AISI 4620 Steel Foil/Strip,

AISI 4620 Steel Foil, annealed, 25 mm round Product Information -:- For detailed product information, please contact sales. -: AISI 4620 Steel Foil, annealed, 25 mm round Synonyms -:- For detailed product information, please contact sales. -:

AISI 4620 Steel, annealed, 25 mm round Product Information -:- For detailed product information, please contact sales. -: # **AISI 4620 Alloy Steel - Annealed Round Bar** ## **25mm Diameter, Nickel-Molybdenum Case-Hardening Steel** --- ### **1. PRODUCT OVERVIEW** **AISI 4620 Alloy Steel - Annealed Condition** - **Product Form:** 25mm (1.0 inch) diameter round bar - **Material Standard:** AISI 4620 / SAE 4620 - **Condition:** Annealed (full anneal or spheroidize annealed) - **Material Type:** Low-carbon nickel-molybdenum alloy steel - **Primary Application:** Case hardening (carburizing or carbonitriding) - **Key Characteristic:** Excellent core toughness with hard wear-resistant surface after case hardening - **Typical Supply:** Annealed for optimal machinability prior to heat treatment **Material Designation Breakdown:** - **"46" Series:** Nickel-molybdenum alloy steels - **"20":** Nominal carbon content of 0.20% - **Annealed Condition:** Soft state for machining, hardness 149-197 HB - **25mm Round:** Standard industrial size for shafting, gears, and general components --- ### **2. CHEMICAL COMPOSITION** | Element | AISI 4620 Standard Range (%) | Typical Annealed Bar Composition (%) | Metallurgical Function | |---------|-----------------------------|--------------------------------------|------------------------| | **Carbon (C)** | 0.17-0.22 | 0.18-0.20 | Base strength, carburizing response control | | **Manganese (Mn)** | 0.45-0.65 | 0.50-0.60 | Hardenability enhancement, deoxidation | | **Phosphorus (P)** | ≤ 0.035 | ≤ 0.020 | Residual impurity (strictly controlled) | | **Sulfur (S)** | ≤ 0.040 | 0.025-0.035 | Machinability enhancer (often at higher end) | | **Silicon (Si)** | 0.15-0.30 | 0.20-0.25 | Deoxidizer, solid solution strengthening | | **Nickel (Ni)** | 1.65-2.00 | 1.70-1.85 | **Primary alloy:** Provides exceptional core toughness | | **Molybdenum (Mo)** | 0.20-0.30 | 0.22-0.27 | **Secondary alloy:** Grain refinement, hardenability | | **Chromium (Cr)** | - | ≤ 0.20 | Trace residual (not specified but typically present) | | **Copper (Cu)** | - | ≤ 0.35 | Trace residual | | **Aluminum (Al)** | - | 0.010-0.040 | Grain size control (if used) | | **Iron (Fe)** | Balance | Balance | Matrix element | **Composition Design Philosophy for 4620:** - **Optimal Carbon for Case Hardening:** 0.20% nominal allows deep case formation without excessive core brittleness - **Nickel Content:** High (1.8% nominal) for superior impact resistance in core - **Molybdenum Addition:** Provides grain control and tempering stability - **Balance:** Optimized for both machinability (annealed) and heat treatment response --- ### **3. INTERNATIONAL STANDARDS & EQUIVALENTS** | Standard System | Designation | Title / Description | Application Scope | |----------------|-------------|---------------------|-------------------| | **UNS** | G46200 | Unified Numbering System | Primary US designation | | **AISI/SAE** | 4620 | SAE J404, J412 | Original specification | | **ASTM** | A322 | Standard Specification for Steel Bars, Alloy | Grade 4620 | | **ASTM** | A29/A29M | Steel Bars, Carbon and Alloy, Hot-Wrought and Cold-Finished | Dimensional standards | | **AMS** | 6270 | Steel Bars and Forgings, 1.8Ni-0.25Mo (0.18-0.23C) | Aerospace quality | | **ISO** | 683-11 | Heat-treatable steels | 20NiCrMo2-2 