AISI 4023 Steel,

AISI 4023 Steel, Product Information -:- For detailed product information, please contact sales. -: AISI 4023 Steel, Synonyms -:- For detailed product information, please contact sales. -:

AISI 4023 Steel, Product Information -:- For detailed product information, please contact sales. -: # **Product Introduction: AISI 4023 Steel** ## **Executive Summary** **AISI 4023** is a low-carbon molybdenum alloy steel engineered for **case-hardening applications** requiring improved performance over basic carbon steels. As part of the AISI 40xx series, it contains approximately **0.20-0.25% carbon and 0.20-0.30% molybdenum**, positioning it as a versatile, cost-effective material for components that benefit from a hard, wear-resistant surface combined with a moderately strong, ductile core. The molybdenum addition provides enhanced hardenability, better control of case depth, and improved grain structure stability during high-temperature carburizing processes. AISI 4023 is widely utilized in automotive, agricultural, and general industrial applications where reliable performance and manufacturing economy are paramount. --- ## **1. Chemical Composition** ### **Standard Composition Ranges** | Element | Content Range (% by weight) - **AISI 4023** | Primary Function | | :--- | :--- | :--- | | **Carbon (C)** | 0.20 - 0.25 | Provides moderate core strength; balanced for good machinability and effective case absorption | | **Molybdenum (Mo)** | 0.20 - 0.30 | Enhances hardenability, refines grain structure, improves temper resistance, reduces susceptibility to temper embrittlement | | **Manganese (Mn)** | 0.70 - 0.90 | Deoxidizer, improves hardenability, enhances response to carburizing | | **Silicon (Si)** | 0.15 - 0.35 | Deoxidizer, strengthens ferrite matrix | | **Phosphorus (P)** | 0.035 max | Impurity (controlled for ductility) | | **Sulfur (S)** | 0.040 max | Impurity (may be controlled for improved machinability) | | **Nickel (Ni)** | - | Not specified; trace amounts may be present | | **Chromium (Cr)** | - | Not specified; trace amounts may be present | | **Iron (Fe)** | Balance | Matrix element | ### **Key Metallurgical Features** - **Core Properties:** Higher carbon content than 4012 provides increased core strength while maintaining good ductility - **Hardenability Enhancement:** Molybdenum significantly improves through-hardening capability compared to plain carbon steels - **Grain Control:** Molybdenum inhibits austenite grain growth during high-temperature carburizing - **Processing Stability:** Consistent response to heat treatment across different production batches - **Economic Balance:** Provides performance improvements over 1020/1025 steels without nickel/chromium costs --- ## **2. Physical & Mechanical Properties** ### **A. Fundamental Physical Properties** | Property | Condition | Value/Range | Notes | | :--- | :--- | :--- | :--- | | **Density** | All conditions | 7.85 g/cm³ (0.284 lb/in³) | - | | **Melting Point** | - | ~1515°C (2760°F) | - | | **Elastic Modulus** | Annealed/Tempered | 200-205 GPa (29,000-29,700 ksi) | - | | **Shear Modulus** | - | 80-82 GPa (11,600-11,900 ksi) | - | | **Poisson's Ratio** | - | 0.29 | - | | **Thermal Conductivity** | 100°C | 45.0 W/m·K | - | | **Specific Heat Capacity** | 20°C | 475 J/kg·K | - | | **Thermal Expansion Coefficient** | 20-100°C | 11.9 × 10⁻⁶/°C | - | | **Electrical Resistivity** | 20°C | 0.22 μΩ·m | - | | **Magnetic Properties** | Below Curie temp | Ferromagnetic | - | ### **B. Mechanical Properties (Core - Before Case Hardening)** #### **1. Annealed/Normalized Condition (Machining State)** - **Hardness:** 149-179 HB (Brinell) - **Tensile Strength:** 485-620 MPa (70-90 ksi) - **Yield Strength (0.2% offset):** 345-485 MPa (50-70 ksi) - **Elongation:** 25-30% in 50mm - **Reduction of Area:** 60-70% - **Charpy V-Notch Impact:** 80-120 J (59-88 ft-lb) at room temperature - **Machinability Rating:** 65-70% of B1112 (Good) #### **2. Core Properties After Case Hardening & Tempering** *Typical heat treatment: Carburize to 0.6-1.5 mm case, quench, temper at 150-200°C* | Property | Typical Value Range | Notes | | :--- | :--- | :--- | | **Core Hardness** | 25-35 HRC | Stronger core than lower-carbon case-hardening steels | | **Core Tensile Strength** | 690-860 MPa (100-125 ksi) | - | | **Core Yield Strength** | 550-690 MPa (80-100 ksi) | - | | **Core Elongation** | 15-20% | Maintains good ductility | | **Case Hardness** | 58-63 HRC | After carburizing and quenching | | **Effective Case Depth** | 0.5-1.5 mm (0.020-0.060") | Standard industrial range | | **Surface Carbon Content** | 0.75-0.90% | Optimized for wear