AISI 4419 Steel, normalized

AISI 4419 Steel, normalized at 955°C (1750°F), 14 mm (0.55 in.) round Product Information -:- For detailed product information, please contact sales. -: AISI 4419 Steel, normalized at 955°C (1750°F), 14 mm (0.55 in.) round Synonyms -:- For detailed product information, please contact sales. -:

AISI 4419 Steel, normalized at 955°C (1750°F), 14 mm (0.55 in.) round Product Information -:- For detailed product information, please contact sales. -: # **Product Technical Data Sheet: AISI 4419 Normalized Steel Round Bar** **Product Designation:** AISI 4419 / SAE 4419 Normalized Steel **Condition:** Normalized at 955°C (1750°F), Air Cooled **Form & Size:** Round Bar, 14 mm (0.55 inch) Diameter --- ## **1. Overview** AISI 4419 is a **nickel-modified chromium-molybdenum low-alloy steel** characterized by its enhanced toughness and hardenability compared to standard 4100 series grades. The **normalizing heat treatment** at an elevated temperature of 955°C (1750°F) followed by controlled air cooling produces a refined, uniform ferrite-pearlite microstructure that optimizes mechanical properties for subsequent operations. The 14mm diameter represents an ideal **test and production size** that allows for rapid and uniform cooling, ensuring consistent properties throughout the cross-section. This normalized condition provides an excellent balance of strength, ductility, and machinability, serving as an optimal starting condition for components destined for carburizing, through-hardening, or direct use in normalized state for demanding applications. ## **2. Chemical Composition (Weight %)** *Composition per standard specifications for AISI 4419.* | Element | Content (%) | Metallurgical Function in Normalized Condition | |---------|-------------|----------------------------------------------| | **Carbon (C)** | 0.18 - 0.23 | Provides strength through pearlite formation and base hardenability | | **Manganese (Mn)** | 0.45 - 0.65 | Enhances hardenability and solid solution strengthening in ferrite | | **Silicon (Si)** | 0.15 - 0.35 | Deoxidizer, solid solution strengthener in ferrite phase | | **Chromium (Cr)** | 0.40 - 0.60 | Improves hardenability, refines pearlite structure during air cooling | | **Nickel (Ni)** | 0.20 - 0.40 | **Key differentiator:** Enhances toughness, refines ferrite grain, improves impact resistance | | **Molybdenum (Mo)** | 0.20 - 0.30 | Provides hardenability, refines pearlite lamellae, prevents excessive ferrite formation | | **Phosphorus (P)** | ≤ 0.035 | Impurity element (strictly controlled) | | **Sulfur (S)** | ≤ 0.040 | Improves machinability via MnS inclusions | | **Iron (Fe)** | Balance | Matrix element | **Normalizing-Specific Chemistry Benefits:** - **Nickel Content:** Promotes fine, equiaxed ferrite grain formation during air cooling - **Molybdenum Level:** Suppresses ferrite nucleation, promoting finer pearlite interlamellar spacing - **Carbon-Manganese Balance:** Optimized for complete pearlitic transformation in 14mm section during air cooling ## **3. Typical Physical Properties (Normalized Condition)** | Property | Value | Unit | Notes for 14mm Section | |----------|-------|------|-------------------------| | **Density** | 7.85 | g/cm³ | Uniform throughout 14mm diameter | | **Melting Range** | 1420 - 1470 | °C | Solidus to liquidus temperature | | **Modulus of Elasticity** | 200 - 205 | GPa | 29.0 - 29.7 × 10⁶ psi | | **Shear Modulus** | 78 - 80 | GPa | 11.3 - 11.6 × 10⁶ psi | | **Poisson's Ratio** | 0.29 - 0.30 | - | - | | **Thermal Conductivity** | 42.5 | W/m·K | At 100°C (212°F) | | **Specific Heat Capacity** | 475 | J/kg·K | At 20°C (68°F) | | **Coefficient of Thermal Expansion** | 11.8 × 10⁻⁶ | /°C | 20-100°C range | | **Electrical Resistivity** | 0.22 - 0.24 | μΩ·m | At 20°C (68°F) | | **Magnetic Properties** | Ferromagnetic | - | Curie temperature ~770°C | ## **4. Mechanical Properties (Normalized, 14mm Round)** | Property | Value Range | Typical Value | Test Standard | Notes | |----------|-------------|---------------|---------------|-------| | **Tensile Strength** | 620 - 720 MPa | 670 MPa | ASTM E8/E8M | 90 - 104 ksi | | **Yield Strength (0.2% offset)** | 380 - 480 MPa | 430 MPa | ASTM E8/E8M | 55 - 70 ksi | | **Elongation (in 50mm)** | 22 - 28% | 25% | ASTM E8/E8M | Good ductility | | **Reduction of Area** | 55 - 65% | 60% | ASTM E8/E8M | Excellent formability | | **Hardness (Brinell)** | 180 - 220 HBW | 200 HBW | ASTM E10 | 187 - 235 HB (3000kg) | | **Hardness (Rockwell)** | 90 - 98 HRB | 94 HRB | ASTM E18 | Or 20-30 HRC equivalent | | **Impact Energy (Charpy V-Notch)** | 50 - 80 J | 65 J | ASTM E23 | At 20°C (68°F) | | **Fatigue Strength** | 310 - 350 MPa | 330 MPa | Rotating bending | 10⁷ cycles, R=-1 | | **Endurance Ratio** | 0.50 - 0.52 | 0.51 | Fatigue/UTS | - | ## **5. Normalizing Process at 955°C (1750°F)** ### **Process Details for 14mm Round:** 1. **Heating:** Controlled heating to **955°C (1750°F)** at 150-200°C/hour - *Note: Higher than typical normalizing temperatures for enhanced grain refinement* 2. **Soaking:** 20-30 minutes at temperature for complete austenitization 3. **Air Cooling:** Still air cooling on refractory racks - Cooling rate: ~25-35°C/minute at 700°C transformation range 4. **Transformation:** Complete austenite to fine pearlite + ferrite transformation ### **Microstructural Characteristics:** - **Primary Structure:** Fine pearlite (70-80%) in fine ferrite matrix (20-30%) - **Grain Size:** ASTM 8-10 (fine-grained due to elevated normalizing temperature) - **Prior Austenite Grain Size:** ASTM 7-9 - **Pearlite Interlamellar Spacing:** 0.2-0.3 μm (fine due to Ni and Mo effects) - **Ferrite Grain Size:** ASTM 9-11 (refined by Ni content) - **Microstructural Uniformity:** Excellent throughout 14mm section ## **6. Key Characteristics & Advantages** ### **Normalized State Advantages:** 1. **Enhanced Toughness:** Nickel content provides superior impact resistance over 4118/4120 grades 2. **Improved Strength-Ductility Balance:** Fine microstructure from 955°C normalizing 3. **Excellent Machinability:** Fine pearlite structure with good chip formation characteristics 4. **Superior Hardenability:** Ni and Mo provide excellent response to subsequent heat treatment 5. **Good Weldability:** With proper pre- and post-weld procedures ### **955°C Normalizing Specific Benefits:** - **Complete Austenitization:** Ensures all carbides dissolve for uniform microstructure - **Grain Refinement:** Higher temperature followed by air cooling produces fine grains - **Homogenization:** Reduces microsegregation from casting/forging - **Stress Relief:** Eliminates residual stresses from previous processing ## **7. Applications** ### **Direct Use in Normalized Condition:** - **High-Strength Fasteners:** Bolts, studs, and pins requiring good toughness - **Shafts and Axles:** For applications where normalized properties are adequate - **Structural Components:** Brackets, linkages, and supports requiring good strength-toughness balance - **Hydraulic Components:** Cylinder rods, pistons in normalized state ### **Intermediate Condition for Heat Treatment:** - **Carburizing Blanks:** Gears, cams, bearing races requiring tough core properties - **Through-Hardening Components:** Tool holders, wear plates, cutting edges - **Precision Components:** Requiring machining before final heat treatment - **Prototype Development:** Material testing and process development ### **Industry-Specific Applications:** | Industry | Typical Components | Why AISI 4419? | |----------|-------------------|----------------| | **Automotive** | Transmission shafts, gear blanks, steering components | Nickel provides better impact resistance for safety components | | **Aerospace** | Non-critical structural parts, landing gear components | Enhanced toughness for fatigue resistance | | **Oil & Gas** | Valve stems, drilling tool components | Good combination of strength and corrosion resistance | | **Heavy Equipment** | Pivot pins, linkage arms, hydraulic components | Withstands shock loading better than nickel-free grades | ## **8. International Standards & Equivalents** ### **Material Standards:** | Standard System | Designation | Equivalent/Specification | |----------------|-------------|-------------------------| | **AISI/SAE (USA)** | 4419 | SAE J404, SAE J412 | | **UNS (USA)** | G44190 | Unified Numbering System | | **ASTM (USA)** | A322 | Grade 4419 | | **ISO** | **ISO 683-11** | Type 20NiCrMo2-2 (20NiCrMo2) | | **DIN (Germany)** | 1.6523 | 20NiCrMo2 | | **EN (Europe)** | **EN 10084** | 20NiCrMo2-2 | | **JIS (Japan)** | SNCM220 | Similar nickel-chromium-molybdenum steel | | **GB (China)** | 20CrNiMo | Chinese standard equivalent | ### **Comparative Analysis with Similar Grades:** | Property | AISI 4118 | **AISI 4419** | AISI 4320 | |----------|-----------|---------------|-----------| | **Nickel Content** | 0% | **0.20-0.40%** | 1.65-2.00% | | **Molybdenum** | 0.08-0.15% | **0.20-0.30%** | 0.20-0.30% | | **Typical Normalized Hardness** | 170-210 HBW | **180-220 HBW** | 190-230 HBW | | **Charpy Impact (20°C)** | 40-60 J | **50-80 J** | 60-90 J | | **Relative Cost** | Base | **+10-20%** | +30-50% | ## **9. Quality Assurance & Testing** ### **Standard Testing Requirements:** 1. **Chemical Analysis:** Complete elemental analysis with trace elements 2. **Mechanical Testing:** Tensile and impact tests from representative samples 3. **Hardness Testing:** Multiple point hardness across diameter 4. **Microstructural Examination:** Grain size and structure evaluation 5. **Decarburization Check:** Maximum 0.15mm total depth for 14mm round ### **Special Considerations for 955°C Normalizing:** - **Temperature Uniformity Verification:** Essential