AISI 4820 Steel, normalized

AISI 4820 Steel, normalized 860°C (1580°F) Product Information -:- For detailed product information, please contact sales. -: AISI 4820 Steel, normalized 860°C (1580°F) Synonyms -:- For detailed product information, please contact sales. -:

AISI 4820 Steel, normalized 860°C (1580°F) Product Information -:- For detailed product information, please contact sales. -: # Technical Data Sheet: AISI 4820 Steel – Normalized at 860°C (1580°F) ## 1. Product Overview **AISI 4820** steel in the **normalized at 860°C (1580°F) condition** is a high-nickel alloy steel supplied in a normalized state optimized for **intermediate processing and property enhancement**. This normalization treatment at 860°C transforms the microstructure into a fine, uniform ferrite-pearlite structure while relieving internal stresses and refining the grain size. As part of the nickel-molybdenum carburizing steel family, AISI 4820 possesses exceptional potential for developing outstanding core toughness and wear resistance after final case hardening. The 860°C normalization provides improved strength and homogeneity compared to annealed conditions, making it suitable for components requiring intermediate strength before final heat treatment or for applications where normalized properties are sufficient. ## 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:** Carburizing Steels for Anti-Friction Bearings * **Heat Treatment 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 * **JIS:** SNCM220 * **GB:** 20NiCrMo (China) ## 3. Chemical Composition (SAE J404 Standard) | Element | Content Range (%) | Metallurgical Function | |---------|-------------------|------------------------| | **Carbon (C)** | 0.18–0.23 | Provides base hardenability; balanced for good core toughness in carburized state | | **Manganese (Mn)** | 0.50–0.70 | Enhances hardenability, promotes pearlite formation | | **Phosphorus (P)** | ≤0.035 | Residual element | | **Sulfur (S)** | ≤0.040 | Residual element | | **Silicon (Si)** | 0.15–0.35 | Deoxidizer, solid solution strengthening | | **Nickel (Ni)** | 3.25–3.75 | **Primary alloying element:** Exceptional toughness enhancement, improves hardenability | | **Chromium (Cr)** | — | Not specified (≤0.20% residual typical) | | **Molybdenum (Mo)** | 0.20–0.30 | Grain refinement, hardenability improvement, temper embrittlement resistance | ## 4. Normalizing Process & Metallurgical Effects ### 4.1 860°C (1580°F) Normalizing Cycle: - **Heating Rate:** Moderate (150–250°C/hour) - **Soaking Temperature:** 860°C ± 15°C (1580°F ± 25°F) - **Soaking Time:** 30–60 minutes per inch of thickness - **Cooling Method:** Still air cooling in uniform environment - **Atmosphere:** Protective or air (with allowance for slight scaling) ### 4.2 Microstructural Transformation: - **Phase Transformation:** Complete austenitization followed by air-cool transformation - **Resulting Structure:** Fine, uniform pearlite in ferrite matrix - **Grain Size:** ASTM 7–9 (finer than annealed condition) - **Carbide Morphology:** Fine, well-dispersed cementite lamellae - **Homogeneity:** Excellent throughout cross-section ## 5. Mechanical & Physical Properties (After Normalizing) ### 5.1 Mechanical Properties: | Property | Typical Value | Test Standard | Notes | |----------|---------------|---------------|-------| | **Hardness** | 187–229 HB (91–99 HRB) | ASTM E10/E18 | Higher than annealed condition | | **Tensile Strength** | 620–760 MPa (90–110 ksi) | ASTM E8 | 20–30% higher than annealed | | **Yield Strength (0.2%)** | 380–480 MPa (55–70 ksi) | ASTM E8 | Improved load-bearing capability | | **Elongation** | 22–28% in 50 mm | ASTM E8 | Good ductility for normalized state | | **Reduction of Area** | 50–60% | ASTM E8 | Maintains good formability | | **Impact Toughness (CVN)** | 50–70 J (37–52 ft-lb) @ 20°C | ASTM E23 | Excellent due to nickel content | ### 5.2 Physical Properties: - **Density:** 7.85 g/cm³ - **Thermal Conductivity:** 43.5 W/m·K @ 100°C - **Specific Heat:** 475 J/kg·K @ 100°C - **Coefficient of Thermal Expansion:** 11.8 × 10⁻⁶/°C (20–200°C) - **Modulus of Elasticity:** 203 GPa (29.5 × 10⁶ psi) ## 6. Machinability & Processing Characteristics ### 6.1 Machinability: - **Machinability Rating:** 55–60% of 1212 steel standard - **Cutting Speed:** 25–40 m/min (80–130 ft/min) for turning - **Tool Requirements:** Carbide tools recommended; positive rake angles beneficial - **Chip Control:** Produces shorter chips than annealed condition - **Surface Finish:** 1.0–2.0 μm Ra achievable with proper techniques ### 6.2 Forming & Fabrication: - **Cold Forming:** Moderate capabilities; may require intermediate annealing for severe deformation - **Weldability:** Fair to good with proper precautions - **Preheat:** 150–200°C (300–400°F) recommended - **Post-Weld:** Stress relief at 595–650°C (1100–1200°F) - **Machining Sequence:** Normalizing often performed after rough machining to relieve stresses ## 7. Key Characteristics & Advantages 1. **Enhanced Strength:** Provides higher