Crucible Steel Sheet,Plate,CPM® REX® 66 (HS) High Speed Steel Sheet,Plate

Crucible Steel Sheet/Plate CPM® REX® 66 (HS) High Speed Steel Sheet/Plate Product Information -:- For detailed product information, please contact sales. -: Crucible Steel Sheet/Plate CPM® REX® 66 (HS) High Speed Steel Sheet/Plate Synonyms -:- For detailed product information, please contact sales. -:

Crucible Steel CPM® REX® 66 (HS) High Speed Steel Product Information -:- For detailed product information, please contact sales. -: # **Technical Datasheet: Crucible Steel CPM® REX® 66 (HS) High Speed Steel** --- ## **1. Product Overview** **Crucible CPM® REX® 66 (HS)** is an ultra-premium, **powder metallurgy (PM), cobalt-enhanced tungsten-molybdenum high-speed steel** engineered for applications demanding **exceptional hot hardness coupled with superior wear resistance and toughness**. This proprietary grade represents an advanced evolution within Crucible's REX series, designed to outperform conventional high-cobalt high-speed steels like M42 and M48 in balanced applications where both thermal stability and mechanical reliability are critical. The "66" designation indicates its position within Crucible's performance hierarchy, suggesting optimized characteristics for severe service. Manufactured via Crucible's proprietary CPM process, it features an **ultra-fine, homogeneous microstructure** free from the carbide segregation and inconsistent performance that plague conventional wrought super high-speed steels. This material is specifically formulated for **high-productivity machining of modern superalloys, hardened steels, and abrasive composites** where cutting temperatures are extreme but tool fracture risk must be minimized. --- ## **2. Key International Standards & Designations** | Country/System | Standard Designation | Equivalent/Closest Specification | | :--- | :--- | :--- | | **USA (Crucible)** | **CPM® REX® 66 (HS)** | Proprietary PM Super High-Speed Steel | | **USA (AISI/SAE)** | **- -** | Performance exceeds M42/M48 specifications | | **USA (ASTM)** | **ASTM A600** | Custom PM Grade | | **ISO** | **ISO 4957:2018** | **Custom composition** (Beyond standard) | | **Europe (EN)** | **- -** | Proprietary grade | | **Common Industry Names** | Advanced Cobalt HSS, Balanced Super HSS | - | | **Performance Class** | **Ultra-High-Speed Steel (UHS)** | - | **Note:** CPM REX 66 is a proprietary, performance-optimized alloy without direct AISI or ISO equivalents. It represents Crucible's advanced engineering approach to maximizing the practical performance envelope of cobalt-bearing high-speed steels. --- ## **3. Chemical Composition (Typical %)** The composition is precisely balanced to achieve an optimal synergy between hot hardness, wear resistance, and fracture toughness. | Element | Weight % (Typical) | Metallurgical Function & Rationale | | :--- | :--- | :--- | | **Carbon (C)** | 1.30 - 1.45 | Carefully controlled high carbon content to ensure matrix saturation and support secondary carbide formation without compromising toughness excessively. | | **Tungsten (W)** | 8.00 - 9.00 | Primary contributor to **solid solution strengthening and hot hardness**. Provides excellent thermal stability through tungsten-rich carbides. | | **Molybdenum (Mo)** | 3.50 - 4.50 | Enhances hardenability, refines grain structure, improves toughness, and contributes significantly to secondary hardening response. | | **Chromium (Cr)** | 3.75 - 4.25 | Provides essential hardenability and improves oxidation resistance at elevated temperatures. | | **Vanadium (V)** | 3.00 - 3.50 | **Critical wear element.** Forms a substantial volume of hard vanadium carbides (MC type) for excellent abrasion resistance while maintaining grindability. | | **Cobalt (Co)** | **7.00 - 8.00** | **Performance optimizer.