Latrobe,Lescalloy® 35NCD16 VAC-ARC High Strength Alloy Steel Foil/Strip

Latrobe Lescalloy® 35NCD16 VAC-ARC High Strength Alloy Steel Foil Product Information -:- For detailed product information, please contact sales. -: Latrobe Lescalloy® 35NCD16 VAC-ARC High Strength Alloy Steel Foil Synonyms -:- For detailed product information, please contact sales. -:

Latrobe Lescalloy® 35NCD16 VAC-ARC High Strength Alloy Steel Product Information -:- For detailed product information, please contact sales. -: # **Product Datasheet: Latrobe Lescalloy® 35NCD16 VAC-ARC High Strength Alloy Steel** ## **Executive Summary** Latrobe Lescalloy® **35NCD16 VAC-ARC** is a premium **nickel-chromium-molybdenum (Ni-Cr-Mo) high-strength, high-toughness alloy steel** refined through **Vacuum Arc Remelting (VAR)**. Characterized by its **exceptional hardenability, superior impact resistance, and excellent strength-ductility balance**, this steel is engineered for critical, heavy-section components subjected to extreme dynamic loading and stress. The **VAC-ARC process** ensures optimal purity and homogeneity, making it the material of choice for the most demanding defense, aerospace, and energy applications where reliability under fatigue and shock loading is paramount. --- ## **Material Technology & Processing** **Metallurgical Design Philosophy:** 35NCD16 is a classic **3.5% Nickel - 1.5% Chromium - 0.25% Molybdenum** alloy designed to deliver deep hardening and remarkable toughness, even at sub-zero temperatures. The **VAR secondary refining** provides decisive advantages for critical components: - **Enhanced Inclusion Control:** Significantly reduces oxide and sulfide inclusions, drastically improving transverse impact strength and fatigue endurance. - **Reduced Segregation:** Creates a uniform distribution of alloying elements, ensuring consistent mechanical properties throughout large cross-sections. - **Improved Hydrogen Removal:** Minimizes hydrogen content, reducing the risk of hydrogen embrittlement and flaking. - **Superior Microstructural Uniformity:** Results in predictable and isotropic mechanical behavior. **Heat Treatment Response:** This alloy exhibits excellent response to conventional quenching and tempering, achieving a wide range of strength-toughness combinations. Its deep hardenability allows for through-hardening of very large sections. --- ## **Chemical Composition (Typical Weight %)** *Balanced for optimal hardenability and toughness; VAC-ARC ensures tight control.* | Element | Content Range (%) | Metallurgical Function | |---------|------------------|------------------------| | **Carbon (C)** | 0.32 - 0.38 | Provides base strength through martensite formation. | | **Nickel (Ni)** | 3.25 - 3.75 | Primary toughening agent; lowers ductile-to-brittle transition temperature dramatically. | | **Chromium (Cr)**| 1.40 - 1.70 | Enhances hardenability, wear/oxidation resistance, and tempering stability. | | **Molybdenum (Mo)** | 0.20 - 0.30 | Increases hardenability, provides solid solution strengthening, and reduces temper embrittlement susceptibility. | | **Manganese (Mn)** | 0.40 - 0.70 | Aids hardenability and deoxidation. | | **Silicon (Si)** | 0.10 - 0.35 | Deoxidizer and solid solution strengthener. | | **Sulfur (S)** | ≤ 0.010 | Ultra-low to maximize transverse ductility and impact strength. | | **Phosphorus (P)** | ≤ 0.015 | Minimized to prevent intergranular embrittlement. | | **Iron (Fe)** | Balance | Matrix. | *Note: The relatively high Nickel content is the key to its exceptional low-temperature toughness.* --- ## **Physical & Mechanical Properties** ### **Typical Mechanical Properties (After Oil Quench & Temper)** *Properties can be tailored across a wide range via tempering temperature.