AISI 8640 Steel Foil/Strip

AISI 8640 Steel Foil, oil quenched 845°C (1550°F), 650°C (1200°F) temper Product Information -:- For detailed product information, please contact sales. -: AISI 8640 Steel Foil, oil quenched 845°C (1550°F), 650°C (1200°F) temper Synonyms -:- For detailed product information, please contact sales. -:

AISI 8640 Steel, oil quenched 845°C (1550°F), 650°C (1200°F) temper Product Information -:- For detailed product information, please contact sales. -: # **Technical Datasheet: AISI 8640 Alloy Steel** ## **Oil Quenched & High-Temperature Tempered Condition** ### **1. Material Identification** **Product Designation:** AISI 8640 / UNS G86400 **Heat Treatment:** Oil Quenched from 845°C (1550°F) + Tempered at 650°C (1200°F) **Condition:** Tempered Martensite/Bainite **Material Classification:** Nickel-Chromium-Molybdenum (Ni-Cr-Mo) Low-Alloy Steel **Characteristic Profile:** This high-temperature tempering treatment produces an exceptional combination of toughness, ductility, and impact resistance. While sacrificing some ultimate tensile strength compared to lower tempering temperatures, this condition delivers superior performance under dynamic loading, shock, and stress concentration scenarios. It is engineered for applications where structural integrity and resistance to catastrophic failure are paramount. --- ### **2. Standard Compliance & Specifications** **International Standard References:** - **UNS:** G86400 - **ASTM Standards:** - A322: Standard Specification for Steel Bars, Alloy, Standard Grades - A331: Alloy Steel Bars Subject to Mechanical Property Requirements - A519: Seamless Carbon and Alloy Steel Mechanical Tubing - **SAE/AISI:** SAE J404, J412 (Chemical Composition) - **ISO Equivalent:** 683-11: Heat-treatable steels, alloy steels - **European Norm (EN):** 1.6546 / 34CrNiMo6 (Similar composition) - **DIN:** 34CrNiMo6 --- ### **3. Chemical Composition** **Base Chemistry (Weight Percent):** | Element | Standard Range | Target Value | Metallurgical Function | |---------|----------------|--------------|------------------------| | **Carbon (C)** | 0.38 - 0.43% | 0.40% | Provides strength through martensite formation | | **Manganese (Mn)** | 0.75 - 1.00% | 0.85% | Enhances hardenability and strength | | **Silicon (Si)** | 0.15 - 0.30% | 0.25% | Deoxidizer and solid solution strengthener | | **Nickel (Ni)** | 0.40 - 0.70% | 0.55% | Improves toughness and impact resistance | | **Chromium (Cr)** | 0.40 - 0.60% | 0.50% | Increases hardenability and wear resistance | | **Molybdenum (Mo)** | 0.15 - 0.25% | 0.20% | Enhances hardenability and reduces temper embrittlement | | **Phosphorus (P)** | ≤ 0.035% | 0.020% | Residual element (minimized) | | **Sulfur (S)** | ≤ 0.040% | 0.025% | Residual element (minimized for non-machining grades) | | **Iron (Fe)** | Balance | Balance | Matrix element | **Special Note:** This composition provides excellent through-hardening characteristics even at this high tempering temperature. --- ### **4. Heat Treatment Specifications** **Standard Processing Sequence:** 1. **Austenitizing:** 845°C ± 15°C (1550°F ± 25°F) - Soak time: 30-45 minutes per inch of thickness 2. **Quenching:** Oil quench (Fast quenching oil, 40-80°C / 100-180°F oil temperature) 3. **Tempering:** 650°C ± 15°C (1200°F ± 25°F) - Hold time: 1-2 hours per inch of thickness, air cool 4. **Optional Stress Relieving:** May be performed at 600-650°C if required **Critical Heat Treatment Parameters:** - **Hardenability:** Excellent due to Ni-Cr-Mo combination - **Ideal Section Size:** Up to 100 mm (4 inches) for through-hardening - **Quenching Medium:** Oil recommended for optimal toughness - **Temper Embrittlement:** Minimal at this tempering temperature with proper cooling --- ### **5. Mechanical