SAE 5145 Alloy Steel Capillary

SAE 5145 Alloy Steel Capillary, Composition Spec Product Information -:- For detailed product information, please contact sales. -: SAE 5145 Alloy Steel Capillary, Composition Spec Synonyms -:- For detailed product information, please contact sales. -:

SAE 5145 Alloy Steel, Composition Spec Product Information -:- For detailed product information, please contact sales. -: # **SAE 5145 Alloy Steel - Technical Data Sheet** ## **1. Product Overview** **SAE 5145** is a medium-high carbon chromium alloy steel designed for applications requiring **superior strength, wear resistance, and good hardenability**. With a nominal carbon content of 0.45% and chromium content of approximately 1.00%, this steel provides excellent response to heat treatment, achieving high hardness levels while maintaining adequate toughness for demanding applications. This alloy is particularly suitable for components subjected to **heavy loads, impact, and abrasive wear**, where the combination of through-hardening capability and chromium-enhanced properties offers significant advantages over plain carbon steels. SAE 5145 is widely used in automotive, industrial, and heavy equipment applications where durability and reliability are critical. --- ## **2. Chemical Composition (SAE J404/J412)** | Element | Composition Range (%) | Metallurgical Function | |---------|----------------------|------------------------| | **Carbon (C)** | 0.43 - 0.48 | Primary hardening element; provides high strength and wear resistance | | **Manganese (Mn)** | 0.70 - 0.90 | Enhances hardenability, contributes to strength, aids in deoxidation | | **Phosphorus (P)** | ≤ 0.035 | Residual impurity; minimized for improved toughness | | **Sulfur (S)** | ≤ 0.040 | Residual element; typically low for uniform mechanical properties | | **Silicon (Si)** | 0.15 - 0.35 | Deoxidizer; provides solid solution strengthening | | **Chromium (Cr)** | 0.80 - 1.10 | **Key alloying element**; significantly improves hardenability, wear resistance, and tempering stability | | **Iron (Fe)** | Balance | Base metal | **Material Designations:** - **SAE/AISI:** 5145 - **UNS:** G51450 - **Common Forms:** Round bars, flat bars, forging stock, seamless tubing - **Available Conditions:** Annealed, normalized, hot rolled, cold drawn, heat treated --- ## **3. Physical & Mechanical Properties** ### **As-Supplied Conditions:** **Annealed Condition (for machining):** - **Hardness:** 197-241 HB (93-100 HRB) - **Tensile Strength:** 655-860 MPa (95-125 ksi) - **Yield Strength:** 415-620 MPa (60-90 ksi) - **Elongation (in 2"):** 16-22% - **Reduction of Area:** 35-45% - **Machinability:** 40-45% (relative to 1212 steel = 100%) **Normalized Condition:** - **Hardness:** 212-255 HB - **Tensile Strength:** 725-930 MPa (105-135 ksi) - **Yield Strength:** 450-690 MPa (65-100 ksi) - **Grain Size:** ASTM 5-7 ### **Heat Treated Properties (Through-Hardened):** **Standard Heat Treatment:** - **Austenitizing:** 830-855°C (1525-1575°F) - **Quenching:** Oil (preferred for sections up to 75mm) - **Tempering:** 150-600°C (300-1110°F) depending on requirements **Typical Properties After Heat Treatment:** | Tempering Temperature | Hardness (HRC) | Tensile Strength | Yield Strength | Charpy V-Notch Impact | |----------------------|----------------|------------------|----------------|-----------------------| | As-quenched | 56-61 | - | - | 10-15 J | | 200°C (400°F) | 52-57 | 1750-1950 MPa | 1500-1700 MPa | 12-20 J | | 400°C (750°F) | 42-47 | 1350-1550 MPa | 1150-1350 MPa | 25-40 J | | 550°C (1020°F) | 32-37 | 1050-1250 MPa | 900-1100 MPa | 40-60 J | ### **Hardenability Data:** - **Ideal Critical Diameter (D₁) in oil:** 75-90 mm - **Maximum section for effective hardening:** ~100 mm in oil quench - **Jominy distance to 50 HRC:** ~J14-J18 - **Jominy distance