equivalent | | **DIN** | 1.6523 | 20NiCrMo2-2 | German equivalent | | **EN** | 1.6523 | 20NiCrMo2-2 | European standard | | **JIS** | SNCM220 | Nickel-chromium-molybdenum steel | Japanese similar grade | | **GB** | 20Ni2Mo | Chinese standard | Chinese equivalent | **25mm Round Bar Specific Standards:** - **Diameter Tolerance:** Typically ±0.15mm per ASTM A29 - **Straightness:** 0.5mm per 300mm typical - **Surface Finish:** As-annealed, typically 3.2-6.3μm Ra - **Length:** Standard 3-6 meters; cut to length available --- ### **4. PHYSICAL PROPERTIES (ANNEALED CONDITION)** | Property | Value | Conditions / Notes | |----------|-------|-------------------| | **Density** | 7.85 g/cm³ (0.284 lb/in³) | At 20°C, typical for alloy steels | | **Melting Range** | 1480-1520°C | Liquidus to solidus temperature | | **Thermal Conductivity** | 42.5 W/m·K | At 100°C, annealed condition | | **Specific Heat Capacity** | 460 J/kg·K | At 20°C | | **Coefficient of Thermal Expansion** | 12.3 × 10⁻⁶/K | 20-100°C temperature range | | **Electrical Resistivity** | 0.22 μΩ·m | At 20°C | | **Modulus of Elasticity** | 205 GPa (29.7×10⁶ psi) | Typical for steel | | **Shear Modulus** | 80 GPa (11.6×10⁶ psi) | - | | **Poisson's Ratio** | 0.29 | Standard value for steel | | **Magnetic Properties** | Ferromagnetic | Below Curie temperature (~770°C) | **Annealing Transformation Characteristics:** - **Ac₁:** ~735°C (1355°F) - **Ac₃:** ~805°C (1480°F) - **Annealing Temperature:** 830-850°C (1525-1560°F) - **Cooling Rate:** Furnace cool to 600°C at ≤25°C/hour --- ### **5. MECHANICAL PROPERTIES (ANNEALED CONDITION)** #### **As-Annealed Properties for 25mm Round:** | Property | Value Range | Testing Standard | Application Significance | |----------|-------------|------------------|--------------------------| | **Hardness** | 149-197 HB (85-93 HRB) | ASTM E10 | Optimized for machining | | **Tensile Strength** | 500-650 MPa (73-94 ksi) | ASTM E8/E8M | Adequate for handling and initial assembly | | **Yield Strength (0.2%)** | 350-450 MPa (51-65 ksi) | ASTM E8/E8M | Sufficient for pre-hardening assembly | | **Elongation in 4D** | 25-30% | ASTM E8/E8M | Excellent ductility for forming | | **Reduction of Area** | 50-60% | ASTM E8/E8M | High energy absorption capacity | | **Machinability Rating** | 65-70% of B1112 steel | Comparative | Good machinability for alloy steel | | **Modulus of Elasticity** | 205 GPa (29.7×10⁶ psi) | - | Unaffected by annealing | #### **Expected Properties After Case Hardening:** | Property | Case Region | Core Region | |----------|-------------|------------| | **Hardness** | 58-63 HRC | 30-40 HRC | | **Tensile Strength** | - | 850-1000 MPa | | **Yield Strength** | - | 650-800 MPa | | **Charpy Impact** | - | 40-60 J (core) | | **Case Depth (typical)** | 0.5-1.5mm at 550 HV | - | --- ### **6. MICROSTRUCTURAL CHARACTERISTICS** #### **As-Annealed Microstructure:** - **Primary Phase:** Ferrite matrix with spheroidized carbides - **Grain Size:** ASTM 5-7 (fine to medium) - **Carbide Morphology:** Spheroidal, uniformly distributed - **Inclusion Content:** Typically low (ASTM E45 rating 1.0-1.5 worst field) - **Uniformity:** Consistent throughout 25mm cross-section #### **Annealing Process for 25mm Rounds:** 1. **Heating:** 830-850°C (1525-1560°F) in controlled atmosphere 2. **Soaking:** 60-90 minutes for complete transformation 3. **Cooling:** Furnace cool to 600°C at 20-30°C/hour 4. **Final Cooling:** Air cool to room temperature 5. **Result:** Spheroidized structure optimal for machining --- ### **7. HEAT TREATMENT RESPONSE** #### **Recommended Case Hardening Process:** 