* | Property | 220-240 ksi TS Range | 180-200 ksi TS Range | Units | Condition | |----------|----------------------|----------------------|-------|-----------| | **Tensile Strength** | 220 - 240 | 180 - 200 | ksi | | | **0.2% Yield Strength** | 190 - 210 | 160 - 175 | ksi | | | **Elongation (in 5D)** | 12 - 14 | 14 - 16 | % | | | **Reduction in Area** | 45 - 55 | 50 - 60 | % | | | **Hardness** | 46 - 50 | 38 - 42 | HRC | | | **Charpy V-Notch Impact @ Room Temp** | 40 - 60 | 60 - 80 | ft-lb | *Longitudinal* | | **Charpy V-Notch Impact @ -40°F (-40°C)** | 25 - 40 | 40 - 60 | ft-lb | *Longitudinal* | ### **Fracture Toughness (Typical)** - **K_Ic (Longitudinal):** 150 - 200 ksi√in (165 - 220 MPa√m) at yield strengths of 180-190 ksi. - *The VAC-ARC process provides significantly higher and more consistent toughness than air-melted material, especially in transverse and short-transverse orientations.* ### **Hardenability** - **Excellent Jominy Hardenability:** Capable of achieving full martensitic structure in very large sections (up to **8-10 inches / 200-250 mm** in diameter when oil quenched). ### **Physical Constants** | Property | Value | Units | |----------|-------|--------| | **Density** | 0.284 | lb/in³ (7.86 g/cm³) | | **Modulus of Elasticity** | 29.5 x 10⁶ | psi (203 GPa) | | **Poisson's Ratio** | 0.29 | | | **Thermal Conductivity** | 23.0 | BTU·in/(hr·ft²·°F) at 212°F | | **Coefficient of Thermal Expansion** | 6.5 x 10⁻⁶ | /°F (68-600°F range) | --- ## **International Standards & Specifications** 35NCD16 VAC-ARC conforms to several key international standards, with VAR quality exceeding base requirements. ### **European & International Designations** - **French Standard (AFNOR):** **35NCD16** (Original designation) - **German Standard (DIN/W-Nr.):** **1.6773** (34CrNiMo6 is a close variant) - **UNI (Italy):** **35NiCrMo16 KB** - **Equivalent U.S. / SAE Grade:** Approximate to **4340 Mod.**, but with distinct Ni/Cr balance. ### **Aerospace & Premium Quality Specifications** - **AMS 6419:** Steel Bars, Forgings, and Tubing, 0.35C - 3.25Ni - 1.55Cr - 0.45Mo (0.20-0.30V) Vacuum Melted. *(Closest AMS specification, often used with chemistry alignment)*. - **Customer-Specific:** Often supplied to OEM internal specifications from Airbus, Safran, Leonardo, etc., which detail stringent VAC-ARC requirements. - **MIL-Specs:** Used in defense applications per relevant MIL standards for high-strength forgings. ### **Quality & Testing Compliance** - **AMS 2301:** Premium Aircraft-Quality Steel Cleanliness. - **ASTM A388/A388M:** Standard Practice for Ultrasonic Examination of Heavy Steel Forgings. - **ISO 683-1:** Heat-treatable steels, alloy steels and free-cutting steels – Part 1. - **EN 10228-3:** Non-destructive testing of steel forgings – Part 3: Ultrasonic testing of ferritic or martensitic steel forgings. --- ## **Product Applications** This alloy is specified for components where high strength must be combined with exceptional resistance to shock, fatigue, and brittle fracture. ### **Aerospace** - **Aircraft Landing Gear:** Critical components such as main pistons, trunnions, and drag struts for commercial and military aircraft. - **Helicopter Dynamic Components:** Rotor hubs, mast fittings, and drive shafts. - **Jet Engine Components:** High-stress shafts, discs, and compressor parts. - **Spacecraft & Launch Vehicle Components:** High-integrity structural fittings. ### **Defense** - **Armored Vehicle Components:** Gun mounts, turret rings, and suspension components for tanks and infantry fighting vehicles. - **Naval Applications:** Submarine components, ship shafting, and critical valve bodies. - **Ordnance:** High-stress components in artillery and recoil systems. ### **Energy & Heavy Industry** - **Oil & Gas:** Drill collars, heavy-duty shafts, blowout preventer (BOP) components, and high-pressure fittings for sour service (with proper heat treatment). - **Power Generation:** Turbine shafts, generator rotors, and high-strength fasteners for nuclear and fossil fuel plants. - **Heavy Machinery:** Gears, pinions, and crankshafts for large industrial equipment. --- ## **Manufacturing & Fabrication Guidelines** ### **Recommended Heat Treatment** 1. **Annealing:** Full anneal for optimal machinability (~ 215 HB). 