to 40 HRC:** ~J22-J28 - **Quench severity required:** H=0.35-0.50 (moderate oil agitation) ### **Physical Properties:** - **Density:** 7.85 g/cm³ (0.284 lb/in³) - **Melting Point:** 1480-1520°C (2695-2770°F) - **Modulus of Elasticity:** 205 GPa (29,700 ksi) - **Shear Modulus:** 80 GPa (11,600 ksi) - **Poisson's Ratio:** 0.29 - **Thermal Conductivity:** 43.5 W/m·K at 100°C - **Coefficient of Thermal Expansion:** 12.0 μm/m·°C (20-100°C) - **Specific Heat:** 460 J/kg·K at 20°C --- ## **4. Product Applications** ### **Automotive & Transportation:** - **Heavy-duty axle shafts** for trucks and commercial vehicles - **Transmission components:** Gears, shafts, synchronizer rings - **Steering system parts:** Drag links, pitman arms, steering knuckles - **Suspension components:** Leaf springs, torsion bars, stabilizer links - **Engine components:** Crankshafts (medium duty), camshafts ### **Industrial Machinery:** - **Heavy-duty gears** and pinions for industrial gearboxes - **Shafts** for pumps, compressors, and turbines - **Machine tool components:** Spindles, arbors, lead screws - **Hydraulic components:** Piston rods, cylinder barrels, valve bodies - **Agricultural equipment:** Implement shafts, gear components, tillage tools ### **Heavy Equipment & Construction:** - **Construction machinery:** Track pins, roller shafts, pivot pins - **Mining equipment:** Drill rods, crusher components, conveyor drives - **Material handling:** Crane hooks, sheave shafts, hoist drums - **Earthmoving equipment:** Bucket teeth, adapter systems, wear plates ### **Tooling & Special Applications:** - **Forging dies** and die blocks - **Plastic injection molds** (cores and cavities) - **High-strength fasteners** and studs - **Wear-resistant components** in material processing - **Hand tools:** Impact sockets, wrenches, pry bars ### **Typical Hardness Requirements by Application:** | Application | Hardness Range | Heat Treatment | Section Size Limit | |-------------|----------------|----------------|-------------------| | Heavy Gears | 35-42 HRC | Q&T @ 450-550°C | Up to 80mm | | Shafts | 30-40 HRC | Q&T @ 500-600°C | Up to 100mm | | Fasteners | 38-48 HRC | Q&T @ 350-450°C | Up to 40mm | | Wear Parts | 45-55 HRC | Q&T @ 200-350°C | Up to 50mm | | Tools | 50-58 HRC | Q&T @ 150-250°C | Up to 30mm | --- ## **5. International Standards & Equivalent Grades** ### **Primary Standards:** | Standard | Designation | Specification Document | |----------|-------------|------------------------| | **SAE/AISI** | **5145** | SAE J404, J412 | | **UNS** | **G51450** | Unified Numbering System | | **ASTM** | - | A322 (Standard for Alloy Steel Bars) | ### **Global Equivalent Grades:** | Country/Region | Standard | Equivalent Grade | Notes | |----------------|----------|-----------------|-------| | **International (ISO)** | ISO 683-11 | **45Cr4** | Type 1.7039 | | **Europe (EN)** | EN 10083-3 | **45Cr4** | Designation 1.7039 | | **Germany** | DIN 17200 | **45Cr4** | Direct equivalent | | **Japan** | JIS G4105 | **SCr445** | Very similar composition | | **China** | GB/T 3077 | **45Cr** (45铬) | Chinese equivalent | | **France** | NF A35-552 | **45C4** | French standard | | **United Kingdom** | BS 970 | **534A99** | British specification | | **Sweden** | SS 14 2541 | **2245** | Swedish standard | ### **H-Grade Variant:** - **SAE 5145H:** Available with guaranteed hardenability bands per SAE J1268 ### **Related Processing Standards:** - **Heat Treatment:** AMS 2759, ASTM A29 - **Forging:** ASTM A788 - **Bars:** ASTM A322, A304 - **Cleanliness:** ASTM E45, AMS 2301 (for special qualities) - **Case Hardening:** ASTM A534 (if applicable) --- ## **6. Manufacturing & Processing Characteristics** ### **Hot Working Parameters:** - **Forging Temperature:** 1150-850°C (2100-1560°F) - **Hot Rolling:** 1100-900°C (2010-1650°F) - **Finish