strength than annealed condition while maintaining good ductility 2. **Grain Refinement:** Produces finer, more uniform microstructure than annealing 3. **Stress Relief:** Eliminates residual stresses from previous hot working operations 4. **Homogeneous Structure:** Ensures consistent properties throughout cross-section 5. **Improved Response to Final HT:** Creates optimal microstructure for subsequent carburizing 6. **Cost-Effective Intermediate:** Often sufficient for non-critical components without final hardening ## 8. Subsequent Heat Treatment Response ### 8.1 As Intermediate Treatment: - **Ideal Condition** for components requiring additional machining after stress relief - **Provides Uniform Starting Point** for final case hardening processes - **Minimizes Distortion** during final heat treatment compared to as-rolled condition ### 8.2 Final Heat Treatment Potential: - **Carburizing:** Excellent response at 900–925°C (1650–1700°F) - **Hardening:** Austenitize at 800–830°C (1470–1525°F), oil quench - **Expected Core Hardness:** 35–42 HRC after quenching from carburizing temperature - **Tempering:** 150–230°C (300–450°F) for optimal properties ## 9. Typical Applications ### 9.1 Applications in Normalized Condition: - **Structural Components:** Where normalized properties provide sufficient strength - **Intermediate Manufacturing State:** For components undergoing further processing - **Non-Critical Parts:** Where case hardening is not required - **Prototype Development:** For testing form, fit, and function ### 9.2 Final Applications (After Additional Heat Treatment): - **Aerospace:** Critical transmission components, landing gear parts - **Heavy Machinery:** Large gears, shafts, and bearing components - **Power Transmission:** Wind turbine gears, industrial gearbox components - **Automotive:** High-performance drivetrain components - **Mining Equipment:** Crusher components, large bearing races ## 10. Quality Control & Testing ### 10.1 Standard Testing: - **Hardness Survey:** Multiple locations to ensure uniformity - **Microstructure:** Verification of normalized structure and grain size - **Tensile Testing:** For critical applications requiring property verification - **Surface Condition:** Check for excessive decarburization or scaling ### 10.2 Certification: - **Mill Test Certificate:** Chemical composition - **Heat Treatment Certificate:** Normalizing parameters - **Property Reports:** Mechanical test results when specified ## 11. Comparative Analysis | Property | 860°C Normalized | 815°C Annealed | As-Rolled/Hot-Finished | |----------|------------------|----------------|------------------------| | **Hardness (HB)** | 187–229 | 149–179 | 207–255 | | **Tensile Strength** | 620–760 MPa | 500–620 MPa | 690–850 MPa | | **Machinability** | Good | Excellent | Fair | | **Grain Size** | ASTM 7–9 | ASTM 5–7 | Variable | | **Dimensional Stability** | Very Good | Excellent | Fair | ## 12. Storage & Handling - **Storage:** Dry, covered storage preferred - **Corrosion Protection:** Light oil or VCI protection recommended - **Handling:** Standard steel handling practices - **Identification:** Clearly marked with grade, condition, and heat number ## 13. Technical Limitations 1. **Not for High-Wear Service:** Without subsequent case hardening 2. **Scale Formation:** Some surface scaling inevitable with air cooling 3. **Size Limitations:** Properties may vary in very thick sections 4. **Decarburization:** Possible if not protected during heating --- **Important Note:** This normalized condition represents an intermediate processing state for AISI 4820 steel. While providing improved mechanical properties over annealed conditions, it does not represent the final optimized state for most applications. For components requiring maximum wear resistance, fatigue strength, or impact resistance, subsequent case hardening (carburizing) and quenching treatments are necessary. The normalization at 860°C provides an excellent foundation for these final treatments, ensuring consistent results and minimizing distortion. *Properties are typical for sections up to 75 mm (3 inches) thickness. For larger sections or specific applications, consultation with a metallurgical engineer is recommended to determine appropriate normalizing parameters and expected properties.* -:- For detailed product information, please contact sales. -: AISI 4820 Steel, normalized 860°C (1580°F) Specification Dimensions Size： Diameter 20-1000 mm Length <5668 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, normalized 860°C (1580°F) Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 4820 Steel, normalized 860°C (1580°F) -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 4820 Steel, normalized 860°C (1580°F) -:- For detailed product information, please contact sales. -:

Packing of AISI 4820 Steel, normalized 860°C (1580°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 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 2139 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