2. **Austenitizing:** 1550 - 1600°F (843 - 871°C) under protective atmosphere to prevent decarburization. 3. **Quenching:** Oil quench is standard for most sections. Very large sections may require intense agitation or polymer quench. 4. **Tempering:** Temper immediately after quenching. Temperature range of **400 - 1200°F (204 - 649°C)** is used to achieve desired properties. Double tempering is strongly recommended. ### **Machining & Fabrication** - **Machining in Annealed State:** Good machinability rating (~60% of 1212 steel) with proper tooling. - **Welding:** Requires stringent procedures: - Preheating: 400-600°F (204-316°C). - Use of low-hydrogen, high-nickel electrodes (e.g., ENiCrMo-type). - Mandatory post-weld heat treatment (PWHT) to temper the heat-affected zone (HAZ) and relieve stresses. - Extensive NDT (UT, MT/PT) post-weld. - **Grinding:** Necessary after heat treatment for final dimensions; careful control to avoid grinding burns. ### **Quality Assurance (VAR-Specific)** - **Complete Melt Documentation:** VAC-ARC remelt log and electrode analysis. - **Ultrasonic Testing:** Per ASTM A388 or EN 10228-3, typically to a stringent acceptance criteria. - **Mechanical Testing:** From both surface and center locations of representative forgings to verify through-properties. - **Impact Testing:** At multiple temperatures (e.g., +20°C, -20°C, -40°C) as required. --- ## **Available Product Forms** - **Primary Forms:** Large diameter forged and rolled bars, heavy forgings (block, shaft, disc, ring), and hollows. - **Sizes:** Typically supplied for heavy-section applications, from ~6 inches (150 mm) up to very large diameters/lengths as required. --- ## **Technical Support** Latrobe’s metallurgical engineering team provides comprehensive support for 35NCD16 VAC-ARC, including: - **Component-Specific Heat Treatment Optimization** - **Welding Procedure Development & Qualification** - **Fracture Mechanics and Fatigue Life Analysis** - **Forging Process Simulation and Design Review** --- **Disclaimer:** The information contained herein is for general reference. For specific design and procurement, consult the official Latrobe Specialty Metals technical data sheets and engage with their application engineering team. Final properties are dependent on exact chemical composition, heat treatment parameters, and section size. This material is subject to international trade compliance regulations. -:- For detailed product information, please contact sales. -: Latrobe Lescalloy® 35NCD16 VAC-ARC High Strength Alloy Steel Specification Dimensions Size： Diameter 20-1000 mm Length <6458 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. -: Latrobe Lescalloy® 35NCD16 VAC-ARC High Strength Alloy Steel Properties -:- For detailed product information, please contact sales. -:

Applications of Latrobe Lescalloy® 35NCD16 VAC-ARC High Strength Alloy Steel Foil -:- For detailed product information, please contact sales. -: Chemical Identifiers Latrobe Lescalloy® 35NCD16 VAC-ARC High Strength Alloy Steel Foil -:- For detailed product information, please contact sales. -:

Packing of Latrobe Lescalloy® 35NCD16 VAC-ARC High Strength Alloy Steel Foil/Strip -:- 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 Foil/Strip 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 2929 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