Forging Temperature:** ≥850°C (1560°F) - **Post-hot work cooling:** Slow cool (furnace or insulated container) to prevent cracking ### **Heat Treatment Guidelines:** **1. Annealing (for Machining):** - **Full Anneal:** 820-850°C, furnace cool to 600°C at ≤20°C/hour, then air cool - **Spheroidize Anneal:** 740-760°C, hold 6-10 hours, furnace cool to 650°C at ≤10°C/hour - **Resulting Hardness:** 197-229 HB **2. Normalizing:** - **Temperature:** 860-890°C - **Soak Time:** 30 minutes per inch minimum - **Cooling:** Still air - **Purpose:** Grain refinement and homogenization **3. Hardening:** - **Austenitizing:** 835-850°C (1535-1560°F) - **Soak Time:** 20-30 minutes per inch of thickness - **Pre-heat:** 650-700°C recommended for sections >50mm - **Quenching Medium:** Oil (ISO VG 68-100), moderate to strong agitation - **Martempering Option:** Quench into hot oil at 150-200°C for distortion control **4. Tempering:** - **Begin Tempering:** When parts reach 50-100°C after quenching - **Temperature Range:** 150-650°C based on required hardness - **Time:** Minimum 1.5 hours per inch of thickness - **Cooling:** Air cool; rapid cooling through 350-575°C range strongly recommended ### **Machinability:** - **Optimal Condition:** Annealed (spheroidized, 197-229 HB) - **Cutting Speed:** 30-45 m/min with carbide tools - **Feed Rate:** 0.10-0.20 mm/rev for finishing, 0.25-0.40 mm/rev for roughing - **Tool Material:** Carbide grades C2-C5 or premium cobalt HSS - **Tool Geometry:** Positive rake (5-7°), sharp cutting edges, chip breakers essential - **Coolant:** Emulsion or neat oil essential for tool life ### **Weldability:** - **Rating:** Very poor (not generally recommended) - **If welding necessary:** Pre-heat 300-350°C minimum - **Interpass Temperature:** 300-350°C - **Post-weld Heat Treatment:** Complete re-austenitize, quench, and temper required - **Welding Processes:** SMAW with low-hydrogen electrodes (E11018-D2) - **Critical Restriction:** Weld-affected zones will have significantly different properties --- ## **7. Quality Control & Inspection** ### **Standard Testing Requirements:** - **Chemical Analysis:** ASTM A751 (spectrochemical or wet methods) - **Hardness Testing:** ASTM E10 (Brinell), E18 (Rockwell) - **Tensile Testing:** ASTM E8/E8M - **Impact Testing:** ASTM E23 (Charpy V-notch) if specified - **Microstructural Examination:** ASTM E112 (grain size), E45 (inclusions) ### **Typical Quality Parameters:** - **Grain Size:** ASTM 5-7 (fine to medium) - **Decarburization:** ≤0.50 mm total per side (as-supplied) - **Surface Quality:** Free from seams, laps, cracks, and excessive scale - **Straightness:** Per commercial standards or customer specifications - **Ultrasonic Testing:** Available for internal quality verification ### **Special Quality Grades:** - **Aircraft Quality:** Per AMS specifications with enhanced cleanliness requirements - **Bearing Quality:** For high fatigue resistance applications - **Vacuum Degassed:** For improved cleanliness and reduced gas content - **Electroslag Remelted (ESR):** For ultra-high purity and homogeneity (special applications) --- ## **8. Technical Performance Characteristics** ### **Fatigue Properties:** - **Rotating Bending Fatigue Limit:** 550-630 MPa (80-91 ksi) at 40 HRC - **Fatigue Ratio (σe/UTS):** 0.42-0.48 - **Notch Sensitivity Index (q):** 0.85-0.90 - **Surface Finish Effect:** Polished surfaces improve fatigue limit by 25-35% - **Shot Peening Benefit:** Increases fatigue strength by 30-50% ### **Wear Resistance:** - **Abrasive Wear Resistance:** Excellent at hardness >45 HRC - **Adhesive Wear (scuffing resistance):** Good with proper lubrication - **Contact Fatigue (pitting resistance):** Very good for heavy-duty gear applications - **Break-in Characteristics:** Good with proper surface finish (0.8-1.6 μm Ra) ### **Fracture