due to elevated temperature - **Cooling Rate Monitoring:** To ensure consistent microstructure - **Grain Size Control:** Verification of fine grain structure - **Surface Condition:** Assessment of minimal scale formation ### **Dimensional Specifications (14mm Round):** | Parameter | Tolerance | Standard | |-----------|-----------|----------| | **Diameter** | 14.0 ± 0.2 mm | ISO h10 tolerance | | **Out-of-Roundness** | ≤ 0.1 mm | - | | **Straightness** | ≤ 1.0 mm per meter | ISO 2768-m | | **Surface Roughness** | Ra ≤ 3.2 μm | As-supplied | | **Length Tolerance** | +10/-0 mm | Standard cuts | ## **10. Processing Recommendations** ### **Machining Guidelines:** - **Cutting Speed:** 35-50 m/min (115-165 SFM) for turning - **Feed Rate:** 0.15-0.25 mm/rev (0.006-0.010 in/rev) - **Depth of Cut:** Up to 3mm for roughing, 0.5-1.0mm for finishing - **Tool Materials:** Carbide or coated carbide recommended - **Coolant:** Use for optimum tool life and surface finish ### **Subsequent Heat Treatment Options:** 1. **Carburizing:** 900-925°C with carbon potential 0.80-0.90% - *Benefit: Nickel provides excellent core toughness* 2. **Through-Hardening:** Austenitize at 830-860°C, oil quench - *Benefit: Good hardenability from Ni and Mo* 3. **Tempering Range:** 150-650°C depending on required properties 4. **Stress Relieving:** 550-600°C if required after machining ### **Welding Procedures:** - **Preheat Temperature:** 150-200°C (300-400°F) for 14mm thickness - **Interpass Temperature:** 250°C maximum - **Post-Weld Heat Treatment:** 590-620°C for 1 hour - **Filler Material:** Matching composition or AWS E9018-B3 type - **Welding Processes:** GTAW, GMAW, or SMAW with low-hydrogen electrodes ### **Economic Considerations:** - **Material Cost:** 10-20% premium over 4118 due to nickel content - **Processing Cost:** Similar to other low-alloy steels - **Value Proposition:** Justified for applications requiring improved toughness - **Total Cost of Ownership:** Often favorable due to reduced failure rates --- **Technical Summary:** AISI 4419 normalized at 955°C offers a superior balance of properties for demanding applications. The nickel addition (0.20-0.40%) provides measurable improvements in toughness and impact resistance, while the molybdenum content (0.20-0.30%) ensures good hardenability and microstructural refinement. The elevated normalizing temperature of 955°C produces an exceptionally fine and uniform microstructure in the 14mm section, providing excellent mechanical properties in the normalized state and optimal preparation for subsequent heat treatment. **Application Selection Guidelines:** 1. **Choose AISI 4419 normalized when:** - Improved toughness is required over standard 4100 series grades - Components will undergo demanding heat treatment - Reliability under impact or fatigue loading is critical - Cost increase over 4118 is justified by performance requirements 2. **Consider alternatives when:** - Maximum cost-effectiveness is paramount (consider 4118) - Extreme nickel content is needed for maximum toughness (consider 4320) - Through-hardening of very large sections is required (consider higher hardenability grades) **Technical Note on 955°C Normalizing:** The elevated normalizing temperature is specifically beneficial for AISI 4419 due to its nickel content. Nickel lowers the Ac₃ temperature, allowing complete austenitization at this temperature while preventing excessive grain growth. This results in finer ferrite grains upon cooling and improved overall properties compared to conventional normalizing temperatures. **Disclaimer:** This technical data sheet provides typical values for AISI 4419 normalized at 955°C. Actual properties may vary based on specific mill practices, cooling conditions, and material history. For critical applications, material certification and application-specific testing are recommended. The elevated normalizing temperature requires careful control to prevent excessive grain growth or surface deterioration. -:- For detailed product information, please contact sales. -: AISI 4419 Steel, normalized at 955°C (1750°F), 14 mm (0.55 in.) round Specification Dimensions Size： Diameter 20-1000 mm Length <5587 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 4419 Steel, normalized at 955°C (1750°F), 14 mm (0.55 in.) round Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 4419 Steel, normalized at 955°C (1750°F), 14 mm (0.55 in.) round -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 4419 Steel, normalized at 955°C (1750°F), 14 mm (0.55 in.) round -:- For detailed product information, please contact sales. -:

Packing of AISI 4419 Steel, normalized at 955°C (1750°F), 14 mm (0.55 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 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 2058 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