool life with M42/M48 is unacceptably short 2. **High-speed dry machining** of hardened steels where thermal stability is critical 3. **Aerospace component manufacturing** where tool reliability and consistency are paramount 4. **Prototype and small-batch machining** of difficult materials where tool changes must be minimized 5. **Applications where both extreme wear and high temperatures** are encountered simultaneously ### **Cost-Benefit Analysis:** * **Typical Tool Life Improvement:** 3-5x over M42 in superalloy machining * **Higher Cutting Speeds:** 20-40% increase possible over conventional super HSS * **Reduced Downtime:** Fewer tool changes and more predictable tool life * **Improved Surface Finish:** Consistent tool performance leads to better part quality --- ## **8. Conclusion** **BÖHLER S390 MICROCLEAN®** represents the **absolute forefront of high-speed steel technology**, combining extreme alloy content with advanced powder metallurgy manufacturing to create a material capable of machining what was previously considered "unmachinable." It breaks the traditional barriers of high-vanadium steels by delivering both exceptional wear resistance and workable grindability through its homogeneous microstructure. For manufacturers pushing the boundaries of machining technology - whether in aerospace, medical, energy, or advanced manufacturing sectors - S390 provides a critical competitive advantage. While representing a significant investment in both material and processing, its performance in the most demanding applications justifies the cost through dramatically extended tool life, increased productivity, and the ability to successfully machine advanced materials that define modern manufacturing challenges. This material is not merely an incremental improvement but a transformative technology for tooling that operates at the extreme edges of performance, making it the definitive choice when failure is not an option and performance cannot be compromised. -:- For detailed product information, please contact sales. -: Bohler-Uddeholm BÖHLER S390 MICROCLEAN® High Speed Steel Specification Dimensions Size： Diameter 20-1000 mm Length <6906 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 S390 MICROCLEAN® High Speed Steel Properties -:- For detailed product information, please contact sales. -:

Applications of Bohler-Uddeholm BÖHLER S390 MICROCLEAN® High Speed Steel Tube -:- For detailed product information, please contact sales. -: Chemical Identifiers Bohler-Uddeholm BÖHLER S390 MICROCLEAN® High Speed Steel Tube -:- For detailed product information, please contact sales. -:

Packing of Bohler-Uddeholm BÖHLER S390 MICROCLEAN® High Speed Steel Tube -:- 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 Tube 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 3377 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