AISI 4145 Steel Tube,Pipe

AISI 4145 Steel Tube Product Information -:- For detailed product information, please contact sales. -: AISI 4145 Steel Tube Synonyms -:- For detailed product information, please contact sales. -:

AISI 4145 Steel Product Information -:- For detailed product information, please contact sales. -: # **AISI 4145 Steel Product Specification** ## **1. Product Overview & Classification** **AISI 4145** is a medium-high carbon chromium-molybdenum alloy steel characterized by excellent hardenability, high strength, and good wear resistance. As a member of the 41xx series with elevated carbon content (0.43-0.48%), it offers superior strength and hardenability compared to 4140 and 4142 grades, making it particularly suitable for large cross-section components requiring uniform through-hardening. **Material Family:** Chromium-Molybdenum (Cr-Mo) alloy steel **Carbon Level:** Medium-high (0.43-0.48%) **Primary Features:** High hardenability, excellent strength-to-weight ratio, good fatigue resistance ## **2. International Standards & Designations** | Region/Standard | Designation | Equivalent Standard | |-----------------|-------------|---------------------| | **United States** | AISI 4145, UNS G41450 | ASTM A29, ASTM A322, SAE J404 | | **Europe** | 1.7228 (42CrMo5) | EN 10083-3, DIN 17200 | | **Japan** | SCM445 | JIS G4105 | | **China** | 42CrMo (modified) | GB/T 3077 (similar) | | **International** | 42CrMo5 | ISO 683-18 | | **Aerospace** | - | AMS 6347 (similar) | **Note:** Direct equivalents vary by country; 4145 typically has slightly higher carbon than common European 42CrMo4. ## **3. Chemical Composition (Weight %)** | Element | Composition Range (%) | Typical Aim (%) | Metallurgical Function | |---------|----------------------|-----------------|------------------------| | **Carbon (C)** | 0.43 - 0.48 | 0.45 | Primary strengthener; provides hardenability and wear resistance | | **Manganese (Mn)** | 0.75 - 1.00 | 0.85 | Enhances hardenability, combines with S to form MnS inclusions | | **Phosphorus (P)** | ≤ 0.035 | 0.020 | Residual element (kept low for toughness) | | **Sulfur (S)** | ≤ 0.040 | 0.025 | Improves machinability; forms MnS inclusions | | **Silicon (Si)** | 0.15 - 0.35 | 0.25 | Deoxidizer, solid solution strengthener | | **Chromium (Cr)** | 0.80 - 1.10 | 0.95 | Increases hardenability, improves corrosion/oxidation resistance | | **Molybdenum (Mo)** | 0.15 - 0.25 | 0.20 | Enhances hardenability, reduces temper embrittlement, improves high-temp strength | | **Copper (Cu)** *resid* | ≤ 0.35 | 0.15 | Residual from scrap | | **Nickel (Ni)** *resid* | ≤ 0.25 | 0.10 | Residual from scrap | **Special Quality Variants:** - **4145H:** Hardenability-controlled version per ASTM A304 - **4145 Mod:** Modified with 0.0005-0.003% Boron for enhanced hardenability - **Vacuum Degassed:** Improved cleanliness for critical applications ## **4. Physical Properties** *Properties are for annealed/normalized condition unless specified* | Property | Value | Conditions | |----------|-------|------------| | **Density** | 7.85 g/cm³ (0.284 lb/in³) | At 20°C | | **Melting Point** | 1405-1500°C (2560-2730°F) | Liquidus-solidus range | | **Modulus of Elasticity (E)** | 205 GPa (29.7 × 10⁶ psi) | At 20°C | | **Shear Modulus (G)** | 80 GPa (11.6 × 10⁶ psi) | At 20°C | | **Poisson's Ratio (ν)** | 0.29 | At 20°C | | **Thermal Conductivity** | 41.2 W/m·K | At 100°C | | **Specific Heat Capacity** | 460 J/kg·K | At 20°C | | **Coefficient of Thermal Expansion** | 12.0 × 10⁻⁶ /K | 20-100°C range | | **Electrical Resistivity** | 0.24 µΩ·m | At 20°C | | **Magnetic Permeability** | Ferromagnetic | - | ## **5. Mechanical Properties by Condition** ### **Annealed Condition (Furnace Cooled)** | Property | Value Range | Typical | |----------|-------------|---------| | **Tensile Strength** | 670-800 MPa (97-116 ksi) | 735 MPa (107 ksi) | | **Yield Strength (0.2%)** | 415-550 MPa (60-80 ksi) | 485 MPa (70 ksi) | | **Elongation