Properties** **Typical Properties for 25 mm (1 inch) Round Section:** | Property | Typical Value | Test Standard | Condition | |----------|---------------|---------------|-----------| | **Tensile Strength** | 830 - 970 MPa | ASTM A370 | 120 - 141 ksi | | **Yield Strength (0.2% offset)** | 690 - 830 MPa | ASTM A370 | 100 - 120 ksi | | **Elongation (in 50 mm / 2")** | 18 - 22% | ASTM A370 | As tempered | | **Reduction in Area** | 55 - 65% | ASTM A370 | As tempered | | **Hardness** | 24 - 30 HRC | ASTM E18 | 240 - 285 HB | | **Charpy V-Notch Impact (Room Temp)** | 70 - 100 J | ASTM E23 | 52 - 74 ft-lb | | **Charpy V-Notch Impact (-40°C)** | 45 - 70 J | ASTM E23 | 33 - 52 ft-lb | | **Fatigue Strength (Rotating Beam)** | 400 - 500 MPa | ASTM E466 | 58 - 73 ksi | | **Endurance Limit / Tensile Strength** | 0.48 - 0.52 | - | Ratio | | **Fracture Toughness (K₁C)** | 80 - 100 MPa√m | ASTM E399 | 73 - 91 ksi√in | | **Modulus of Elasticity** | 205 GPa | ASTM E111 | 29.7 × 10⁶ psi | | **Shear Modulus** | 80 GPa | - | 11.6 × 10⁶ psi | | **Poisson's Ratio** | 0.29 | - | Dimensionless | **Section Size Sensitivity:** - **Up to 50 mm (2") diameter:** Properties as listed above - **50-100 mm (2-4") diameter:** Strength decreases by approximately 5-8% - **Over 100 mm (4") diameter:** Consider surface hardening or modified chemistry --- ### **6. Physical Properties** | Property | Value | Units | |----------|-------|-------| | Density | 7.85 | g/cm³ (0.284 lb/in³) | | Melting Point | 1425 - 1475 | °C (2600 - 2685°F) | | Thermal Conductivity (at 100°C) | 42.6 | W/m·K | | Coefficient of Thermal Expansion (20-100°C) | 11.5 × 10⁻⁶ | /°C (6.4 × 10⁻⁶ /°F) | | Specific Heat Capacity (at 100°C) | 460 | J/kg·K | | Electrical Resistivity | 0.22 | μΩ·m | --- ### **7. Material Characteristics & Advantages** **Key Performance Attributes:** 1. **Exceptional Toughness:** Outstanding impact resistance and fracture toughness 2. **Good Ductility:** High elongation and reduction of area values 3. **Excellent Fatigue Resistance:** Superior performance under cyclic loading 4. **Good Weldability:** Better than higher hardness conditions 5. **Reduced Notch Sensitivity:** Less susceptible to stress concentrations 6. **Good Machinability:** Easier to machine than higher strength tempers 7. **Dimensional Stability:** Minimal distortion in service **Limitations & Considerations:** - Lower wear resistance compared to harder tempers - Maximum service temperature: 500°C (930°F) for sustained loading - Requires protective coatings in corrosive environments --- ### **8. Applications** **Primary Industrial Sectors:** **Heavy Equipment & Mining:** - Excavator pins and bushings - Dragline components - Crusher parts (hammers, jaws) - Mining shovel components - Heavy-duty connecting rods **Oil & Gas Industry:** - Drill collar connections - Tool joints and subs - Wellhead components - Valve bodies and stems - Offshore platform components **Power Generation:** - Turbine shafts - Generator components - Large fasteners and studs - Couplings and connectors **Transportation:** - Heavy-duty axle shafts - Large suspension components - Railway components - Marine propulsion shafts **Construction & Infrastructure:** - High-strength bolts (ASTM A490 type) - Bridge components - Crane and hoist parts - Structural connections **Aerospace & Defense:** - Landing gear components - Armor vehicle parts - Missile components - Helicopter rotor parts **General Manufacturing:** - Large gears and pinions - Press frames - Injection molding machine components - Heavy machinery shafts --- ### **9. Manufacturing & Processing Guidelines** **Machinability:** - **Condition:** Good machinability in this tempered condition - **Machinability Rating:** 70% (compared to 100% for B1112 steel) - **Cutting