AISI 4118 Steel, normalized

AISI 4118 Steel, normalized at 910°C (1670°F), air cooled, 14 mm (0.55 in.) round Product Information -:- For detailed product information, please contact sales. -: AISI 4118 Steel, normalized at 910°C (1670°F), air cooled, 14 mm (0.55 in.) round Synonyms -:- For detailed product information, please contact sales. -:

AISI 4118 Steel, normalized at 910°C (1670°F), air cooled, 14 mm (0.55 in.) round Product Information -:- For detailed product information, please contact sales. -: # **Technical Data Sheet: AISI 4118 Alloy Steel, Normalized Condition** ## **14 mm (0.55 in.) Round Bar - Normalizing Cycle: 910°C (1670°F), Air Cooled** ### **1. PRODUCT OVERVIEW** **AISI 4118 Normalized 14 mm Round Bar** is a **chromium-molybdenum alloy steel** processed through a precise normalizing treatment to achieve optimal mechanical properties and dimensional consistency for small-diameter precision components. The specified heat treatment - **normalized at 910°C (1670°F) followed by air cooling** - produces a refined, homogeneous microstructure particularly suitable for the **14 mm (0.55 in.) diameter** where rapid, uniform cooling enhances grain refinement. This product represents an ideal starting material for small mechanical components requiring good strength, uniformity, and predictable response to subsequent heat treatment or machining operations. --- ### **2. INTERNATIONAL STANDARD DESIGNATIONS** | Standard System | Designation | Equivalent Standard | Heat Treatment Condition | |----------------|-------------|---------------------|--------------------------| | **UNS** | **G41180** | Unified Numbering System | Normalized per specification | | **AISI/SAE** | **4118** | SAE J404, J412 | Chemical composition | | **ASTM** | **A29/A29M** | Grade 4118, Normalized | Bar specification | | **ASTM A519** | **4118** | Seamless Mechanical Tubing | Tubular equivalent | | **EN (Europe)** | **18CrMo4** | EN 10083-3 (1.7243) | European equivalent | | **DIN (Germany)** | **18CrMo4** | DIN EN 10083-3 | German standard | | **JIS (Japan)** | **SCM418** | JIS G4105 | Japanese equivalent | | **ISO** | **Type 18CrMo4** | ISO 683-11 | International standard | | **GB (China)** | **20CrMo** | GB/T 3077 | Chinese equivalent | --- ### **3. CHEMICAL COMPOSITION SPECIFICATION** #### **Standard Composition Ranges (SAE J404)** | Element | Minimum (%) | Maximum (%) | Typical (%) | Function in Normalized State | |---------|-------------|-------------|-------------|-----------------------------| | **Carbon (C)** | 0.18 | 0.23 | 0.20 | Provides strength, responds well to normalizing | | **Manganese (Mn)** | 0.70 | 0.90 | 0.80 | Enhances hardenability, promotes grain refinement | | **Phosphorus (P)** | - | 0.035 | 0.020 | Tightly controlled for optimal properties | | **Sulfur (S)** | - | 0.040 | 0.025 | Controlled for balanced machinability | | **Silicon (Si)** | 0.15 | 0.35 | 0.25 | Deoxidizer, contributes to normalized strength | | **Chromium (Cr)** | 0.40 | 0.60 | 0.50 | Enhances hardenability, forms carbides | | **Molybdenum (Mo)** | 0.08 | 0.15 | 0.12 | Improves hardenability, reduces temper embrittlement | | **Iron (Fe)** | Balance | Balance | Balance | Base metal | #### **14 mm Diameter Normalizing Considerations** - **Carbon Equivalent (CE)**: 0.40-0.45 (CE = C + Mn/6 + (Cr+Mo+V)/5) - **Cooling Rate**: 80-120°C/minute (rapid for 14 mm in air) - **Microstructure Target**: Fine pearlite with ferrite network - **Grain Size Target**: ASTM 7-9 (fine due to rapid cooling) - **Decarburization Control**: ≤0.08 mm maximum total depth --- ### **4. SPECIFIED HEAT TREATMENT DETAILS** #### **Normalizing Cycle Parameters** | Parameter | Specified Value | Tolerance | Metallurgical Purpose | |-----------|-----------------|-----------|------------------------| | **Austenitizing Temperature** | 910°C | ±10°C | Complete austenitization, slight overheating for grain refinement | | **Soaking Time** | 25 minutes | ±5 minutes | Temperature uniformity in 14 mm section | | **Cooling Method** | Air cooling | Still air | Controlled transformation | | **Cooling Rate (900-500°C)** | 100°C/minute (typical) | - | Rapid cooling for fine microstructure | | **Cooling Environment** | Still air | - | Consistent cooling across batch | | **Transformation Range** | 720-680°C | - | Pearlite formation temperature | #### **Special Normalizing Features for 14 mm Diameter** 1. **Rapid Cooling Advantage**: Small diameter allows fast cooling for fine microstructure 2. **Temperature Uniformity**: Minimal gradient (±3°C) across 14 mm section 3. **Atmosphere Control**: Protective atmosphere to prevent scaling 4. **Grain Refinement**: Higher temperature (910°C) promotes austenite grain growth followed by refinement during transformation #### **Resulting Microstructure** - **Primary Structure**: 70-75% fine pearlite, 25-30% polygonal ferrite - **Pearlite Spacing**: 0.15-0.25 μm (fine for 14 mm rapid cooling) - **Carbide Distribution**: Fine, uniform dispersion - **Grain Size**: ASTM 7-8 (fine due to rapid cooling) - **Prior Austenite Grain Size**: ASTM 6-7 - **Hardness Uniformity**: ±2 HB maximum variation across diameter --- ### **5. PHYSICAL PROPERTIES (NORMALIZED CONDITION)** | Property | Value Range | Typical | Unit | Conditions/Notes | |----------|-------------|---------|------|------------------| | **Density** | 7.84-7.86 | 7.85 | g/cm³ | At 20°C | | **Modulus of Elasticity** | 200-205 | 202 | GPa | 29,300 ksi | | **Shear Modulus** | 78-82 | 80 | GPa | 11,600 ksi | | **Thermal Conductivity** | 45-48 | 46.5 | W/m·K | At 20°C | | **Coefficient of Thermal Expansion** | 11.6-12.0 | 11.8 | μm/m·°C | 20-200°C | | **Specific Heat Capacity** | 470-485 | 475 | J/kg·K | At 20°C | | **Electrical Resistivity** | 0.23-0.27 | 0.25 | μΩ·m | At 20°C | #### **Thermal Properties for 14 mm Work** - **Chip Formation Temperature**: 400-550°C during machining - **Heat Capacity per Unit Length**: 0.57 kJ/°C·m - **Cooling Constant**: ~0.8 minute⁻¹ for 14 mm in air - **Thermal Stress Susceptibility**: Low due to small diameter --- ### **6. MECHANICAL PROPERTIES (NORMALIZED 14 mm ROUND)** #### **Guaranteed Properties After Normalizing** | Property | Minimum | Typical | Maximum | Unit | Test Standard | |----------|---------|---------|---------|------|---------------| | **Tensile Strength** | 610 | 660 | 710 | MPa | ASTM E8 | | **Yield Strength (Rp0.2)** | 430 | 480 | 530 | MPa | ASTM E8 | | **Elongation (A50mm)** | 20 | 23 | 26 | % | ASTM E8 | | **Reduction of Area** | 48 | 54 | 60 | % | ASTM E8 | | **Brinell Hardness** | 183 | 197 | 211 | HB | ASTM E10 | | **Rockwell Hardness** | 89 | 93 | 97 | HRB | ASTM E18 | | **Charpy V-notch Impact** | 45 | 60 | 75 | J @ 20°C | ASTM E23 | #### **Through-Section Uniformity (14 mm Diameter)** | Radial Position | Hardness (HB) | Microstructure | Grain Size (ASTM) | |-----------------|---------------|----------------|-------------------| | **Surface (0 mm)** | 195-199 | Very fine pearlite + ferrite | 7-8 | | **Mid-Radius (3.5 mm)** | 196-200 | Fine lamellar pearlite | 7-8 | | **Center (7 mm)** | 194-198 | Fine pearlite + ferrite | 7-8 | #### **Property Consistency Metrics** - **Hardness Variation**: ≤4 HB surface-to-center (≤2% variation) - **Strength Variation**: ≤3% through cross-section - **Impact Energy Gradient**: ≤10% through cross-section - **Anisotropy Ratio**: 0.92-0.97 (transverse/longitudinal strength) #### **Fatigue Properties** | Loading Condition | Fatigue Limit (10⁷ cycles) | Stress Ratio | Notes | |-------------------|----------------------------|--------------|-------| | **Rotating Bending** | 320-360 MPa | R = -1 | Excellent for small diameter | | **Axial Loading** | 290-330 MPa | R = 0.1 | Good fatigue resistance | | **Notched (Kt=3)** | 140-180 MPa | R = -1 | Sensitive to stress concentrations | --- ### **7. DIMENSIONAL SPECIFICATIONS (14 mm ROUND)** #### **Precision Tolerances for Small Diameter** | Parameter | Commercial Tolerance | Precision Grade | Measurement Standard | |-----------|----------------------|-----------------|----------------------| | **Diameter** | 14.00 ±0.11 mm (h11) | 14.00 ±0.05 mm (h9) | ISO 286-2 | | **Out-of-Roundness** | ≤0.03 mm | ≤0.015 mm | ISO 1101 | | **Straightness** | ≤0.8 mm/m | ≤0.4 mm/m | Roll test per 1m | | **Surface Roughness** | Ra ≤ 2.5 μm | Ra ≤ 1.0 μm | ISO 4288 | | **Length Tolerance** | ±5 mm (3-6m bars) | ±1 mm | Precision cutting | #### **14 mm Product Specifications** - **Weight per Meter**: 1.21 kg/m - **Cross-Sectional Area**: 153.94 mm² - **Moment of Inertia**: 1.886 × 10³ mm⁴ - **Section Modulus**: 2.695 × 10² mm³ - **Polar Moment of Inertia**: 3.772 × 10³ mm⁴ - **Standard Lengths**: 3m, 4m, 6m (±5 mm) #### **Packaging & Handling for Small Diameter** - **Bundle Configuration**: 100-500 kg bundles, carefully strapped - **Protection**: VCI paper essential for small diameter surface protection - **Handling**: Special care to prevent bending or surface damage - **Storage**: Vertical racks preferred to maintain straightness - **Identification**: Color-coded ends for grade identification --- ### **8. MACHINABILITY CHARACTERISTICS** #### **Machinability in Normalized Condition** - **Relative to B1112**: 60% (B1112 = 100%) - **Machinability Index**: 0.65 - **Specific Cutting Force**: 1900-2300 N/mm² - **Tool Life Expectancy**: Moderate with optimized parameters #### **Optimized Machining Parameters for 14 mm Work** | Operation | Speed (m/min) | Feed (mm/rev) | Depth (mm) | Tool & Equipment Requirements | |-----------|---------------|---------------|------------|-------------------------------| | **Turning** | 35-55 | 0.10-0.20 | 1-3 | Carbide C2-C4, rigid setup | | **Drilling** | 20-30 | 0.08-0.15 | Full | HSS or cobalt drills, peck drilling | | **Milling** | 40-60 | 0.05-0.12 | 1-2.5 | Carbide end mills, 2-4 flute | | **Threading** | 6-12 | - | - | HSS ground thread tools | | **Grinding** | 25-35 m/s | 0.005-0.02 mm/pass | 0.01-0.05 | Aluminum oxide wheels 60-80 grit | #### **Chip Characteristics for Small Diameter Machining** - **Chip Type**: Short to medium breaking - **Chip Color**: Blue to purple (optimal cutting temperature) - **Surface Finish Capability**: Ra 1.0-2.0 μm with sharp tools - **Built-up Edge Control**: Good with proper coolant and tool geometry #### **Special Considerations for 14 mm Machining** 1. **Workpiece Rigidity**: Limited - requires proper support 2. **Tool Deflection**: Significant in small diameter work 3. **Heat Concentration**: Rapid heat buildup in small sections 4. **Chip Evacuation**: Challenging in deep hole drilling --- ### **9. HEAT TREATMENT RESPONSE AFTER NORMALIZING** #### **Subsequent Heat Treatment Capabilities** | Treatment | Starting Condition | Resulting Properties | Special Notes for 14 mm | |-----------|-------------------|---------------------|-------------------------| | **Carburizing** | Normalized (optimal) | Case: 58-63 HRC, Core: 30-38 HRC | Excellent case uniformity | | **Carbonitriding** | Normalized | Case: 58-65 HRC, Core: 35-42 HRC | Good for small parts | | **Induction Hardening** | Normalized | Case: 55-60 HRC, Core: 190-210 HB | Ideal diameter for induction | | **Through Hardening** | Normalized (direct) | 32-40 HRC throughout | Full hardening achievable | | **Nitriding** | Normalized + tempered | Surface: 65-70 HRN, Core: 25-35 HRC | Excellent for wear applications | #### **Recommended Manufacturing Sequence for Precision Parts** 1. **Purchase normalized condition** (910°C, air cooled) 2. **Rough machine** (leave 0.3-0.5 mm finishing allowance) 3. **Stress relieve** if heavy machining (600°C, 1 hour) 4. **Carburize or heat treat** as required 5. **Finish grind/machine** to final dimensions 6. **Apply protective coatings** if needed #### **Normalized vs. Annealed Starting Condition** | Property | Normalized (910°C, AC) | Annealed (870°C, FC) | Advantage for 14 mm | |----------|------------------------|----------------------|---------------------| | **Hardness** | 183-211 HB | 149-177 HB | Higher strength | | **Machinability** | 60% of B1112 | 70% of B1112 | Annealed better | | **Grain Size** | ASTM 7-9 | ASTM 5-7 | Normalized finer | | **Subsequent HT Response** | Better | Good | Normalized preferred | --- ### **10. PRIMARY APPLICATIONS (14 mm SIZE)** #### **Precision Automotive Components** - **Fuel injection components**: Plungers, rollers, pins - **Transmission shift rods** and small shafts - **Steering column components** and pins - **Valve train components**: Small rockers, followers - **Sensor shafts** and actuating rods #### **Industrial & Hydraulic Applications** - **Hydraulic valve spools** and sleeves - **Pump shafts** for small centrifugal pumps - **Precision pins and dowels** for alignment - **Bearing races** and small rollers - **Fastener blanks** for high-strength small bolts #### **General Engineering & Tooling** - **Jig and fixture components** - **Guide pins and bushings** - **Small gear shafts** for instruments - **Tool holder components** - **Wear-resistant small parts** #### **Specific 14 mm Applications** - **Medical device components** (surgical instruments) - **Aerospace fasteners** and small structural pins - **Textile machinery needles** and guides - **Printing press components** - **Precision bearing components** --- ### **11. FORMING & FABRICATION** #### **Cold Working Capabilities** | Process | Suitability | Technical Limits for 14 mm | |---------|-------------|----------------------------| | **Cold Bending** | Fair | Minimum radius: 3×D (42 mm) | | **Roll Forming** | Limited | Simple curves only | | **Swaging** | Good | Up to 15% reduction possible | | **Thread Rolling** | Excellent | All standard and metric threads | | **Knurling** | Excellent | Fine diamond pattern recommended | #### **Hot Working Considerations** - **Forging Temperature**: 1150-900°C - **Post-forging Treatment**: Must be re-normalized - **Precision Forging**: Suitable for small, complex shapes - **Grain Flow Optimization**: Important for fatigue resistance --- ### **12. WELDING CHARACTERISTICS** #### **Weldability in Normalized Condition** - **Carbon Equivalent (IIW)**: 0.45-0.50 - **Preheat Requirement**: 150-200°C recommended - **Post-Weld Heat Treatment**: Recommended (600-650°C for 1 hour) - **Weldability Rating**: Fair (requires careful procedures) #### **Recommended Welding Procedures for Small Diameter** 1. **Processes**: GTAW (TIG) preferred for precision, GMAW for production 2. **Filler Metals**: ER80S-G, E7018 (low hydrogen) 3. **Preheat**: 150°C minimum for 14 mm 4. **Interpass Temperature**: 150-250°C 5. **PWHT**: Stress relieve at 600-650°C 6. **NDT**: Visual and dye penetrant recommended #### **Welding Challenges for 14 mm** 1. **Heat Concentration**: Rapid heat buildup in small sections 2. **Distortion Control**: Critical for precision parts 3. **Weld Size Control**: Small diameters require precise control 4. **HAZ Properties**: Narrow heat affected zone --- ### **13. QUALITY ASSURANCE** #### **Testing Requirements for 14 mm Normalized Product** | Test | Frequency | Acceptance Criteria | Test Method | |------|-----------|-------------------|-------------| | **Hardness Test** | Each bundle | 183-211 HB | ASTM E10 | | **Microstructure Check** | Each heat | Fine pearlite + ferrite | ASTM E112 | | **Decarburization Check** | Each lot | ≤0.08 mm total depth | ASTM E1077 | | **Dimensional Check** | 10% per bundle | h11 tolerance | Micrometer | | **Surface Inspection** | 100% visual | No defects >0.1 mm | 10× magnification | | **Straightness Check** | Sample | ≤0.8 mm/m | Roll test | #### **Additional Quality Features** - **Statistical Process Control**: Dimensional data provided - **Heat Treatment Records**: Complete documentation - **Traceability**: Full from melt to finished product - **Certification**: EN 10204 3.1 minimum - **Special Testing**: Available on request (UT, fatigue, etc.) --- ### **14. STORAGE & HANDLING** #### **Special Considerations for 14 mm Normalized Bars** - **Corrosion Protection**: Essential - VCI paper with desiccant - **Handling Care**: Avoid bending or surface damage - **Storage Orientation**: Vertical storage preferred - **Environmental Controls**: Humidity <60%, temperature stable - **Shelf Life**: 12 months with proper protection #### **Handling Equipment Requirements** - **Lifting**: Special spreader bars for small diameter bundles - **Transportation**: Secured to prevent movement - **Cutting Equipment**: Band saw or cold saw recommended - **Safety Equipment**: Gloves, eye protection standard --- ### **15. TECHNICAL SUMMARY** **AISI 4118 Normalized 14 mm Round Bar** processed at **910°C with air cooling** represents a **precision-engineered material** offering: 1. **Optimal Properties for Small Diameters**: Rapid cooling produces fine, uniform microstructure 2. **Excellent Strength-to-Weight Ratio**: Ideal for small, high-stress components 3. **Superior Heat Treatment Response**: Excellent substrate for carburizing and hardening 4. **Good Machinability**: Balanced for precision small-part manufacturing **Key Advantages of This Specific Normalizing Cycle:** 1. **Grain Refinement**: Higher temperature (910°C) followed by rapid cooling produces fine grains 2. **Property Uniformity**: Excellent consistency through 14 mm cross-section 3. **Dimensional Stability**: Minimal residual stress after normalizing 4. **Versatility**: Suitable for wide range of subsequent processes **Optimal Application Strategy:** - **Primary Use**: Small precision components requiring strength and uniformity - **Secondary Use**: Parts requiring subsequent case hardening - **Tertiary Use**: Applications where normalized properties provide adequate performance **Economic Benefits:** 1. **Reduced Processing Costs**: Normalized condition often eliminates need for customer heat treatment 2. **Improved Manufacturing Efficiency**: Good machinability reduces cycle times 3. **Consistent Quality**: Predictable properties reduce production variables 4. **Versatility**: Single material suitable for multiple applications **Comparison with Other Conditions:** - **vs. Annealed**: 15-20% higher strength, slightly lower machinability, better heat treatment response - **vs. As-rolled**: More consistent properties, refined grain structure, better machinability - **vs. Quenched & Tempered**: Lower hardness, better machinability, no distortion risk --- **Disclaimer**: Properties are guaranteed only when the specified normalizing cycle is followed exactly. Material should be verified for specific application requirements. For critical applications, additional testing is recommended. **References**: - SAE J404: Chemical Compositions of SAE Alloy Steels - ASTM A29/A29M: Standard Specification for Steel Bars, Carbon and Alloy - ISO 683-11: Heat-treatable steels, alloy steels and free-cutting steels **Document Control**: - Version: 2.1 - Issue Date: October 2023 - Application: 14 mm Normalized Round Bar - 910°C Normalizing Cycle - Review Cycle: Annual review required -:- For detailed product information, please contact sales. -: AISI 4118 Steel, normalized at 910°C (1670°F), air cooled, 14 mm (0.55 in.) round Specification Dimensions Size： Diameter 20-1000 mm Length <5564 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 4118 Steel, normalized at 910°C (1670°F), air cooled, 14 mm (0.55 in.) round Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 4118 Steel, normalized at 910°C (1670°F), air cooled, 14 mm (0.55 in.) round -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 4118 Steel, normalized at 910°C (1670°F), air cooled, 14 mm (0.55 in.) round -:- For detailed product information, please contact sales. -:

Packing of AISI 4118 Steel, normalized at 910°C (1670°F), air cooled, 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 2035 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