AISI 5150H Steel, oil quenched

AISI 5150H Steel, oil quenched from 830°C (1525°F), 540°C (1000°F) temper Product Information -:- For detailed product information, please contact sales. -: AISI 5150H Steel, oil quenched from 830°C (1525°F), 540°C (1000°F) temper Synonyms -:- For detailed product information, please contact sales. -:

AISI 5150H Steel, oil quenched from 830°C (1525°F), 540°C (1000°F) temper Product Information -:- For detailed product information, please contact sales. -: # **Product Introduction: AISI 5150H Steel, Heat Treated to 830°C Oil Quenched + 540°C Tempered Condition** ## **Executive Summary** **AISI 5150H steel, oil quenched from 830°C (1525°F) and tempered at 540°C (1000°F),** represents this premium-grade alloy steel in its **optimized, ready-for-service condition**, achieving certified mechanical properties with exceptional consistency. The "H" designation guarantees compliance with **SAE J1268 hardenability bands**, ensuring that this specific heat treatment regimen yields predictable results across all production batches. This thermal processing transforms the steel into a **fine tempered martensitic microstructure** that delivers an outstanding balance of **high strength (1100-1300 MPa tensile), good toughness (30-45 J impact), and excellent wear resistance** at approximately 38-43 HRC. This condition is engineered for **critical, dynamically loaded components** in automotive drivetrains, heavy machinery, and industrial equipment where reliability, consistency, and performance are paramount. --- ## **1. Chemical Composition & Hardenability Certification** The chemical composition is tightly controlled to ensure both compliance with hardenability bands and optimal response to the specific 830°C/540°C heat treatment. | Element | Composition Range (%) | Typical Target (%) | Metallurgical Role in 830°C OQ + 540°C Temper | |---------|----------------------|-------------------|-----------------------------------------------| | **Carbon (C)** | 0.48 - 0.53 | 0.50 | **Fundamental strength element.** At 0.50%, achieves full martensite formation during 830°C oil quench (as-quenched hardness ~57-61 HRC). During 540°C tempering, enables precipitation of fine transition carbides while maintaining substantial hardness. | | **Manganese (Mn)** | 0.70 - 0.90 | 0.80 | **Ensures consistent hardenability.** Tight range guarantees uniform through-hardening during oil quenching from 830°C across all production batches. | | **Chromium (Cr)** | 0.70 - 0.90 | 0.80 | **Critical for tempering performance.** Promotes **secondary hardening** at 540°C through formation of chromium-rich carbides (Cr₇C₃, Cr₂₃C₆). These precipitates provide exceptional tempering resistance and directly contribute to the 38-43 HRC final hardness. | | **Silicon (Si)** | 0.15 - 0.35 | 0.25 | **Solid solution strengthener & tempering stabilizer.** Increases tempering resistance, helping maintain strength at 540°C while reducing susceptibility to temper embrittlement. | | **Phosphorus (P)** | ≤ 0.025 | 0.015 | **Tighter control than standard 5150.** Minimizes temper embrittlement risk, particularly important when tempering at 540°C. | | **Sulfur (S)** | ≤ 0.025 | 0.018 | **Controlled for optimal pre-heat-treatment machinability** while maintaining transverse ductility in final tempered condition. | **H-Grade Certification Impact:** - **Guaranteed Hardenability:** Material certified to meet SAE J1268 bands ensures uniform response to 830°C austenitizing - **Predictable As-Quenched State:** Consistent prior austenite grain size and martensite formation - **Controlled Tempering Response:** Narrow range of final properties due to consistent chemistry and microstructure - **Batch-to-Batch Consistency:** All heats yield mechanical properties within specified narrow bands **Metallurgical Transformation:** 1. **830°C Austenitizing:** Complete austenitization with controlled grain growth (ASTM 8-10) 2. **Oil Quenching:** Formation of high-carbon martensite with minimal retained austenite 3. **540°C Tempering:** - Precipitation of ε-carbides and alloy carbides - Recovery of martensitic structure - Optimal stress relief 4. **Final Structure:** **Tempered lath martensite** with