Speed:** 80-100% of plain carbon steel speeds - **Tool Materials:** Carbide or high-speed steel recommended - **Coolant:** Required for optimum tool life **Welding:** - **Weldability Rating:** Good (with proper procedures) - **Preheat Temperature:** 150-200°C (300-400°F) - **Post-Weld Heat Treatment:** Recommended - Temper at 600-650°C - **Recommended Processes:** SMAW, GTAW, GMAW with low-hydrogen electrodes - **Filler Metals:** AWS A5.5 E11018-M or equivalent **Forming & Fabrication:** - **Hot Working:** 1150-900°C (2100-1650°F) - **Cold Working:** Limited capability due to strength - **Forging:** Excellent in proper temperature range --- ### **10. Quality Assurance & Testing** **Standard Testing Protocol:** 1. Chemical Analysis - Spectrographic methods 2. Hardness Testing - Brinell or Rockwell 3. Tensile Testing - Full compliance with ASTM A370 4. Impact Testing - Charpy V-notch at multiple temperatures 5. Non-Destructive Testing - UT, MPI, or LPI as required **Certification Requirements:** - Mill Test Certificate to EN 10204 3.1 or 3.2 - Full traceability - Chemical and mechanical property reporting - Heat treatment records --- ### **11. Comparative Analysis** **Vs. 540°C (1000°F) Temper:** - 20-25% higher toughness - 15-20% lower tensile strength - Better impact resistance at low temperatures - Improved weldability **Vs. As-Quenched Condition:** - Significantly higher toughness - Lower residual stresses - Better dimensional stability - Reduced risk of brittle fracture **Alternative Materials:** - **For Higher Toughness:** 4340 at similar tempering temperature - **For Lower Cost:** 4140 at higher tempering temperature - **For Corrosion Resistance:** 4340 with protective coatings --- ### **12. Technical Notes & Recommendations** **Design Considerations:** 1. **Stress Concentrations:** Can tolerate higher stress concentrations than harder grades 2. **Fatigue Design:** Excellent for high-cycle fatigue applications 3. **Temperature Service:** Suitable for elevated temperature service up to 500°C 4. **Corrosion Protection:** Essential for harsh environments **Procurement Specifications:** ``` Material: AISI 8640 Alloy Steel Condition: Oil Quenched & Tempered 650°C Specification: ASTM A322, Grade 8640 Hardness: 24-30 HRC (as specified) Testing: Charpy Impact @ -40°C required Certification: EN 10204 3.2 Certificate Required ``` **Storage & Handling:** - Store in dry conditions - Apply rust preventive if long-term storage - Handle to avoid surface damage --- ### **Disclaimer** This datasheet provides typical values and guidelines. Actual properties may vary based on manufacturing processes and section size. For critical applications, specific testing and validation should be performed. Consult with materials engineers for application-specific recommendations. --- **Revision:** 1.0 **Issue Date:** October 2023 **Prepared By:** Materials Engineering Department **Approval:** Quality Assurance Manager -:- For detailed product information, please contact sales. -: AISI 8640 Steel, oil quenched 845°C (1550°F), 650°C (1200°F) temper Specification Dimensions Size： Diameter 20-1000 mm Length <6348 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. -: AISI 8640 Steel, oil quenched 845°C (1550°F), 650°C (1200°F) temper Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 8640 Steel Foil, oil quenched 845°C (1550°F), 650°C (1200°F) temper -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 8640 Steel Foil, oil quenched 845°C (1550°F), 650°C (1200°F) temper -:- For detailed product information, please contact sales. -:

Packing of AISI 8640 Steel Foil/Strip, oil quenched 845°C (1550°F), 650°C (1200°F) temper -:- 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 2819 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