1. **Carburizing (Typical):** - Temperature: 900-925°C (1650-1700°F) - Atmosphere: Endothermic gas with natural gas enrichment - Time: Varies for desired case depth (typically 4-8 hours for 0.5-1.0mm) - Surface Carbon: 0.70-0.90% 2. **Quenching:** - Temperature: Direct quench from carburizing or reheat to 815-845°C (1500-1550°F) - Medium: Fast oil quench - Agitation: Moderate for 25mm section 3. **Tempering:** - Temperature: 150-200°C (300-400°F) - Time: 1-2 hours - Purpose: Stress relief, slight toughness improvement #### **Hardenability Data (Jominy Test - Typical):** | Distance from Quenched End | Hardness (HRC) | Microstructure | |----------------------------|----------------|---------------| | **1.5 mm (1/16")** | 35-40 | 80-90% martensite | | **5 mm (3/16")** | 30-35 | 60-80% martensite | | **10 mm (3/8")** | 25-30 | 40-60% martensite | | **15 mm (5/8")** | 22-27 | 20-40% martensite | | **Center of 25mm round** | 20-25 | Predicted from Jominy data | --- ### **8. TYPICAL APPLICATIONS** #### **Automotive Components (Primary Market):** - **Transmission Parts:** Gears, synchronizer hubs, shift forks - **Steering Systems:** Rack and pinion gears, steering shafts - **Engine Components:** Camshafts, rocker arms, valve lifters - **Drive Train:** Differential gears, spider gears, drive pinions - **Fasteners:** High-strength bolts and studs (after heat treatment) #### **Aerospace and Defense:** - **Landing Gear Components:** Bushings, pins, brackets - **Actuator Systems:** Gears, shafts, lever arms - **Engine Accessories:** Gearbox components - **Control Systems:** Precision mechanism parts #### **Industrial Machinery:** - **Gear Manufacturing:** Industrial gear sets, pinions - **Power Transmission:** Sprockets, chain wheels, couplings - **Heavy Equipment:** Construction machinery components - **Agricultural Machinery:** Gearbox parts, PTO shafts #### **General Engineering:** - **Shafting:** General purpose shafts and axles - **Wear Components:** Bushings, sleeves, wear plates (after hardening) - **Tooling:** Jigs, fixtures, die components - **Fastening Systems:** High-strength threaded components #### **Why 25mm Annealed Round Bar is Popular:** 1. **Versatile Size:** Suitable for wide range of components 2. **Machining Efficiency:** Optimal chip load for turning operations 3. **Heat Treatment Uniformity:** Good case depth control 4. **Material Utilization:** Minimal waste in typical component designs --- ### **9. PROCESSING CHARACTERISTICS (ANNEALED CONDITION)** #### **Machinability:** - **Relative Rating:** 65-70% of B1112 free-cutting steel - **Optimum Cutting Speed:** 40-70 m/min for turning - **Feed Rate:** 0.15-0.30 mm/rev for roughing, 0.05-0.15 mm/rev for finishing - **Tool Materials:** Carbide recommended for production; HSS suitable - **Chip Formation:** Continuous chips with proper tool geometry - **Surface Finish:** Good (1.6-3.2μm Ra achievable) - **Coolant:** Recommended for optimal tool life and finish #### **Forming and Cold Working:** - **Cold Formability:** Good in annealed condition - **Bending:** Minimum bend radius ~2× diameter - **Heading/Extrusion:** Suitable for cold forming operations - **Annealing Between Operations:** Recommended for severe deformation #### **Welding (in Annealed Condition):** - **Weldability Rating:** Fair to Good - **Preheat:** 150-200°C recommended for thickness >12mm - **Methods:** GTAW (TIG), GMAW (MIG), SMAW with low-hydrogen electrodes - **Post-Weld:** Stress relief at 590-650°C recommended if welding before case hardening - **Note:** Welding after case hardening is generally not recommended #### **Grinding and Finishing:** - **As-Annealed:** Good grindability with proper wheels - **After Hardening:** Requires appropriate abrasive selection - **Surface Preparation:** Good base for plating or coating --- ### **10. QUALITY ASSURANCE** #### **Standard Testing for Annealed Bars:** 1. **Chemical Analysis:** Spectrographic verification per heat 2. **Hardness Testing:** Multiple points along bar length (ASTM E10) 3. **Surface Inspection:** Visual for seams, laps, cracks 4. **Dimensional Verification:** Diameter, roundness, straightness 5. **Microstructure Check:** Spheroidized structure verification (sample basis) #### **Typical Quality Parameters for 25mm Annealed Rounds:** | Parameter | Standard Requirement | Typical Value | |-----------|---------------------|---------------| | **Hardness Uniformity** | Within 20 HB points | Within 15 HB points | | **Decarburization** | ≤0.25mm depth | ≤0.15mm depth | | **Surface Defects** | No cracks or seams | Clean surface | | **Straightness** | ≤1mm per meter | ≤0.5mm per meter | | **Diameter Tolerance** | ±0.15mm | ±0.10mm | #### **Certification Provided:** - Material Test Certificate 3.1 per EN 10204 - Chemical analysis report - Heat treatment record (annealing) - Dimensional inspection report --- ### **11. COMPARISON WITH SIMILAR GRADES** | Grade | C% Range | Ni% Range | Condition | Hardness (HB) | Primary Application | |-------|----------|-----------|-----------|--------------|---------------------| | **AISI 4620 Annealed** | 0.17-0.22 | 1.65-2.00 | Annealed | 149-197 | General case hardening | | **AISI 8620 Annealed** | 0.18-0.23 | 0.40-0.70 | Annealed | 149-197 | General purpose, lower cost | | **AISI 4118 Annealed** | 0.18-0.23 | - | Annealed | 156-207 | Cost-sensitive applications | | **AISI 5120 Annealed** | 0.17-0.22 | - | Annealed | 149-197 | General machinery | | **AISI 9310 Annealed** | 0.08-0.13 | 3.00-3.50 | Annealed | 149-197 | High-performance aerospace | **Selection Guidelines for 25mm Components:** - **Choose 4620 over 8620:** When superior core toughness is required - **Choose 4620 over 4118/5120:** When nickel toughness is needed - **Choose 4620 over 9310:** For cost-sensitive applications with good performance - **Consider H-grade (4620H):** When hardenability consistency is critical --- ### **12. DESIGN CONSIDERATIONS** #### **For 25mm Diameter Components:** 1. **Case Depth Recommendations:** - Light duty: 0.3-0.6mm case depth - Medium duty: 0.6-1.0mm case depth - Heavy duty: 1.0-1.5mm case depth - Maximum recommended: ~1.5mm for 25mm diameter 2. **Core Properties After Hardening:** - Hardness: 30-40 HRC - Strength: 850-1000 MPa UTS - Toughness: Excellent (40-60J Charpy) 3. **Distortion Considerations:** - Predictable for 25mm sections - Allow 0.1-0.2mm per 25mm for machining allowance - Symmetrical designs minimize distortion #### **Design Best Practices:** - **Fillets and Radii:** Minimum 1mm radius on corners - **Section Changes:** Gradual transitions to avoid stress concentrations - **Surface Finish:** Machine to 1.6-3.2μm Ra before case hardening - **Dimensional Allowance:** Include 0.1-0.3mm for grinding after hardening --- ### **13. STORAGE AND HANDLING** #### **Packaging for 25mm Annealed Bars:** - **Standard Bundles:** 1-3 metric tons, strapped - **Protection:** Rust preventive oil or VCI paper - **Identification:** Heat number, grade, size marked on tags - **End Marking:** Color coded for grade identification #### **Storage Recommendations:** - **Environment:** Dry, temperature controlled - **Stacking:** Proper support to prevent bending - **Shelf Life:** Indefinite if