AISI 4820 Steel Capillary,

AISI 4820 Steel Capillary, annealed 815°C (1500°F) Product Information -:- For detailed product information, please contact sales. -: AISI 4820 Steel Capillary, annealed 815°C (1500°F) Synonyms -:- For detailed product information, please contact sales. -:

AISI 4820 Steel, annealed 815°C (1500°F) Product Information -:- For detailed product information, please contact sales. -: # Technical Data Sheet: AISI 4820 Steel – Annealed at 815°C (1500°F) Condition ## 1. Product Overview **AISI 4820** steel in the **annealed at 815°C (1500°F) condition** is a nickel-molybdenum alloy steel supplied in a thermally processed state specifically optimized for **machinability and subsequent heat treatment preparation**. This annealing treatment at 815°C (1500°F) represents a **full annealing cycle** that produces a uniform, soft microstructure of ferrite and pearlite with minimized residual stresses. As a medium-carbon, nickel-rich alloy steel, AISI 4820 is primarily designed for **case hardening through carburizing**, where it develops exceptional core toughness combined with a wear-resistant surface. The 815°C anneal provides the ideal starting condition for precision machining operations prior to final heat treatment, ensuring dimensional stability and consistent material behavior during manufacturing. ## 2. Material Specifications & Standards * **UNS Designation:** G48200 * **AISI/SAE:** 4820 * **Primary Material Standards:** * **SAE J404:** Chemical Compositions of SAE Alloy Steels * **ASTM A322:** Standard Specification for Steel Bars, Alloy, Standard Grades * **ASTM A534:** Standard Specification for Carburizing Steels for Anti-Friction Bearings * **Annealing Reference Standards:** * **SAE J1268:** Heat Treatment of Steel * **AMS 2759/1:** Heat Treatment of Steel Parts, General Requirements * **International Equivalents:** * **EN/DIN:** 20NiCrMo2-2 / 1.6523 (Similar to 4620 series in Europe) * **JIS:** SNCM220 (Japanese classification) * **GB:** 20NiCrMo (China) ## 3. Chemical Composition (SAE J404 Standard) | Element | Content Range (%) | Metallurgical Function | |---------|-------------------|------------------------| | **Carbon (C)** | 0.18–0.23 | Provides base hardenability while maintaining good core toughness after carburizing | | **Manganese (Mn)** | 0.50–0.70 | Enhances hardenability and strength through solid solution strengthening | | **Phosphorus (P)** | ≤0.035 | Residual element, controlled to minimize detrimental effects | | **Sulfur (S)** | ≤0.040 | Residual element; may be specified with controlled additions for improved machinability | | **Silicon (Si)** | 0.15–0.35 | Deoxidizer during steelmaking; provides solid solution strengthening | | **Nickel (Ni)** | 3.25–3.75 | **Primary alloying element:** Dramatically improves core toughness, impact resistance, and hardenability | | **Chromium (Cr)** | — | Not a specified alloying element in standard 4820 (may be present as residual ≤0.20%) | | **Molybdenum (Mo)** | 0.20–0.30 | **Critical addition:** Refines grain structure, improves hardenability, reduces temper embrittlement susceptibility | ## 4. Annealing Process & Metallurgical Effects ### 4.1 815°C (1500°F) Annealing Cycle: - **Heating Rate:** Controlled heating to prevent thermal shock (typically 100–200°C/hour) - **Soaking Temperature:** 815°C ± 10°C (1500°F ± 20°F) - **Soaking Time:** 1–2 hours per inch of cross-section (minimum 2 hours) - **Cooling Rate:** Slow furnace cooling at 10–30°C/hour (20–50°F/hour) to approximately 550°C (1000°F), followed by air cooling - **Atmosphere:** Protective (endothermic gas or neutral) to prevent oxidation and decarburization ### 4.2 Resulting Microstructure: - **Primary Structure:** Coarse lamellar pearlite in a ferrite matrix - **Grain Size:** ASTM 5–7 (relatively coarse due to full annealing) - **Carbide Distribution:** Spheroidized or partially spheroidized carbides depending on cooling rate - **Hardness:** Uniform throughout cross-section ## 5. Mechanical & Physical Properties (After 815°C Anneal) ### 5.1 Mechanical Properties: | Property | Typical Value | Test Standard | Notes | |----------|---------------|---------------|-------| | **Hardness** | 149–179 HB (85–90 HRB) | ASTM E10/E18 | Ideal for machining operations | | **Tensile Strength** | 500–620 MPa (73–90 ksi) | ASTM E8 | Consistent throughout material | | **Yield Strength (0.2%)** | 275–380 MPa (40–55 ksi) | ASTM E8 | Low yield strength facilitates forming | | **Elongation** | 28–33% in 50 mm | ASTM E8 | Excellent ductility | | **Reduction of Area** | 55–65% | ASTM E8 | Indicates good formability | | **Modulus of Elasticity** | 200–205 GPa (29–30 × 10⁶ psi) | ASTM E111 | Typical for alloy steels | ### 5.2 Physical Properties: - **Density:** 7.85 g/cm³ (0.284 lb/in³) - **Thermal Conductivity:** 42.6 W/m·K at 100°C - **Specific Heat:** 460 J/kg·K at 100°C - **Coefficient of Thermal Expansion:** 11.5 × 10⁻⁶/°C (20–100°C) - **Magnetic Properties:** Ferromagnetic ## 6. Machinability & Formability ### 6.1 Machinability Characteristics: - **Machinability Rating:** 60–65% of 1212 steel standard - **Recommended Cutting Speeds:** 30–45 m/min (100–150 ft/min) for turning operations - **Tool Materials:** High-speed steel or carbide tools with positive rake angles - **Chip Formation:** Produces discontinuous chips with proper tool geometry - **Surface Finish:** Can achieve 0.8–1.6 μm (32–63 μin) Ra with proper techniques ### 6.2 Forming Characteristics: - **Cold Formability:** Good for moderate deformation operations - **Bend Radius:** Minimum bend radius approximately 1 × thickness for 90° bends - **Punchability:** Suitable for punching and blanking operations - **Recommendation:** Stress relief annealing may be required after severe cold working ## 7. Key Characteristics & Advantages 1. **Optimal Machining Condition:** The 815°C anneal produces the softest, most uniform structure for precision machining operations 2. **Dimensional Stability:** Minimized residual stresses reduce distortion during and after machining 3. **Consistent Material Behavior:** Uniform microstructure ensures predictable tool wear and consistent cutting forces 4. **Excellent Surface Finish:** Capable of producing fine surface finishes required for precision components 5. **Good Tool Life:** Balanced hardness and microstructure provide reasonable tool life during machining 6. **Preparation for Heat Treatment:** Provides ideal starting condition for subsequent carburizing and hardening processes ## 8. Subsequent Heat Treatment Response ### 8.1 Carburizing Response: - **Carburizing Temperature:** 900–925°C (1650–1700°F) - **Case Depth:** Capable of developing 0.5–2.5 mm effective case depth - **Surface Hardness:** 58–63 HRC after proper heat treatment - **Core Hardness:** 35–42 HRC after quenching and tempering ### 8.2 Hardening Characteristics: - **Austenitizing Temperature:** 800–830°C (1470–1525°F) for core hardening - **Quenching Medium:** Oil preferred for most applications - **Tempering Range:** 150–230°C (300–450°F) for optimal properties - **Distortion Characteristics:** Predictable and manageable with proper fixturing ## 9. Typical Applications ### 9.1 Primary Applications (After Final Heat Treatment): - **Aerospace Components:** - Aircraft landing gear parts - Helicopter transmission gears - Engine accessory drive components - **Heavy Equipment:** - Large gears for mining equipment - Heavy-duty axle shafts - Track system components - **Industrial Machinery:** - High-load gears and pinions - Critical bearing components - Large machinery shafts - **Automotive:** - High-performance transmission gears - Heavy-duty differential components - Specialty fasteners and studs ### 9.2 Manufacturing Sequence: 1. Receive material in 815°C annealed condition 2. Perform all rough and finish machining operations 3. Clean and prepare for heat treatment 4. Carburize and harden to final specifications 5. Perform final grinding/honing if required 6. Inspect and assemble ## 10. Quality Control & Testing ### 10.1 Standard Testing for Annealed Condition: - **Hardness Testing:** Multiple points to ensure uniformity - **Microstructure Examination:** Verification of proper annealing structure - **Dimensional Verification:** Compliance with size tolerances - **Surface Inspection:** Freedom from decarburization and defects ### 10.2 Certification Requirements: - **Mill Test Certificate:** Chemical composition and mechanical properties - **Heat Treatment Certificate:** Verification of annealing cycle parameters - **Traceability:** Heat number and processing history ## 11. Storage & Handling - **Storage Conditions:** Dry, temperature-controlled environment - **Protection:** VCI paper or protective coatings to prevent rust - **Handling:** Use appropriate lifting equipment to prevent damage - **Shelf Life:** Unlimited with proper corrosion protection - **Identification:** Clearly marked with grade, condition, and heat number ## 12. Technical Limitations & Considerations 1. **Not for Final Service:** This condition is for machining only, not for end use 2. **Decarburization Risk:** Prolonged exposure to high temperatures without protection can cause surface decarburization 3. **Size Limitations:** Properties may vary in very large cross-sections 4. **Subsequent Processing:** All machining must be completed before final heat treatment 5. **Cost Factor:** Higher material cost compared to standard carbon steels ## 13. Environmental & Safety - **Compliance:** RoHS and REACH compliant - **Recyclability:** 100% recyclable as alloy steel scrap - **Safety Precautions:** Standard steel handling procedures apply - **Disposal:** Should be recycled through authorized steel recyclers --- **Important Note:** This material in the 815°C annealed condition is supplied specifically for **machining and manufacturing operations prior to final heat treatment**. The properties listed represent the material in its annealed state only. Final service properties are achieved only after proper carburizing, hardening, and tempering processes. For critical applications, consultation with a metallurgical engineer is recommended to optimize both the annealing and final heat treatment processes for specific component requirements. *All values provided are typical and may vary based on specific manufacturing processes, section size, and annealing furnace characteristics. Actual properties should be verified through appropriate testing for critical applications.* -:- For detailed product information, please contact sales. -: AISI 4820 Steel, annealed 815°C (1500°F) Specification Dimensions Size： Diameter 20-1000 mm Length <5667 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 4820 Steel, annealed 815°C (1500°F) Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 4820 Steel Capillary, annealed 815°C (1500°F) -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 4820 Steel Capillary, annealed 815°C (1500°F) -:- For detailed product information, please contact sales. -:

Packing of AISI 4820 Steel Capillary, annealed 815°C (1500°F) -:- 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 Capillary 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 2138 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