** Enhances matrix **hot hardness and tempering resistance** through solid solution strengthening effects. This level provides significant thermal benefits while preserving better toughness than ultra-high-cobalt grades. | | **Silicon (Si)** | 0.40 - 0.60 | Deoxidizer and matrix strengthener, improves tempering resistance. | | **Manganese (Mn)** | 0.30 - 0.50 | Standard addition for hardenability and deoxidation. | **Advanced Microstructural Features via CPM Process:** - **Optimized Carbide Morphology:** Fine, spherical carbides (2-4 µm) with ideal size distribution for maximum wear resistance without compromising toughness. - **Cobalt Uniformity:** Perfect homogeneity eliminates cobalt segregation bands, ensuring consistent thermal properties throughout the tool. - **Isotropic Mechanical Behavior:** Uniform strength and toughness in all directions, critical for complex cutting tool geometries. - **Enhanced Cleanliness:** Extremely low inclusion content for improved fatigue resistance and edge stability. --- ## **4. Physical & Mechanical Properties** ### **4.1 Standard Heat Treatment** * **Annealing:** Heat to 870-900°C (1600-1650°F), slow cool. Annealed hardness: **~260-290 HB**. * **Preheating:** **Critical.** Triple preheat at 550°C, 800°C, and 1000°C recommended for complex tools. * **Austenitizing:** **1200-1230°C (2190-2245°F).** High temperature required for optimal carbide solutioning. **Precision control (±5°C) mandatory.** Vacuum furnace required. * **Quenching:** **High-pressure gas quench (5+ bar) or salt bath.** * **Tempering:** **Triple tempering is mandatory.** Temper at **550-580°C (1020-1075°F)** for 2+ hours each. **Cryogenic treatment (-80°C/-112°F)** strongly recommended between quench and first temper. * **Expected Hardness:** **67-69 HRC** (can achieve 68-70 HRC with optimized processing). ### **4.2 Mechanical Properties (Hardened & Triple Tempered)** | Property | Value / Rating (Typical) | Performance Context & Advantage | | :--- | :--- | :--- | | **Hardness** | **67 - 69 HRC** | **Extremely high** base hardness, enabling geometrically stable, sharp cutting edges. | | **Hot Hardness (600°C/1112°F)** | **~63-65 HRC** | **Exceptional.** Maintains functional cutting hardness at temperatures where most HSS has softened significantly. | | **Abrasive Wear Resistance** | **Excellent** | Very good due to high hardness and optimized vanadium carbide content. Superior to conventional cobalt HSS grades. | | **Transverse Rupture Strength (TRS)** | **3,000 - 3,600 MPa** | **Very Good for its hardness level.** The balanced composition and PM structure provide better toughness than equivalent hardness conventional cobalt HSS. | | **Impact Toughness** | **Good (for UHS)** | **Key differentiator.** Offers better shock resistance than higher-cobalt UHS grades, making it more suitable for interrupted cuts. | | **Thermal Fatigue Resistance** | **Excellent** | Resists cracking from repeated thermal cycling better than more highly alloyed grades due to balanced thermal expansion characteristics. | | **Grindability** | **Fair to Good** | **Superior to conventional cobalt HSS** due to fine, uniform carbide structure. CBN grinding is most efficient. | ### **4.3 Physical Properties (Approximate)** * Density: ~8.25 g/cm³ * Thermal Conductivity: ~25 W/m·K (Improved over standard HSS) * Coefficient of Thermal Expansion: 11.1 x 10⁻⁶/K * Modulus of Elasticity: 220-225 GPa * Specific Heat: 460 J/kg·K --- ## **5. Typical Product Applications** CPM REX 66 is engineered for **high-performance machining applications** where both thermal and mechanical demands are severe. * **Advanced Cutting Tools:** * **Solid End Mills & Drills:** For **high-speed machining of nickel-based superalloys (Inconel 718, 725, 939), titanium alloys (Ti-6Al-4V, Ti-5553), and hardened steels (50-62 HRC).** * **Gear Hobs & Shaper Cutters:** For precision gear manufacturing in aerospace and power transmission applications. * **Broaches & Reamers:** For finishing critical bores in high-temperature alloy components. * **Turning & Milling Inserts:** For operations where complex chip control geometries are required. * **Specialized Wear Components:** Requiring both high temperature capability and excellent wear resistance in demanding industrial environments. --- ## **6. Processing & Manufacturing Guidelines** * **Machinability (Annealed):** **Very Poor.** The annealed material is hard and abrasive. **EDM is recommended** for complex geometries. If machining, use CBN or premium carbide tooling with conservative parameters. * **Grindability:** **Fair to Good.