protected from corrosion - **Handling:** Use appropriate equipment to prevent surface damage #### **Rust Prevention:** - **As-supplied:** Typically coated with rust preventive oil - **In-process:** Maintain protection during storage - **Long-term:** Consider VCI packaging or controlled humidity storage --- ### **14. ECONOMIC AND PROCUREMENT CONSIDERATIONS** #### **Cost Factors:** - **Material Cost:** Moderate (higher than plain carbon, lower than high-nickel grades) - **Availability:** Widely available from steel service centers - **Lead Time:** Typically stock item for 25mm rounds - **Minimum Order:** Usually 500kg-1000kg for specific heats #### **Procurement Specification Example:** ``` MATERIAL: AISI 4620 Annealed Round Bar SIZE: 25mm diameter ±0.15mm CONDITION: Fully annealed, 149-197 HB LENGTH: 3000mm ±10mm, cut edges deburred QUANTITY: [Specify quantity] meters CERTIFICATION: EN 10204 3.1 certificate required PACKAGING: Bundled with rust prevention, clearly marked ``` #### **Supplier Qualification:** - ISO 9001 certification - Capability to provide full traceability - Consistent quality history - Technical support availability --- **MATERIAL SELECTION SUMMARY:** AISI 4620 in annealed 25mm round bar form offers an excellent combination of machinability and subsequent heat treatment potential. The nickel-molybdenum composition provides superior core toughness after case hardening, making it ideal for components subject to impact loading or fatigue. The 25mm diameter is versatile for a wide range of mechanical components in automotive, industrial, and general engineering applications. **KEY PROCESSING RECOMMENDATIONS:** 1. **Machine in annealed condition** for optimal tool life and surface finish 2. **Allow for heat treatment distortion** in dimensional planning 3. **Consider case depth requirements** early in design phase 4. **Utilize the excellent core toughness** in component design **HEAT TREATMENT EXPECTATIONS:** For 25mm diameter components: - Carburize at 925°C for desired case depth - Oil quench from 825°C - Temper at 175°C for 2 hours - Expected case hardness: 58-62 HRC - Expected core hardness: 32-38 HRC --- **QUALITY ASSURANCE STATEMENT:** This AISI 4620 annealed round bar is produced to meet or exceed the requirements of ASTM A322 and SAE J404/J412. The material is supplied with full traceability and certification, ensuring consistent quality for your manufacturing processes. **DISCLAIMER:** The information provided represents typical properties and characteristics based on standard specifications. Actual values may vary within acceptable specification ranges. For critical applications, material testing and validation are recommended. Consultation with materials engineering professionals is advised for specific application requirements. Proper heat treatment procedures must be followed to achieve desired final properties. -:- For detailed product information, please contact sales. -: AISI 4620 Steel, annealed, 25 mm round Specification Dimensions Size： Diameter 20-1000 mm Length <4077 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 4620 Steel, annealed, 25 mm round Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 4620 Steel Foil, annealed, 25 mm round -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 4620 Steel Foil, annealed, 25 mm round -:- For detailed product information, please contact sales. -:

Packing of AISI 4620 Steel Foil/Strip, annealed, 25 mm 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 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 548 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