resistance | | **Charpy V-Notch Impact (Core)** | 50-80 J (37-59 ft-lb) | Good impact resistance | | **Bending Fatigue Strength** | 400-500 MPa (58-73 ksi) | At 10⁷ cycles with carburized case | #### **3. Through-Hardened Properties (Alternative Application)** *When used for direct quenching and tempering without carburizing* - **Hardness (as-quenched):** 40-45 HRC (oil quenched) - **Tensile Strength (Q&T @ 540°C):** 860-1030 MPa (125-150 ksi) - **Yield Strength:** 690-860 MPa (100-125 ksi) - **Applications:** Bolts, studs, and components requiring moderate strength ### **C. Special Properties** - **Hardenability:** Good for a lean alloy steel; suitable for sections up to 40-50mm (1.5-2.0") - **Fatigue Performance:** Good resistance to bending fatigue with carburized case - **Wear Resistance:** Excellent surface wear characteristics when case hardened - **Impact Resistance:** Good core toughness for shock loading applications - **Distortion Control:** Molybdenum helps minimize distortion during heat treatment --- ## **3. International Standards & Specifications** ### **Primary Governing Standards** | Standard/Organization | Designation | Title/Scope | | :--- | :--- | :--- | | **AISI/SAE** | 4023 | Standard grade designation | | **UNS** | G40230 | Unified Numbering System | | **ASTM** | A534 | Standard Specification for Carburizing Steels | | **ASTM** | A29/A29M | Standard Specification for Steel Bars, Carbon and Alloy, Hot-Wrought | | **SAE** | J404, J412 | Chemical compositions and hardenability | | **AMS** | - | Not commonly specified for aerospace | ### **International Equivalents & Cross-References** | Country/Region | Equivalent Designation | Standard | Notes | | :--- | :--- | :--- | :--- | | **ISO** | **- (See Note)** | ISO 683-11 | No direct equivalent; similar to C22E/1.1151 with Mo | | **European** | **- (See Note)** | EN 10084 | No direct equivalent; concept similar to 20MoCr4 | | **Germany** | **- (See Note)** | DIN 17210 | No direct equivalent; 25MoCr4 is similar but with Cr | | **Japan** | **- (See Note)** | JIS G4102 | No common direct equivalent | | **China** | **20Mo** | GB/T 3077 | Similar concept, not exact match | | **India** | **20Mo40** | IS 5517 | Similar molybdenum steel | | **Hardenability Variant** | **4023H** | SAE J1268 | Available with guaranteed hardenability bands | **Note:** AISI 4023 is primarily a North American grade. International procurement typically requires specification by chemical composition rather than grade name. The closest European conceptual equivalents would be lean-alloy case-hardening steels with approximately 0.2% C and 0.2% Mo. --- ## **4. Product Applications & Industries** ### **Available Product Forms** - **Bar Stock:** Hot-rolled rounds (10-150mm), squares, hexagons (most common) - **Wire Rod:** For cold heading of fasteners and components - **Cold-Finished Bars:** Turned, ground, polished for precision parts - **Forgings:** For specific component geometries - **Billets:** For further processing ### **Primary Industry Applications** #### **1. Automotive & Transportation** - **Transmission Components:** Gears, synchronizer hubs, shift forks - **Drivetrain Parts:** Differential side gears, spider gears, axle shafts (light-medium duty) - **Engine Components:** Camshafts, rocker arms, valve train parts - **Steering & Suspension:** Tie rod ends, ball studs, linkage components - **Fasteners:** High-strength bolts, studs, and special fasteners #### **2. Agricultural Equipment** - **Tractor Components:** Transmission gears, PTO shafts, implement drive parts - **Harvesting Equipment:** Combine gearbox components, drive chains - **Implement Parts:** Gearboxes, drive shafts, pivot pins - **Tillage Equipment:** Gears and shafts in seeders and planters #### **3. Industrial Machinery & Equipment** - **Gear Manufacturing:** Industrial gears for power transmission, speed reducers - **Power Transmission:** Sprockets, chain wheels, coupling components - **Material Handling:** Conveyor drive components, hoisting equipment gears - **Construction Equipment:** Light-duty gearbox components, drive parts - **Machine Tools:** Feed mechanism components, gear train parts #### **4. General Manufacturing** - **Fastener Industry:** Grade 5 and similar strength class fasteners - **Tooling:** Jigs, fixtures, and tool bodies requiring wear surfaces - **Consumer Products:** Durable hardware, appliance gears, power tool components - **Hydraulic Components:** Valve parts, pump components requiring wear resistance --- ## **5. Heat Treatment Technology** ### **Primary Case Hardening Processes** #### **1. Carburizing (Standard Process)** - **Temperature:** 900-930°C (1650-1705°F) - **Atmosphere:** Endothermic gas with natural gas or propane enrichment - **Case Depth:** Typically 0.5-1.5 mm (0.020-0.060") - **Surface Carbon:** 0.75-0.90% - **Quenching:** Oil quench from carburizing temperature or reheat to 800-830°C - **Tempering:** 150-200°C (300-390°F) for 1-2 hours #### **2. Carbonitriding (Alternative Process)** - **Temperature:** 815-870°C (1500-1600°F) - **Atmosphere:** Endothermic gas with ammonia (3-10%) - **Case Depth:** 0.1-0.8 mm (0.004-0.030") - **Advantages:** Faster processing, better dimensional control, improved wear resistance ### **Typical Heat Treatment Cycle** 1. **Pre-Cleaning:** Remove oils and contaminants 2. **Preheating:** 650-700°C (1200-1290°F) for large sections (optional) 3. **Carburizing:** At temperature for required time (approximately 4-8 hours for 1mm case) 4. **Diffusion:** Optional step to control carbon gradient 5. **Quenching:** Oil quench with moderate agitation 6. **Tempering:** 150-200°C for stress relief 7. **Finishing:** Grinding, shot peening, or other surface treatments as required ### **Special Considerations** - **Grain Growth:** Molybdenum helps control grain growth, but excessive time at high temperature should be avoided - **Distortion:** Moderate distortion expected; fixturing or press quenching may be used for critical dimensions - **Core Properties:** Higher carbon content provides stronger core than 4012, suitable for more heavily loaded components --- ## **6. Manufacturing & Fabrication Characteristics** ### **Machinability Assessment** - **Annealed Condition:** **65-70% of B1112** – Rated as **Good to Very Good** - **Case Hardened Condition:** Not machinable by conventional methods - **Recommended Practices:** - **Turning:** 75-110 m/min (250-360 SFM) with carbide inserts - **Drilling:** 20-30 m/min (65-100 SFM) with HSS drills - **Milling:** 70-100 m/min (230-330 SFM) with carbide cutters - **Threading/Tapping:** Good performance with standard practices - **Gear Cutting:** Suitable for hobbing, shaping, and shaving operations ### **Weldability Characteristics** **Rating: GOOD (with standard precautions)** #### **Welding Recommendations** 1. **Preheat:** 100-150°C (212-300°F) for sections over 25mm thickness 2. **Interpass Temperature:** 150-200°C (300-390°F) 3. **Post-Weld Heat Treatment:** Stress relief at 590-650°C (1100-1200°F) recommended for critical components 4. **Filler Metals:** Low-hydrogen electrodes (E7018) or equivalent wire 5. **Processes:** SMAW, GMAW, GTAW all suitable with proper technique 6. **Note:** Welding after case hardening will destroy case properties; weld in annealed condition only ### **Formability & Cold Working** - **Cold Formability:** **Good** in annealed condition - **Processes:** Cold heading, forging, bending, stamping - **Strain Hardening:** Moderate; intermediate annealing may be needed for severe deformation - **Springback:** Moderate; compensation in tool design may be required ### **Hot Working** - **Hot Working Temperature:** 1150-900°C (2100-1650°F) - **Forging:** Excellent forgeability with proper temperature control - **Cooling After Hot Work:** Normalizing recommended for optimal properties --- ## **7. Quality Assurance & Testing** ### **Standard Certification** - **Mill Test Certificate:** Includes heat chemistry, mechanical properties, and dimensional data - **Chemical Analysis:** Spectrographic analysis of key elements - **Hardness Testing:** Brinell or Rockwell testing of supplied material - **Microstructural Examination:** When specified for critical applications ### **Finished Part Testing** - **Case Depth Verification:** Microhardness traverse or metallographic examination - **Surface Hardness:** Rockwell C scale testing - **Core Hardness:** Rockwell testing of sectioned parts - **Non-Destructive Testing:** Magnetic particle or dye penetrant for surface defects - **Dimensional Inspection:** Critical for heat treated components --- ## **8. Design & Engineering Guidelines** ### **Advantages of AISI 4023** 1. **Balanced Performance:** Good combination of core strength and surface hardness 2. **Cost-Effective:** More economical than nickel-chromium alloyed steels 3. **Good Machinability:** Lower manufacturing costs before heat treatment 4. **Consistent Heat Treatment:** Reliable response to carburizing processes 5. **Versatile Applications:** Suitable for a wide range of industrial components ### **Design Considerations** - **Case Depth:** Typically 0.5-1.5mm; should not exceed 20% of section thickness - **Loading Conditions:** Suitable for medium-duty applications with bending and contact stresses - **Core Support:** Higher carbon