in 50 mm** | 22-28% | 25% | | **Reduction of Area** | 45-55% | 50% | | **Hardness (Brinell)** | 201-235 HB | 217 HB | | **Hardness (Rockwell)** | 95-102 HRB | 98 HRB | | **Machinability Rating** | 60% of B1112 | - | ### **Normalized Condition (Air Cooled)** | Property | Value Range | |----------|-------------| | **Tensile Strength** | 725-860 MPa (105-125 ksi) | | **Yield Strength** | 480-620 MPa (70-90 ksi) | | **Elongation** | 20-25% | | **Hardness** | 217-255 HB | ### **Quenched & Tempered Conditions** *Oil quenched from 845-870°C (1550-1600°F)* | Tempering Temperature | Tensile Strength | Yield Strength | Hardness | Charpy Impact (20°C) | |-----------------------|------------------|----------------|----------|----------------------| | **205°C (400°F)** | 1655-1795 MPa (240-260 ksi) | 1515-1655 MPa (220-240 ksi) | 50-54 HRC | 14-27 J (10-20 ft-lb) | | **425°C (800°F)** | 1380-1520 MPa (200-220 ksi) | 1240-1380 MPa (180-200 ksi) | 40-44 HRC | 27-41 J (20-30 ft-lb) | | **540°C (1000°F)** | 1170-1310 MPa (170-190 ksi) | 1035-1170 MPa (150-170 ksi) | 35-39 HRC | 41-54 J (30-40 ft-lb) | | **595°C (1100°F)** | 1035-1170 MPa (150-170 ksi) | 930-1035 MPa (135-150 ksi) | 31-35 HRC | 54-68 J (40-50 ft-lb) | **Hardenability Data (Jominy End-Quench):** - J₁ (1/16"): 55-60 HRC - J₄ (4/16"): 48-54 HRC - J₈ (8/16"): 42-48 HRC - J₁₂ (12/16"): 36-42 HRC - **Ideal Critical Diameter (Dᵢ):** ~3.5 inches (89 mm) in oil ## **6. Heat Treatment Guidelines** ### **Full Annealing** - **Temperature:** 815-870°C (1500-1600°F) - **Cooling:** Furnace cool at ≤15°C/hour (27°F/hour) to 595°C (1100°F), then air cool - **Resulting Hardness:** 201-235 HB ### **Normalizing** - **Temperature:** 870-900°C (1600-1650°F) - **Cooling:** Still air - **Resulting Hardness:** 217-255 HB ### **Hardening (Quenching)** - **Austenitizing:** 845-870°C (1550-1600°F) - **Soak Time:** 30 min/inch of thickness minimum - **Quench Medium:** Oil (preferred), polymer, or agitated water for large sections - **Preheat:** 650-700°C (1200-1290°F) recommended for sections >50 mm ### **Tempering** - **Temperature Range:** 205-650°C (400-1200°F) - **Time:** 1-2 hours/inch of thickness - **Cooling:** Air cool (rapid cooling through 375-575°C range to avoid temper embrittlement) ## **7. Manufacturing & Processing Characteristics** ### **Machinability** | Condition | Relative Rating | Cutting Speed (m/min) | Tool Recommendations | |-----------|----------------|----------------------|----------------------| | **Annealed** | 60% (Fair) | 30-45 | Carbide or HSS with positive rake | | **Normalized** | 55% (Fair-Poor) | 25-40 | Carbide preferred | | **Hardened (30+ HRC)** | 35% (Poor) | 15-30 | C2/C6 carbide, ceramic for finishing | | **Turning** | - | 25-60 SFM | TiCN or AlTiN coated carbide | | **Drilling** | - | 10-20 SFM | HSS or carbide-tipped drills | | **Tapping** | - | 40% reduced speed | Premium HSS-E taps | ### **Weldability** - **Rating:** Poor (requires precautions) - **Preheat Temperature:** 200-315°C (400-600°F) - **Interpass Temperature:** 200-315°C (400-600°F) - **Post-Weld Heat Treatment:** Mandatory (temper at 595-650°C/1100-1200°F) - **Filler Metals:** AWS E10018-D2, E11018-D2, or matching composition rods - **Welding Processes:** SMAW, GTAW, GMAW with preheat ### **Forgability** - **Heating Temperature:** 1150-1200°C (2100-2190°F) - **Forging Range:** 1200-900°C (2190-1650°F) - **Finish Forging:** >870°C (1600°F) - **Post-Forging:** Anneal or normalize to relieve stresses ### **Surface Hardening Compatibility** - **Induction Hardening:** Excellent (surface to 55-62 HRC, core 35-45 HRC) - **Flame Hardening:** Good - **Nitriding:** Good (typical case depth 0.25-0.50 mm, hardness 65-72 HRC) - **Carburizing:** Suitable (produces very hard case, 60+ HRC) ## **8. Product Applications** ### **Oil & Gas Industry** - **Drill collars** and **heavy-weight drill pipe** - **Tool joints** (API Spec 7-1, 7-2) - **Kelly bars** and **drilling stems** - **Sucker