Ladish D-6a Ultrahigh Strength Steel Tube,Pipe

Ladish D-6a Ultrahigh Strength Steel Tube Product Information -:- For detailed product information, please contact sales. -: Ladish D-6a Ultrahigh Strength Steel Tube Synonyms -:- For detailed product information, please contact sales. -:

Ladish D-6a Ultrahigh Strength Steel Product Information -:- For detailed product information, please contact sales. -: # **Product Datasheet: Ladish D-6a Ultrahigh-Strength Steel** ## **1. Product Overview** **Ladish D-6a** is a proprietary **ultrahigh-strength, high-hardenability tool and die steel** originally developed by Ladish Company for extreme service applications requiring exceptional compressive strength, wear resistance, and toughness at elevated hardness levels. While technically classified as an air-hardening tool steel, D-6a has been adapted for structural applications where conventional ultrahigh-strength steels are inadequate. Its unique combination of high carbon, chromium, and molybdenum content enables it to achieve and maintain very high hardness (up to 60 HRC) while retaining valuable toughness, making it particularly suitable for applications involving high contact stresses, severe abrasion, and demanding thermal-mechanical cycling. ## **2. International Standards & Designations** | System/Authority | Designation | Specification Title / Relationship | | :--- | :--- | :--- | | **Proprietary** | **Ladish D-6a** | Proprietary specification originally by Ladish Co. (now part of ATI) | | **AISI** | **D6 (Modified)** | Loosely based on AISI Type D6 tool steel with modifications | | **UNS** | **T30406** | Similar to standard D6 tool steel UNS | | **AMS** | **None Direct** | Not a standard AMS material; may be procured to proprietary SOW | | **ASTM** | **A681** | Standard Specification for Tool Steels Alloy (Type D6 approximate) | | **Common Names** | D-6a, Ladish D6a, High-Hardenability D6, Super D6 | **Note:** D-6a is a **proprietary grade** with specifications often defined by customer-manufacturer agreements rather than open standards. Chemistry and properties can vary slightly based on manufacturer and application. ## **3. Chemical Composition (% by Weight)** D-6a features a high-carbon, high-chromium, molybdenum-vanadium alloy system designed for deep hardening and secondary hardening response. | Element | Ladish D-6a Typical Range | AISI D6 (for comparison) | Primary Metallurgical Function | | :--- | :--- | :--- | :--- | | **Carbon (C)** | **1.40 - 1.60** | 1.40 - 1.60 | Provides high hardness and wear resistance via carbide formation | | **Manganese (Mn)** | **0.30 - 0.60** | ≤ 0.60 | Austenite stabilizer, aids hardenability | | **Phosphorus (P)** | **≤ 0.025** | ≤ 0.030 | Impurity control | | **Sulfur (S)** | **≤ 0.020** | ≤ 0.030 | Impurity control; may be enhanced for machinability | | **Silicon (Si)** | **0.20 - 0.50** | 0.10 - 0.40 | Deoxidizer, solid solution strengthener | | **Chromium (Cr)** | **11.0 - 13.0** | 11.0 - 13.0 | Primary carbide former, provides corrosion/oxidation resistance and deep hardenability | | **Molybdenum (Mo)** | **0.70 - 1.20** | 0.70 - 1.20 | Enhances hardenability, refines grain, promotes secondary hardening | | **Vanadium (V)** | **0.80 - 1.20** | 0.90 - 1.10 | Strong carbide former, refines grain, improves wear resistance and toughness | | **Cobalt (Co)** | **0.20 - 0.50 (optional)** | -- | Increases hot hardness and tempering resistance | | **Tungsten (W)** | **0.50 - 1.00 (optional)** | -- | Enhances hot hardness and wear resistance | | **Iron (Fe)** | Balance | Balance | Matrix | **Key Microstructural Features:** Contains a high volume fraction of hard, complex (Cr, Fe)₇C₃ and (V, Mo)C carbides in a high-hardness martensitic matrix, providing exceptional abrasion resistance. ## **4. Mechanical & Physical Properties** Properties are highly dependent on heat treatment, particularly tempering temperature. | Property | Typical Range (Hardened & Tempered) | Condition / Notes | | :--- | :--- | :--- | | **Standard Heat Treatment** | **Austenitize:** 980-1025°C (1800-1880°F), Air or Oil Quench
**Temper:** Double temper at 480-540°C (900-1000°F) | Achieves secondary hardening peak | | **Hardness** | **58 - 62 HRC** (As-quenched: 64-66 HRC) | At secondary hardening peak (tempered) | | **Ultimate Tensile Strength** | **~1900 - 2100 MPa (275 - 305 ksi)** | Estimated from hardness, difficult to test directly | | **Compressive Yield Strength** | **~2500 - 3000 MPa (360 - 435 ksi)** | **Key property:** Extremely high | | **Modulus of Elasticity** | **210 - 220 GPa (30.5 - 31.9 × 10⁶ psi)** | | | **Fracture Toughness (K_IC)** | **~20 - 35 MPa√m** | Low compared to structural steels but good for this hardness level | | **Abrasion Resistance** | **Excellent** | Superior to most tool steels at equivalent hardness | | **Density** | **~7.7 - 7.8 g/cm³** | | | **Thermal Conductivity** | **~25 W/m·K @ 20°C** | Relatively low | | **Coefficient of Thermal Expansion** | **~10.5 × 10⁻⁶ /°C (20-100°C)** | | | **Maximum Service Temperature** | **~425 - 480°C (800 - 900°F)** | Before significant softening | ## **5. Key Characteristics & Advantages** * **Unmatched Compressive Strength:** One of the highest compressive yield strengths of any commercial steel, ideal for high-contact-stress applications. * **Exceptional Wear & Abrasion Resistance:** High carbide volume provides outstanding resistance to sliding wear, galling, and abrasion. * **Deep & Uniform