AISI 4140 Steel Sheet,Plate

AISI 4140 Steel Sheet/Plate, annealed at 815°C (1500°F) furnace cooled 11°C (20°F)/hour to 665°C (1230°F), air cooled, 25 mm (1 in.) round Product Information -:- For detailed product information, please contact sales. -: AISI 4140 Steel Sheet/Plate, annealed at 815°C (1500°F) furnace cooled 11°C (20°F)/hour to 665°C (1230°F), air cooled, 25 mm (1 in.) round Synonyms -:- For detailed product information, please contact sales. -:

AISI 4140 Steel, annealed at 815°C (1500°F) furnace cooled 11°C (20°F)/hour to 665°C (1230°F), air cooled, 25 mm (1 in.) round Product Information -:- For detailed product information, please contact sales. -: # **AISI 4140 Steel - Annealed Product Specification** ## **1. Product Definition & Processing History** This specification covers **AISI 4140** alloy steel supplied as **25 mm (1 inch) diameter round bars** processed to a fully annealed condition. **Specific Annealing Cycle:** - **Austenitizing:** 815°C (1500°F) - **Cooling Rate:** Controlled furnace cooling at 11°C/hour (20°F/hour) to 665°C (1230°F) - **Final Cooling:** Air-cooled from 665°C (1230°F) - **Product Form:** Hot-rolled or cold-drawn round bar - **Condition:** Fully annealed to achieve maximum softness and machinability This specific annealing cycle with controlled slow cooling produces a coarse pearlitic-ferritic microstructure that optimizes machinability by ensuring uniform softness throughout the 25 mm cross-section. ## **2. International Standards & Designations** - **Primary Standard:** ASTM A29/A29M (Standard Specification for Steel Bars, Carbon and Alloy) - **Material Designation:** AISI 4140 - **UNS Designation:** G41400 - **European Equivalent:** 1.7225 (42CrMo4) per EN 10083-3 - **Japanese Equivalent:** SCM440 per JIS G4105 - **Chinese Equivalent:** 42CrMo per GB/T 3077 - **ISO Equivalent:** 42CrMo4 (ISO 683-18) - **Processing Standard:** Annealing per ASTM A29, Grade Annealed ## **3. Chemical Composition (Weight %)** | Element | Composition Range (%) | Typical Aim (%) | Function in 4140 | |---------|----------------------|-----------------|------------------| | **Carbon (C)** | 0.38 - 0.43 | 0.40 | Primary strengthener, provides hardenability | | **Manganese (Mn)** | 0.75 - 1.00 | 0.85 | Increases hardenability and strength | | **Phosphorus (P)** | ≤ 0.035 | 0.020 | Residual element (controlled) | | **Sulfur (S)** | ≤ 0.040 | 0.025 | Improves machinability (controlled) | | **Silicon (Si)** | 0.15 - 0.35 | 0.25 | Deoxidizer, strengthens ferrite | | **Chromium (Cr)** | 0.80 - 1.10 | 0.95 | Enhances hardenability, wear, and corrosion resistance | | **Molybdenum (Mo)** | 0.15 - 0.25 | 0.20 | Increases hardenability, high-temperature strength, reduces temper embrittlement | **Note:** The controlled slow cooling from 815°C to 665°C allows maximum softening by promoting coarse pearlite formation and minimizing residual stresses. ## **4. Physical Properties (Annealed Condition)** - **Density:** 7.85 g/cm³ (0.284 lb/in³) - **Melting Range:** 1416-1510°C (2580-2750°F) - **Modulus of Elasticity:** 205 GPa (29.7 × 10⁶ psi) - **Shear Modulus:** 80 GPa (11.6 × 10⁶ psi) - **Poisson's Ratio:** 0.29 - **Thermal Conductivity:** 42.6 W/m·K at 100°C - **Specific Heat Capacity:** 473 J/kg·K at 20°C - **Coefficient of Thermal Expansion:** 11.9 µm/m·°C (20-100°C) - **Electrical Resistivity:** 0.22 µΩ·m at 20°C ## **5. Mechanical Properties (Annealed at 815°C, Controlled Cooled)** *Minimum guaranteed properties for 25 mm (1 in.) diameter in fully annealed condition:* | Property | Value | Test Standard | |----------|-------|--------------| | **Tensile Strength** | 655 MPa (95 ksi) min | ASTM A370 | | **Yield Strength (0.2% offset)** | 415 MPa (60 ksi) min | ASTM A370 | | **Elongation in 50 mm (2 in.)