rods** for deep wells - **Valve components** for high-pressure service - **BOP (Blowout Preventer) components** ### **Heavy Equipment & Construction** - **Track rollers** and **idlers** for mining equipment - **Final drive gears** in excavators and bulldozers - **Pivot pins** and **bushings** (75-150 mm diameter) - **Crusher components** and **hammer mill parts** - **Dredge cutter teeth** and **components** ### **Power Transmission** - **Large gear blanks** (>150 mm diameter) - **Shafts** for heavy machinery - **Sprockets** for conveyor systems - **Couplings** and **flanges** - **Crane wheel rims** and **travel wheels** ### **Automotive & Heavy Truck** - **Crankshafts** for large diesel engines - **Axle shafts** for Class 8 trucks - **Transmission shafts** and **gears** - **King pins** and **steering components** - **Wheel hubs** for heavy-duty applications ### **Industrial Manufacturing** - **Extruder screws** for plastics and rubber - **Press frames** and **components** - **Rolling mill rolls** (backup and intermediate) - **Die blocks** and **tooling components** - **Mandrels** for tube and pipe manufacturing ## **9. Available Product Forms & Sizes** | Product Form | Typical Size Range | Common Standards | |--------------|-------------------|------------------| | **Round Bars** | 10-400 mm (0.375-16 in) diameter | ASTM A29, EN 10083-3 | | **Square Bars** | 10-150 mm (0.375-6 in) | ASTM A29 | | **Hexagonal Bars** | 10-100 mm (0.375-4 in) | ASTM A29 | | **Flat Bars** | Up to 300 × 75 mm (12 × 3 in) | ASTM A29 | | **Billets** | 100-400 mm (4-16 in) square | For forging | | **Forgings** | Custom shapes and sizes | ASTM A668 | | **Seamless Tubing** | 25-250 mm (1-10 in) OD | ASTM A519 | | **Plate** | Up to 150 mm (6 in) thick | ASTM A829 | ## **10. Comparison with Similar Grades** | Property/Characteristic | AISI 4145 | AISI 4140 | AISI 4150 | 4340 | |-------------------------|-----------|-----------|-----------|------| | **Carbon Range (%)** | 0.43-0.48 | 0.38-0.43 | 0.48-0.53 | 0.38-0.43 | | **Typical Hardness (Q&T)** | 35-45 HRC | 28-40 HRC | 40-50 HRC | 35-48 HRC | | **Hardenability (Dᵢ inches)** | ~3.5 | ~2.8 | ~4.0 | ~4.5 | | **Strength (Q&T, MPa)** | 1170-1520 | 1030-1380 | 1240-1655 | 1170-1520 | | **Toughness** | Good | Very Good | Fair-Good | Excellent | | **Cost Relative** | 100% | 95% | 105% | 140% | | **Best For** | Large sections, wear resistance | General purpose, toughness | Extreme wear, very large sections | Critical toughness applications | ## **11. Quality Specifications & Testing** ### **Standard Testing Requirements** 1. **Chemical Analysis:** Spectrographic or wet chemical 2. **Tensile Testing:** Per ASTM A370 3. **Hardness Testing:** Brinell or Rockwell per ASTM E10/E18 4. **Macroetch Testing:** For soundness (ASTM E381) 5. **Grain Size:** ASTM E112 (typically 5-8) ### **Enhanced Testing Options** - **Ultrasonic Testing:** For internal defects (ASTM A388) - **Magnetic Particle Inspection:** Surface defects (ASTM A275/A966) - **Charpy Impact Testing:** Multiple temperatures if specified - **Jominy Hardenability:** For 4145H grade - **Sulfur Print:** Inclusion morphology assessment ### **Certifications Available** - **Mill Test Certificate 2.1** (EN 10204) - **Material Test Report** (ASTM A29) - **Third-Party Inspection Reports** - **Country of Origin Certificates** - **Nadcap Accreditation** for aerospace applications ## **12. Design Considerations** ### **Advantages of AISI 4145** 1. **Excellent Hardenability:** Suitable for large cross-sections (up to 100 mm fully hardened) 2. **High Strength Potential:** Ultimate tensile up to 1800 MPa achievable 3. **Good Wear Resistance:** Particularly in hardened conditions 4. **Fatigue Resistance:** Suitable for cyclic loading applications 5. **Cost-Effective:** More economical than nickel-alloy steels like 4340 6. **Versatility:** Can be used in various heat-treated conditions ### **Limitations & Considerations** 1. **Weldability:** Poor; requires