Hardenability:** Air-hardening capability minimizes distortion and quench cracking risks in complex shapes. * **Good Dimensional Stability:** Minimal size change during heat treatment compared to oil-hardening steels. * **Secondary Hardening Response:** Hardness can actually increase upon tempering in the 480-540°C range, allowing high hardness to be maintained after stress relief. * **Moderate Corrosion Resistance:** High chromium content provides better oxidation and corrosion resistance than many tool steels. ## **6. Primary Applications** Originally a die steel, D-6a's unique properties have led to its use in extreme structural and wear applications. * **Aerospace Tooling & Dies:** Extrusion dies for high-temperature alloys, forging dies for titanium and nickel superalloys. * **Critical Wear Components:** Bearing races, high-load rollers, and wear plates in severe service. * **Specialty Fasteners & Pins:** For applications requiring extreme shear and compressive strength. * **Oil & Gas Tooling:** Components for deep drilling and downhole tools subjected to extreme abrasion and compression. * **High-Performance Automotive:** Racing transmission components, specialized bearings, and wear-critical parts. * **Industrial Machinery:** Rolls for cold rolling mills, guide rolls, and anvil blocks for high-impact applications. * **Knives & Cutting Tools:** For specialized industrial cutting where extreme wear resistance is needed. * **Military/Aerospace Structural:** Select components in aircraft and vehicles where wear resistance and compressive strength are primary design drivers. ## **7. Processing & Fabrication Guidelines** * **Annealing:** Heat to 870-900°C (1600-1650°F), slow furnace cool to 540°C (1000°F), then air cool. Typical annealed hardness: 200-250 HB. * **Stress Relieving:** After rough machining, heat to 650-675°C (1200-1250°F) and slow cool. * **Preheating:** Essential before austenitizing to prevent thermal shock. Heat uniformly to 750-800°C (1380-1470°F). * **Austenitizing:** 980-1025°C (1800-1880°F) in controlled atmosphere. Soak time: 30-60 minutes per inch of thickness. * **Quenching:** Air cool or oil quench (depending on section size and required properties). Air cooling is preferred to minimize distortion. * **Tempering:** **Immediate tempering is mandatory.** Double or triple temper at 480-540°C (900-1000°F) for 2+ hours each. Cool to room temperature between tempers. * **Machining:** Must be performed in the annealed condition. Use carbide tooling, positive rakes, and adequate cooling. Abrasive machining (grinding) is required after hardening. * **Welding:** **Extremely difficult and not recommended.** If absolutely necessary, requires high preheat (~400-500°C), specialized filler metals, and full re-heat treatment. Cracking risk is very high. ## **8. Limitations & Design Considerations** * **Low Fracture Toughness:** Typical of high-hardness, high-carbide steels. Not suitable for applications with high tensile stress concentrations or impact loading. * **Poor Machinability (Hardened State):** Can only be finished by grinding or EDM after heat treatment. * **Size Limitations:** Very large sections may not harden uniformly through the core. * **High Cost:** Premium material with specialized heat treatment requirements. * **Sensitivity to Decarburization:** Must be processed in protective atmospheres during heat treatment. ## **9. Comparison with Other Ultrahigh-Strength Materials** | Property | **Ladish D-6a** | AISI 4340 (260 ksi) | M50 Tool Steel | Maraging 250 | | :--- | :--- | :--- | :--- | :--- | | **Typical Hardness** | **58-62 HRC** | 52-54 HRC | 62-65 HRC | 50-52 HRC | | **Compressive Strength** | **~2800 MPa** | ~1900 MPa | ~3000 MPa | ~2000 MPa | | **Fracture Toughness** | 20-35 MPa√m | **70-90 MPa√m** | 15-20 MPa√m | **80-100 MPa√m** | | **Wear Resistance** | **Excellent** | Good | **Excellent** | Fair | | **Primary Application** | Wear/Compression | **Structural/Toughness** | Bearing Steels | **Structural/Toughness** | --- **Disclaimer:** This datasheet describes the general characteristics of the **proprietary Ladish D-6a steel**. As a proprietary material, exact specifications are controlled by the manufacturer (now ATI) and are subject to change. **There is no publicly available standard specification (like an AMS or ASTM) for D-6a.** All procurement and design must be based on direct consultation with the material producer and the issuance of a detailed technical purchase specification. The information presented here is based on historical data and typical industry knowledge; actual properties for a specific lot or application may vary. Use in critical applications requires extensive testing and validation. -:- For detailed product information, please contact sales. -: Ladish D-6a Ultrahigh Strength Steel Specification Dimensions Size： Diameter 20-1000 mm Length <6419 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. -: Ladish D-6a Ultrahigh Strength Steel Properties -:- For detailed product information, please contact sales. -:

Applications of Ladish D-6a Ultrahigh Strength Steel Tube -:- For detailed product information, please contact sales. -: Chemical Identifiers Ladish D-6a Ultrahigh Strength Steel Tube -:- For detailed product information, please contact sales. -:

Packing of Ladish D-6a Ultrahigh Strength 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 2890 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