Crucible Steel Sheet,Plate,REX® 95 Tungsten Type High Speed Steel Sheet,Plate, AISI T8

Crucible Steel Sheet/Plate REX® 95 Tungsten Type High Speed Steel Sheet/Plate, AISI T8 Product Information -:- For detailed product information, please contact sales. -: Crucible Steel Sheet/Plate REX® 95 Tungsten Type High Speed Steel Sheet/Plate, AISI T8 Synonyms -:- For detailed product information, please contact sales. -:

Crucible Steel REX® 95 Tungsten Type High Speed Steel, AISI T8 Product Information -:- For detailed product information, please contact sales. -: # **Product Introduction: Crucible Steel REX® 95 (AISI T8) Tungsten-Type High Speed Steel** Crucible Steel REX® 95 is a premium, ultra-high tungsten and cobalt high-speed steel (HSS) that conforms to the classic AISI T8 specification. It represents one of the most alloy-rich and performance-intensive grades within the traditional tungsten-based (T-series) high-speed steel family. Engineered for the most extreme machining challenges, REX® 95 is designed to deliver **maximum possible hot hardness (red hardness), exceptional wear resistance, and outstanding cutting edge retention under severe thermal and abrasive duress**. The "95" designation often references its tungsten content, which approaches the upper limit for commercially practical T-series steels. This grade is the definitive choice for applications where intense heat generation at the cutting edge is the primary limiting factor. The synergistic combination of very high tungsten and cobalt content creates a matrix with extraordinary resistance to thermal softening, allowing tools to maintain cutting integrity at temperatures that would rapidly degrade lesser steels. REX® 95 is a specialist material reserved for machining the toughest high-temperature alloys, superalloys, and highly abrasive work-hardening materials. --- ## **1. Chemical Composition (Weight %)** The composition of T8 is defined by extreme levels of tungsten and cobalt, coupled with significant carbon and vanadium. | **Element** | **Tungsten (W)** | **Cobalt (Co)** | **Vanadium (V)** | **Chromium (Cr)** | **Carbon (C)** | | :--- | :--- | :--- | :--- | :--- | :--- | | **Content** | **13.50 - 15.00** | **4.50 - 5.50** | **3.80 - 4.40** | **3.80 - 4.50** | **0.75 - 0.85** | | **Role** | **Primary alloy.** Provides the foundation for **exceptional hot hardness and wear resistance** through solid solution strengthening and the formation of massive, stable tungsten carbides. | **Critical performance enhancer.** Dramatically elevates hot hardness by strengthening the ferrite matrix, resisting tempering effects at extreme cutting temperatures. | **Key wear element.** The very high vanadium content forms an enormous volume of extremely hard vanadium carbides (VC), providing **peerless abrasion resistance** among traditional HSS grades. | Ensures deep hardenability and provides oxidation resistance at elevated temperatures. | Provides the carbon necessary for carbide formation and to achieve high matrix hardness. Balanced to support the high alloy content. | *Note: Iron (Fe) constitutes the remainder. Molybdenum (Mo) is typically minimal (<1.0%). The high vanadium content is a distinctive feature that differentiates T8 from other high-tungsten grades like T4 or T5.* --- ## **2. Physical & Mechanical Properties** *Typical properties after optimal and precise heat treatment to a working hardness of 66-68 HRC.* * **Density:** ~8.50 g/cm³ (0.307 lb/in³) – **Very high**, due to the high tungsten content. * **Modulus of Elasticity:** ~215 GPa (31.2 x 10⁶ psi) * **Thermal Conductivity:** Low; the high volume of carbides impedes heat transfer. * **Hot Hardness (Red Hardness):** **Exceptional.** Maintains a hardness above 63 HRC at temperatures exceeding **650°C (1200°F)**, making it one of the most thermally stable commercial HSS grades. * **Hardness (Typical Working Range):** **65 - 69 HRC.** Commonly applied at **66-68 HRC**. * **Abrasion Resistance:** **Outstanding.** The combination of high-volume tungsten carbides and a very high volume of ultra-hard vanadium carbides provides wear resistance that surpasses most other HSS and approaches that of some powder metallurgy tool steels. * **Toughness:** **Very Low.** This is the critical limitation. The extreme alloy content and high hardness result in **very low impact toughness** and high sensitivity to chipping. It is unsuitable for interrupted cuts or any application with shock loading. * **Compressive Strength:** Extremely high, ideal for tools under pure compressive stress. * **Grindability:** **Extremely Difficult.** The combination of hard tungsten carbides and a high volume of even harder vanadium carbides makes grinding exceptionally challenging and slow. **Diamond abrasives are mandatory** for any efficient grinding operation. --- ## **3. Heat Treatment** Heat treatment of REX® 95 is a complex, high-stakes process requiring expert control and specialized equipment. * **Annealing:** Heat to 870-900°C (1600-1650°F), slow cool at ≤15°C/hr to 600°C. Annealed hardness: 280-330 HB. * **Stress Relieving:** 600-650°C (1110-1200°F), hold, then slow cool. * **Preheating:** **Absolutely Mandatory.