content provides better support for hard case than 4012 - **Alternative Materials:** For heavier loads, consider 4118, 8620, or 4320 ### **Economic Considerations** - **Material Cost:** Moderate; more than plain carbon steels but less than nickel-alloyed grades - **Processing Cost:** Standard carburizing processes apply - **Tooling Cost:** Good machinability reduces tooling expenses - **Life Cycle Cost:** Good value for performance requirements --- ## **9. Comparative Analysis: Case-Hardening Steels** | Grade | C% | Alloying | Core Strength | Hardenability | Cost Ratio | Best Applications | | :--- | :--- | :--- | :--- | :--- | :--- | :--- | | **1020** | 0.18-0.23 | None | Low | Very Low | 1.0 | Light-duty, simple parts | | **4023** | 0.20-0.25 | **0.20-0.30 Mo** | **Medium** | **Good** | **1.3-1.5** | **General industrial components** | | **4118** | 0.18-0.23 | 0.40-0.60 Cr, 0.08-0.15 Mo | Medium-High | Very Good | 1.5-1.8 | Automotive gears, shafts | | **8620** | 0.18-0.23 | 0.40-0.70 Ni, 0.40-0.60 Cr, 0.15-0.25 Mo | High | Excellent | 1.8-2.2 | Critical gears, bearings | | **4320** | 0.17-0.22 | 1.65-2.00 Ni, 0.40-0.60 Cr, 0.20-0.30 Mo | Very High | Outstanding | 2.2-2.8 | High-performance components | --- ## **10. Technical Summary & Selection Guidelines** ### **Optimal Applications for AISI 4023** 1. **Automotive Components:** Transmission gears, differential parts, camshafts 2. **Agricultural Equipment:** Tractor transmission components, implement gears 3. **Industrial Gears:** Medium-duty power transmission gears 4. **Fasteners:** Grade 5 and similar strength class bolts and studs 5. **General Machinery:** Components requiring wear resistance with moderate loading ### **Selection Criteria** **Choose AISI 4023 when:** - Component requires case hardening with medium core strength - Cost constraints limit use of nickel-alloyed steels - Good machinability is important for manufacturing economy - Section sizes are moderate (up to 50mm) - Applications involve bending fatigue and surface wear **Consider Higher-Grade Alternatives when:** - Maximum core toughness is critical (choose nickel-alloyed grades) - Very deep case depths (>1.5mm) are required - Section sizes exceed 75mm diameter - Application involves extreme shock loading - Corrosion resistance is needed without coatings ### **Processing Recommendations** 1. **Machining:** Perform in annealed condition for best results 2. **Heat Treatment:** Carburize at 900-930°C, oil quench, temper at 150-200°C 3. **Finishing:** Grind critical surfaces after heat treatment 4. **Quality Control:** Verify case depth and hardness for critical applications --- ## **Market Position & Future Trends** ### **Current Market Position** - **Volume Usage:** Medium-high in automotive and agricultural sectors - **Competitive Position:** Between plain carbon steels and premium alloy steels - **Supply Chain:** Readily available from major steel producers - **Industry Acceptance:** Well-established in North American manufacturing ### **Future Developments** 1. **Clean Steel Technology:** Improved inclusion control for better fatigue performance 2. **Precision Carburizing:** Advanced atmosphere control for consistent case properties 3. **Sustainability:** Development of more energy-efficient heat treatment processes 4. **Digital Integration:** IoT monitoring of heat treatment parameters for quality assurance --- **AISI 4023** represents an optimal balance between performance and cost for a wide range of case-hardening applications. Its molybdenum addition provides meaningful improvements in hardenability and grain control compared to plain carbon steels, while maintaining cost-effectiveness for volume production. The steel's versatility makes it suitable for numerous industrial applications where reliable performance, manufacturing economy, and consistent quality are essential. For engineers and designers, AISI 4023 offers a practical solution for components requiring a durable wear surface supported by a reasonably strong, ductile core, particularly in automotive, agricultural, and general industrial equipment. -:- For detailed product information, please contact sales. -: AISI 4023 Steel, Specification Dimensions Size： Diameter 20-1000 mm Length <4015 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 4023 Steel, Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 4023 Steel, -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 4023 Steel, -:- For detailed product information, please contact sales. -:

Packing of AISI 4023 Steel, -:- 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 486 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