Toughness & Impact Properties:** - **Ductile-to-Brittle Transition Temperature:** 0°C to -20°C (depending on heat treatment) - **Fracture Toughness (K₁C):** 45-65 MPa√m at 40 HRC - **Impact Energy:** Highly dependent on tempering temperature and prior microstructure - **Temper Embrittlement Susceptibility:** High; must avoid slow cooling through 350-575°C range ### **Temperature Effects:** - **Maximum Continuous Service:** 300°C (570°F) - **Short-term Exposure:** Up to 400°C (750°F) acceptable - **Temper Resistance:** Good up to 350°C (660°F) - **Cryogenic Service:** Not recommended below -20°C (-4°F) - **Thermal Fatigue Resistance:** Moderate to poor (limited by high carbon content) --- ## **9. Design & Application Considerations** ### **Optimal Application Parameters:** - **Section Size Range:** 40-100 mm diameter for through-hardening - **Stress Concentration:** Generous fillets (R ≥ 0.75 × section change) - **Surface Finish Requirements:** 0.8-3.2 μm Ra for optimal performance - **Dimensional Tolerance:** IT8-IT10 achievable with post-heat treatment grinding ### **Advantages of SAE 5145:** ✅ **Excellent hardenability** for large sections ✅ **High strength capability** (up to 1900 MPa tensile) ✅ **Superior wear resistance** when properly heat treated ✅ **Good fatigue performance** for heavy cyclic loading ✅ **Cost-effective** compared to nickel-alloyed steels for similar applications ✅ **Excellent response** to surface hardening processes ### **Limitations & Considerations:** ⚠️ **Limited toughness** at high hardness levels (>45 HRC) ⚠️ **Welding extremely difficult** and generally not recommended ⚠️ **Poor corrosion resistance** (requires protective coatings) ⚠️ **Machinability fair to poor**, requires proper tooling and conditions ⚠️ **High temper embrittlement susceptibility** ⚠️ **Not suitable** for impact-loaded applications at high hardness ⚠️ **Size limitations** for uniform hardening (>125mm typically not recommended) ### **Comparison with Similar Grades:** | Property | 5145 | 5150 | 4140 | 4340 | 1045 | |----------|------|------|------|------|------| | **Carbon Range** | 0.43-0.48 | 0.48-0.53 | 0.38-0.43 | 0.38-0.43 | 0.43-0.50 | | **Chromium Content** | 0.80-1.10 | 0.70-0.90 | 0.80-1.10 | 0.70-0.90 | - | | **Typical Hardness** | 40-50 HRC | 42-52 HRC | 38-48 HRC | 40-50 HRC | 20-30 HRC | | **Hardenability** | Excellent | Excellent | Very Good | Excellent | Fair | | **Toughness** | Fair | Fair to Poor | Good | Excellent | Good | | **Primary Use** | Heavy gears, shafts | Heavy components | General purpose | Critical parts | General purpose | | **Relative Cost** | 1.10 | 1.12 | 1.15 | 1.30 | 0.80 | --- ## **10. Special Processing Options** ### **Surface Hardening Methods:** 1. **Induction Hardening:** - **Surface Hardness:** 58-62 HRC - **Case Depth:** 2.0-10.0 mm (adjustable) - **Applications:** Selective hardening of wear surfaces on shafts, gears, rolls 2. **Flame Hardening:** - **For:** Very large or irregularly shaped components - **Control:** Critical to prevent overheating and cracking 3. **Nitriding:** - **Surface Hardness:** 65-72 HRC (converted) - **Case Depth:** 0.3-0.8 mm - **Benefits:** Excellent wear and fatigue resistance with minimal distortion - **Note:** Requires prior heat treatment to desired core properties ### **Thermomechanical Processing:** - **Controlled Rolling:** For improved toughness in specific orientations - **Ausforming:** For ultra-high strength (requires specialized equipment) - **Intercritical Heat Treatment:** For optimized combination of strength and toughness (limited due to carbon content) - **Austempering:** For improved toughness at given hardness level (applicable range limited) ### **Finishing Operations:** - **Grinding:** Essential after heat treatment for precision dimensions and surface finish - **Honing:** For