** Thorough double preheat: First at 540-650°C (1000-1200°F), then at 815-870°C (1500-1600°F). * **Austenitizing:** **1240-1270°C (2265-2320°F).** **Extreme caution required.** This very high temperature is necessary to dissolve the high volume of tungsten and vanadium carbides. Must be performed in a **controlled atmosphere or vacuum furnace** to prevent catastrophic decarburization. A typical target is **1255°C (2290°F)**. * **Quenching:** **Oil quench** is traditional and common for complex tools, though it increases distortion risk. **Air or gas quenching** can be used for simple geometries. Salt bath was a historical method. * **Tempering:** **Mandatory Multiple Tempers.** Temper immediately after quenching. **Minimum of three tempers** (often four), each for 2+ hours, is essential. * **Typical tempering range: 540-565°C (1005-1050°F).** A strong secondary hardening response is critical. * **Sub-Zero Treatment:** **Essential.** Deep cryogenic treatment (-100°C / -148°F or below) between quenching and the first temper is **non-negotiable** to transform the high levels of retained austenite, ensuring maximum hardness, wear resistance, and dimensional stability. --- ## **4. Key Applications** REX® 95 (T8) is reserved for the most severe, specialized, and thermally demanding machining operations. * **Machining High-Temperature Superalloys:** Turning and boring tools for nickel-based and cobalt-based superalloys (Inconel, Waspaloy, René alloys) in aerospace and power generation. * **Precision Machining of Hardened Steels:** Finishing operations on hardened tool and die steels where extreme wear resistance is required. * **Machining Highly Abrasive Materials:** Certain cast irons and metal matrix composites. * **Specialty Cutting Tools for Production:** Where extreme tool life in continuous, high-temperature cutting is the paramount requirement, and the cost of frequent tool changes is prohibitive. * **Forming and Cutting Tools for Abrasive Non-Ferrous Alloys.** --- ## **5. International Standards & Cross-References** Crucible REX® 95 conforms to the AISI T8 specification. * **AISI/SAE:** **T8** * **UNS:** T12008 * **European (EN):** No direct, widely-used equivalent. It is a high-tungsten, high-cobalt, high-vanadium HSS. * **Japanese (JIS):** **SKH4A** or similar high-vanadium, high-cobalt variants of SKH4 are close analogues. * **ISO:** HS15-1-4-5 (approximate classification). * **Common Trade Names:** T8 HSS, High Vanadium T-series Steel. --- ## **6. Advantages & Limitations** **Advantages:** * **Maximum Hot Hardness & Wear Resistance Combo:** Arguably offers the best combined thermal stability and abrasion resistance among traditional T-series HSS. * **Exceptional Cutting Edge Retention:** Under sustained high-temperature cutting conditions. * **High Compressive Strength:** Can withstand very high cutting pressures. **Limitations:** * **Extremely Low Toughness:** Very brittle; highly prone to catastrophic chipping and fracture. * **Extremely Difficult and Costly to Grind:** Diamond grinding is essential, increasing manufacturing and maintenance costs significantly. * **Complex, High-Risk Heat Treatment:** Requires very high-temperature austenitizing with perfect atmosphere control. High risk of decarburization, grain growth, and distortion. * **Very High Cost:** Due to extreme tungsten, cobalt, and vanadium content. * **High Density:** Results in heavier tools. * **Highly Specialized Application:** Its use is only economically and technically justified in a very narrow range of extreme conditions. --- ## **7. Summary** **Crucible Steel REX® 95 (AISI T8) is the ultimate traditional high-speed steel, pushing the boundaries of tungsten, cobalt, and vanadium alloying to their practical limits.** It is a material of last resort for machining applications where thermal and abrasive wear are so severe that they defeat all other HSS grades. Success with T8 demands flawless heat treatment, impeccable tool geometry and setup, and continuous, uninterrupted cutting conditions. For the aerospace and specialized energy sectors machining the most advanced superalloys, T8 represents a historic benchmark in cutting tool material performance—a tool steel that trades almost all its toughness for unparalleled resistance to heat and wear. It is the definitive choice when the cutting edge must survive in an inferno. -:- For detailed product information, please contact sales. -: Crucible Steel REX® 95 Tungsten Type High Speed Steel, AISI T8 Specification Dimensions Size： Diameter 20-1000 mm Length <6989 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 REX® 95 Tungsten Type High Speed Steel, AISI T8 Properties -:- For detailed product information, please contact sales. -:

Applications of Crucible Steel Sheet,Plate REX® 95 Tungsten Type High Speed Steel Sheet,Plate, AISI T8 -:- For detailed product information, please contact sales. -: Chemical Identifiers Crucible Steel Sheet,Plate REX® 95 Tungsten Type High Speed Steel Sheet,Plate, AISI T8 -:- For detailed product information, please contact sales. -:

Packing of Crucible Steel Sheet/Plate REX® 95 Tungsten Type High Speed Steel Sheet/Plate, AISI T8 -:- 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 3460 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