** **CBN wheels provide optimal performance.** The PM structure allows more efficient grinding than equivalent wrought grades. Diamond wheels can be used for fine finishing. * **EDM Machining:** **Excellent.** The preferred method for producing complex tool shapes. Provides superior accuracy and surface finish. Post-EDM stress relief (180-200°C) is recommended. * **Surface Treatments/Coatings:** An **ideal substrate for advanced PVD coatings (AlTiN, AlCrN, AlTiSiN)**. The high, stable base hardness and excellent surface finish allow coatings to achieve maximum adhesion and performance. --- ## **7. Comparative Performance & Selection Notes** | Criterion | **CPM REX 66** | **CPM REX 76 (M48-type)** | **Conventional M42** | **CPM M4** | | :--- | :--- | :--- | :--- | :--- | | **Cobalt Content** | **7-8%** | **10-11%** | **8%** | **0%** | | **Hot Hardness** | Excellent | **Slightly Higher** | Very Good | Good | | **Wear Resistance** | Excellent | Very Good | Good | **Excellent** | | **Toughness (TRS)** | **Very Good** | Fair | Poor | **Excellent** | | **Grindability** | Good | Fair | Poor | Good | | **Optimal Application** | **Balanced Severe Service** | **Maximum Heat Resistance** | General Cobalt HSS | **High Wear Applications** | **When to Choose CPM REX 66:** 1. Machining **advanced aerospace alloys** where both **heat and abrasion** contribute to tool failure. 2. Applications involve **moderate interrupted cuts or less-than-ideal rigidity** where higher-cobalt grades might fracture. 3. **Maximum productivity with HSS tools** is required, but tool reliability and predictable performance are equally important. 4. It serves as a **premium upgrade from M42/M48** when better toughness and consistency are needed. **The CPM REX 66 Advantage:** This grade represents the **optimal balance point** in the high-cobalt HSS family – providing most of the hot hardness benefits of ultra-high-cobalt steels while maintaining significantly better toughness and manufacturability. --- ## **8. Conclusion** **Crucible CPM® REX® 66 (HS) represents an intelligent engineering achievement in high-speed steel development – a material specifically optimized for the demanding realities of modern high-performance machining.** It successfully addresses the classic compromise between hot hardness and toughness that has limited ultra-high-speed steel applications. This material delivers: - **Near-maximum hot hardness** for high-speed, high-temperature cutting - **Superior toughness** compared to traditional high-cobalt HSS grades - **Excellent wear resistance** through optimized vanadium carbide content - **Predictable, consistent performance** thanks to PM manufacturing For manufacturers pushing productivity boundaries on difficult materials **while maintaining reliable, uninterrupted production**, **CPM REX 66 offers a compelling solution.** It provides the thermal capabilities needed for aggressive cutting parameters while minimizing the risk of catastrophic tool failure that can plague more highly alloyed but brittle alternatives. In the spectrum of cutting tool materials, **CPM REX 66 occupies a valuable position as the most balanced ultra-high-performance HSS**, making it an excellent choice for advanced machining applications where overall tool performance and reliability are more important than any single extreme property. --- -:- For detailed product information, please contact sales. -: Crucible Steel CPM® REX® 66 (HS) High Speed Steel Specification Dimensions Size： Diameter 20-1000 mm Length <5241 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. -: Crucible Steel CPM® REX® 66 (HS) High Speed Steel Properties -:- For detailed product information, please contact sales. -:

Applications of Crucible Steel Sheet,Plate CPM® REX® 66 (HS) High Speed Steel Sheet,Plate -:- For detailed product information, please contact sales. -: Chemical Identifiers Crucible Steel Sheet,Plate CPM® REX® 66 (HS) High Speed Steel Sheet,Plate -:- For detailed product information, please contact sales. -:

Packing of Crucible Steel Sheet/Plate CPM® REX® 66 (HS) High Speed 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 1712 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