extensive precautions 2. **Machinability:** Moderate in annealed condition, poor when hardened 3. **Notch Sensitivity:** Moderate to high in hardened conditions 4. **Temper Embrittlement:** Susceptible between 375-575°C; rapid cooling through this range recommended 5. **Corrosion Resistance:** Limited; requires protection in corrosive environments ### **Design Recommendations** - **Fillets and Radii:** Minimum R3 mm (0.125 in) on all corners - **Section Transitions:** Gradual changes to minimize stress concentrations - **Surface Finish:** Critical areas should be machined to 3.2 µm Ra or better - **Heat Treatment:** Specify required hardness range, not just tempering temperature - **Quality Level:** Specify testing requirements based on application criticality ## **13. Economic & Supply Considerations** - **Global Availability:** Widely produced in North America, Europe, and Asia - **Lead Times:** 4-8 weeks for standard sizes and conditions - **Minimum Orders:** Typically 2,000-5,000 lbs for mill orders - **Cost Factors:** 1.4-1.8 × 1018/1020 steel cost - **Stock Availability:** Common sizes often available from service centers - **Recyclability:** 100% recyclable as ferrous scrap ## **14. Technical Notes** ### **Microstructural Characteristics** - **As-Annealed:** Ferrite + pearlite (coarse) - **Normalized:** Finer pearlite + ferrite - **Quenched & Tempered:** Tempered martensite with fine carbides - **Prior Austenite Grain Size:** Typically ASTM 5-8 with proper heat treatment ### **Special Processing Considerations** 1. **Decarburization:** Up to 0.5 mm per side in hot-rolled products; specify machined oversize if critical 2. **Residual Stresses:** Significant in as-rolled condition; stress relieve before precision machining 3. **Size Effect:** Mechanical properties decrease with increasing section size 4. **Directionality:** Properties vary slightly with grain flow direction ### **Fatigue Data (Typical)** - **Endurance Limit (σₑ):** ~550 MPa (80 ksi) for polished specimens - **Fatigue Ratio (σₑ/UTS):** 0.45-0.50 - **Surface Finish Factor:** Critical for fatigue performance --- ## **Summary: Application Selection Guidelines** **Choose AISI 4145 when:** - Component cross-section exceeds 50 mm (2 inches) - High strength (1000+ MPa) combined with moderate toughness is required - Wear resistance is important but surface hardening is not feasible - Cost is a consideration but 4140 lacks sufficient hardenability - Component will be heat treated after rough machining **Consider alternatives when:** - Superior toughness is required (consider 4340) - Very high hardness (>50 HRC) is needed (consider 4150 or tool steels) - Excellent weldability is essential (consider lower carbon grades) - Corrosion resistance is critical (consider stainless steels) - Extreme impact resistance is needed (consider 300M or similar) --- **Disclaimer:** This product specification is for informational purposes only. The information presented reflects typical properties and characteristics but may not represent all possible conditions or manufacturer variations. For critical applications, consult with materials engineers, review current industry standards, and conduct appropriate testing to verify material suitability. Always refer to the manufacturer's data sheets and certifications for specific product information. -:- For detailed product information, please contact sales. -: AISI 4145 Steel Specification Dimensions Size： Diameter 20-1000 mm Length <4044 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 4145 Steel Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 4145 Steel Tube -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 4145 Steel Tube -:- For detailed product information, please contact sales. -:

Packing of AISI 4145 Steel Tube -:- 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 Tube 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 515 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