** | 25.5% min | ASTM A370 | | **Reduction of Area** | 50% min | ASTM A370 | | **Hardness (Brinell)** | 197-223 HB | ASTM E10 | | **Hardness (Rockwell)** | 92-100 HRB | ASTM E18 | | **Hardness (typical)** | 207 HB (typical) | - | | **Impact Energy (Charpy V-notch)** | 54 J (40 ft-lb) min at 20°C | ASTM A370 | **Typical Properties (Average):** - **Ultimate Tensile Strength:** 690 MPa (100 ksi) - **Yield Strength:** 490 MPa (71 ksi) - **Elongation:** 28% - **Reduction of Area:** 55% ## **6. Metallurgical Characteristics** - **Microstructure:** Coarse pearlite and ferrite (fully annealed structure) - **Grain Size:** ASTM 5-7 - **Prior Austenite Grain Size:** ASTM 6 or coarser due to slow cooling - **Decarburization:** ≤ 0.38 mm (0.015 in.) total depth on diameter - **Surface Quality:** Free from seams, cracks, and other injurious defects per ASTM A29 - **Microstructure Uniformity:** Excellent throughout 25 mm cross-section due to controlled cooling rate ## **7. Machinability & Manufacturing Characteristics** ### **Machinability** - **Relative Machinability:** 65% (compared to 100% for B1112 steel) - **Machinability Rating:** Good for a medium-carbon alloy steel - **Recommended Cutting Speeds:** - Turning: 35-50 m/min (115-165 ft/min) with carbide tools - Drilling: 20-25 m/min (65-80 ft/min) with HSS drills - Milling: 30-40 m/min (100-130 ft/min) with carbide end mills - **Tool Material Recommendations:** Carbide preferred, C2/C6 grades for roughing, C5/C6 for finishing - **Chip Formation:** Produces discontinuous chips - use chipbreakers - **Coolant:** Highly recommended for extended tool life ### **Further Processing Compatibility** - **Subsequent Heat Treatment:** Excellent candidate for quenching and tempering to higher strengths - **Weldability:** Fair to good with proper precautions (preheat to 150-260°C/300-500°F, post-weld heat treat) - **Forgability:** Good - heat to 1150-1230°C (2100-2250°F), finish above 870°C (1600°F) - **Cold Forming:** Moderate - limited by medium carbon content - **Surface Hardening:** Suitable for induction hardening, flame hardening, and nitriding ## **8. Hardenability Characteristics** - **Ideal Critical Diameter (Dᵢ):** ~3.0 inches (76 mm) for oil quenching - **Jominy Curve Position:** Hardness of ~55 HRC at J1 distance after oil quench - **Through-Hardening Capability:** Full hardening achievable in 25 mm diameter with proper quench - **Hardenability Band:** Not guaranteed (non-H grade), but typically consistent due to standardized chemistry ## **9. Product Applications** This annealed 4140 product is particularly suitable for: ### **Machinery Components** - **Gears and pinions** (prior to final heat treatment) - **Shafts and axles** requiring extensive machining - **Machine tool components** - **Die holders and tooling bases** ### **Automotive & Heavy Equipment** - **Crankshafts and camshafts** (forging/machining before hardening) - **Axle shafts** - **Gear blanks** - **Suspension components** ### **Oil & Gas Industry** - **Valve bodies and components** - **Downhole tooling** - **Drilling equipment parts** ### **General Manufacturing** - **Jigs and fixtures** - **Press tools** - **High-strength fasteners** (prior to heat treatment) - **Hydraulic cylinder components** ## **10. Advantages of This Specific Annealed Product** 1. **Maximum Machinability:** Controlled slow cooling produces the softest possible condition for AISI 4140 2. **Uniform Properties:** 11°C/hour cooling ensures consistent microstructure throughout 25 mm cross-section 3. **Minimal Residual Stress:** Slow cooling minimizes internal stresses that can cause distortion during machining 4. **Predictable Tool Life:** Consistent hardness allows