uniform dispersion of **fine alloy carbides** (50-150 nm) --- ## **2. Physical & Mechanical Properties (Heat Treated Condition)** ### **Physical Properties** | Property | Value / Range | Notes for Heat Treated Condition | |----------|---------------|----------------------------------| | **Density** | 7.85 g/cm³ | Unchanged by heat treatment | | **Modulus of Elasticity (E)** | **200 - 210 GPa** | Slightly increased compared to normalized state | | **Shear Modulus (G)** | 80 - 83 GPa | Important for torsional applications | | **Poisson's Ratio** | 0.29 | - | | **Thermal Conductivity** | 41 - 45 W/m·K | Reduced compared to annealed due to martensitic structure | | **Coefficient of Thermal Expansion** | 11.8 - 12.3 ×10⁻⁶/K | 20-100°C range | | **Specific Heat Capacity** | 480 - 500 J/kg·K | - | | **Electrical Resistivity** | 0.25 - 0.30 μΩ·m | Higher than annealed state | ### **Mechanical Properties (830°C OQ + 540°C Temper)** *These properties represent guaranteed minimums achievable with this heat treatment on certified 5150H material.* | Property | Certified Range | Significance for Design | |----------|-----------------|-------------------------| | **Hardness** | **363 - 444 HB** / **38 - 43 HRC** | **Optimal service hardness.** Provides excellent wear resistance with maintained toughness. Narrow range (±2 HRC) guaranteed by H-grade certification. | | **Tensile Strength** | **1100 - 1300 MPa** (160 - 188 ksi) | **High strength level.** Consistent within ±50 MPa due to H-grade control. | | **Yield Strength (0.2% Offset)** | **950 - 1150 MPa** (138 - 167 ksi) | Excellent resistance to permanent deformation. High yield-to-tensile ratio (~0.86-0.88). | | **Elongation (in 50mm)** | **12 - 16%** | Good ductility for the high strength level. Consistent due to controlled microstructure. | | **Reduction of Area** | **40 - 50%** | Good micro-ductility. Typically 40-45% at this hardness. | | **Charpy V-Notch Impact Energy** | **30 - 45 J** (at 20°C) | **Certified toughness.** Minimum typically specified as 28 J for critical applications. | | **Fatigue Strength (Rotating Bending, R=-1)** | **~500 - 550 MPa** | High endurance limit (~0.42-0.45 of tensile strength). | | **Fracture Toughness (K₁c)** | ~65 - 85 MPa√m | Good resistance to crack propagation for the hardness level. | | **Shear Strength** | ~700 - 800 MPa | Important for torsional loading applications. | ### **Heat Treatment Process Details:** **Process Control Requirements for H-Grade:** 1. **Austenitizing (830°C ±10°C):** - Temperature uniformity: ±5°C within furnace - Soak time: 20-30 minutes per inch minimum - Atmosphere control: Protective atmosphere required 2. **Quenching (Oil, 40-60°C):** - Medium: Fast oil (ISO VG 68 or equivalent) - Agitation: Moderate to high for consistent cooling - As-quenched hardness: 57-61 HRC (certified consistency) 3. **Tempering (540°C ±10°C):** - Time: 1.5-2.5 hours per inch of thickness - Cooling: Air cool (rapid cooling recommended) - Double tempering: Often specified for critical applications **Property Consistency Advantage of H-Grade:** - **Hardness Variation:** ±1.5 HRC within a batch (vs. ±3-4 HRC for standard grade) - **Tensile Strength Variation:** ±40 MPa within a heat - **Impact Energy Variation:** ±8 J within specification - **Distortion Consistency:** Predictable dimensional changes --- ## **3. Product Applications (In This Heat Treated Condition)** This is the **certified, ready-for-service condition** for high-performance components requiring guaranteed consistency. ### **Critical Application Sectors:** **Automotive & Heavy Vehicle:** - **Transmission Components:** Heavy-duty gears, synchronizers, shafts requiring certified hardness consistency - **Drivetrain Components:** Axle shafts for medium/heavy trucks, differential gears - **Suspension Components:** Heavy-duty torsion bars, stabilizer bars - **Engine Components:** High-stress fasteners, camshafts for performance applications **Heavy Equipment & Construction:** - **Excavator Components:** Bucket teeth adapters, pivot pins, linkage components - **Crane & Hoist Components:** Sheave pins, boom connection pins, hook blocks - **Earthmoving Equipment:** Cutting edges, grader blades, scarifier