improved surface characteristics and dimensional accuracy - **Shot Peening:** Highly recommended for compressive surface stresses and improved fatigue life - **Superfinishing:** For optimal surface texture (0.1-0.4 μm Ra) in bearing applications - **Coating/Plating:** For corrosion protection (phosphate, black oxide, hard chrome, electroless nickel) --- ## **11. Environmental & Economic Considerations** ### **Material Safety & Handling:** - **General Safety:** Standard steel handling procedures apply - **Machining:** Use appropriate ventilation and dust collection systems - **Heat Treatment:** Standard furnace safety and quench oil fire prevention essential - **Disposal:** Recyclable as ferrous scrap; no hazardous constituents ### **Environmental Compliance:** - **REACH Compliance:** Fully compliant (no SVHC substances in base material) - **RoHS Compliance:** Does not contain restricted hazardous substances - **Recyclability:** 100% recyclable as ferrous scrap with high recovery value - **Carbon Footprint:** Typical for alloy steel production ### **Economic Factors:** - **Material Cost:** Moderate to high (higher than lower carbon grades) - **Processing Cost:** Higher due to heat treatment requirements and machining difficulty - **Tooling Cost:** Higher than for more machinable steels - **Life Cycle Cost:** Favorable for durable components with long service life in demanding applications - **Availability:** Readily available from major steel producers worldwide ### **Sustainability Considerations:** - Long service life reduces replacement frequency and resource consumption - Energy efficient compared to some specialty alloys for similar applications - Compatible with modern, efficient manufacturing processes - Fully recyclable at end of service life with high scrap value - Can be produced with significant recycled steel content (typical 30-50%) --- **Technical Note:** SAE 5145 represents a high-performance chromium alloy steel optimized for applications requiring maximum hardness and wear resistance in medium to large sections. Its 0.45% carbon content provides near-maximum hardness potential for chromium steels while maintaining some toughness when properly tempered. This grade is particularly suitable for components where wear resistance is the primary concern and where the high carbon content's impact on toughness can be managed through proper design and heat treatment. **Revision:** 1.1 **Date:** October 2023 **Disclaimer:** This technical data is for informational purposes. Actual properties depend on specific processing history, heat treatment parameters, section size, and manufacturing variables. Always consult with material suppliers and conduct application-specific testing for critical components. Properties may vary between manufacturers, heat lots, and processing conditions. The information presented represents typical values and ranges; specific applications may require modification of parameters or selection of alternative materials. -:- For detailed product information, please contact sales. -: SAE 5145 Alloy Steel, Composition Spec Specification Dimensions Size： Diameter 20-1000 mm Length <4118 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. -: SAE 5145 Alloy Steel, Composition Spec Properties -:- For detailed product information, please contact sales. -:

Applications of SAE 5145 Alloy Steel Capillary, Composition Spec -:- For detailed product information, please contact sales. -: Chemical Identifiers SAE 5145 Alloy Steel Capillary, Composition Spec -:- For detailed product information, please contact sales. -:

Packing of SAE 5145 Alloy Steel Capillary, Composition Spec -:- 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 Capillary 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 589 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