accurate prediction of machining parameters 5. **Ideal Heat Treatment Base:** Provides consistent starting point for subsequent hardening operations 6. **Excellent Chip Formation:** Optimized microstructure produces favorable chips for automated machining ## **11. Quality Assurance** - **Mill Certification:** Provided with each shipment including chemical analysis and mechanical properties - **Traceability:** Heat/lot traceability maintained - **Surface Inspection:** Visually inspected per ASTM A29 requirements - **Dimensional Tolerance:** ±0.5 mm (±0.020 in.) on 25 mm diameter - **Straightness:** ≤ 1.0 mm/m (≤ 0.012 in./ft) - **Testing Frequency:** Per ASTM A29 requirements for annealed bars ## **12. Storage & Handling** - **Storage Conditions:** Dry, indoor environment to prevent corrosion - **Surface Protection:** Light oil coating applied for corrosion protection - **Handling:** Standard material handling practices apply - **Shelf Life:** Indefinite when properly stored - **Identification:** Heat numbers marked on bundles or individual bars ## **13. Safety & Environmental** - **Machining:** Use appropriate PPE (safety glasses, hearing protection) and ventilation for metal dust - **Disposal:** Recyclable as ferrous scrap - **Compliance:** Meets RoHS and REACH requirements - **Material Safety:** No special hazards beyond those typical of alloy steels ## **14. Technical Notes** 1. **Annealing Rationale:** The 11°C/hour cooling rate from 815°C to 665°C allows maximum transformation to coarse pearlite, producing optimal machinability 2. **Diameter Consideration:** 25 mm diameter ensures complete transformation throughout cross-section with this cooling rate 3. **Post-Machining Heat Treatment:** After machining, components can be hardened to various strength levels: - 855°C (1570°F) oil quench + 205°C (400°F) temper → 1790 MPa (260 ksi) tensile - 855°C (1570°F) oil quench + 540°C (1000°F) temper → 1030 MPa (150 ksi) tensile 4. **Cost Efficiency:** Supplying pre-annealed material eliminates need for customer annealing, reducing overall processing time and cost 5. **Consistency:** The controlled furnace cooling ensures batch-to-batch consistency superior to air-cooled normalization --- **Disclaimer:** This specification is for informational purposes. Final material selection should be based on specific application requirements and consultation with qualified engineering personnel. Properties may vary based on manufacturing process, exact cooling conditions, and testing methods. Users should verify properties for critical applications through appropriate testing. -:- For detailed product information, please contact sales. -: AISI 4140 Steel, annealed at 815°C (1500°F) furnace cooled 11°C (20°F)/hour to 665°C (1230°F), air cooled, 25 mm (1 in.) round Specification Dimensions Size： Diameter 20-1000 mm Length <4040 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 4140 Steel, annealed at 815°C (1500°F) furnace cooled 11°C (20°F)/hour to 665°C (1230°F), air cooled, 25 mm (1 in.) round Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 4140 Steel Sheet,Plate, annealed at 815°C (1500°F) furnace cooled 11°C (20°F)/hour to 665°C (1230°F), air cooled, 25 mm (1 in.) round -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 4140 Steel Sheet,Plate, annealed at 815°C (1500°F) furnace cooled 11°C (20°F)/hour to 665°C (1230°F), air cooled, 25 mm (1 in.) round -:- For detailed product information, please contact sales. -:

Packing of AISI 4140 Steel Sheet/Plate, annealed at 815°C (1500°F) furnace cooled 11°C (20°F)/hour to 665°C (1230°F), air cooled, 25 mm (1 in.) round -:- 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 511 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