teeth - **Mining Equipment:** Crusher components, drill bits, hammer mill parts **Industrial Manufacturing:** - **Machine Tool Components:** Heavy-duty spindles, arbors, tool holders - **Material Handling:** Conveyor system components subject to abrasive wear - **Forging & Stamping:** Dies for non-ferrous metals and lower-strength steels - **Pump & Valve Components:** Shafts, sleeves for abrasive service conditions **Tooling & Cutting Applications:** - **Industrial Knives:** Slitter knives, shear blades, cutting blades - **Agricultural Tools:** Plow shares, disc blades, chopper knives - **Wood Processing:** Chipper knives, planer knives, debarker tools ### **Why This Specific Heat Treatment on 5150H?** | Design Requirement | 5150H + 830°C/540°C Solution | Competitive Advantage | |--------------------|-----------------------------|------------------------| | **Certified Consistency** | H-grade guarantees narrow property ranges | Eliminates part-to-part variation in critical assemblies | | **Predictable Fatigue Life** | Consistent microstructure ensures uniform fatigue performance | Enables accurate life prediction and maintenance scheduling | | **Optimal Wear/Toughness Balance** | 540°C temper maximizes toughness at 38-43 HRC | Withstands moderate impact without excessive wear | | **Quality Documentation** | Full certification package with hardenability data | Simplifies compliance with industry standards (IATF 16949, AS9100) | | **Manufacturing Efficiency** | Predictable distortion and dimensional changes | Reduces finish machining costs and improves yield | ### **Component-Specific Performance Guarantees:** - **Gears:** Surface durability with consistent core properties batch-to-batch - **Shafts:** Uniform torsional strength throughout production runs - **Wear Parts:** Consistent abrasion resistance across all components - **Cutting Tools:** Predictable edge retention and resistance to chipping --- ## **4. International Standards & Specifications** ### **Property-Based & Process Specifications** This heat-treated condition is typically specified by **performance requirements** with reference to the heat treatment process. | Standard System | Designation / Reference | Application | |-----------------|-------------------------|-------------| | **SAE J1268** | Hardenability Bands | Foundation certification for H-grade material | | **ASTM A29/A29M** | Property Class | "Heat Treated" to specified hardness/strength ranges | | **AMS 2759/1** | Pyrometry | Governs temperature control requirements | | **CQI-9** | Heat Treat System Assessment | Automotive industry process control standard | | **Engineering Drawing** | **"Material: AISI 5150H, Heat Treat to 38-43 HRC"** | Common specification method | ### **International Material Equivalents** | Country/Region | Standard | Equivalent H-Grade | Comparable Heat Treated Condition | |----------------|----------|-------------------|-----------------------------------| | **Europe (EN)** | EN 10083-3 | **50Cr4+HH** | Quenched and tempered to 1100-1300 MPa tensile | | **Germany (DIN)** | DIN 17212 | **50Cr4H** | Condition **"+QT"** with hardness specification | | **Japan (JIS)** | JIS G4052 | **SCr445H** | Heat treated to equivalent mechanical properties | | **International (ISO)** | ISO 683-18 | **Type 1.7045** | With H-grade requirement specified | | **China (GB)** | GB/T 5216 | **50CrH** | Commonly used in quenched and tempered condition | ### **Heat Treatment Process Standards (Reference):** - **AMS 2759:** Pyrometry (Temperature Uniformity Surveys) - **ASTM A255:** Standard Test Methods for Determining Hardenability of Steel - **ISO 4885:** Heat treatments – Vocabulary - **NADCAP:** Aerospace heat treatment accreditation requirements --- ## **5. Manufacturing, Finishing & Service Considerations** ### **Post-Heat Treatment Processing:** * **Machining:** **Limited to abrasive methods**: * **Grinding:** Primary method for final dimensions * **Hard Turning:** Possible with CBN/PCBN tools for light finishing * **EDM:** Suitable for complex shapes * **Honing/Polishing:** For fine surface finishes * **Finishing Operations:** * **Shot Peening:** **Recommended** for fatigue-critical applications * **Surface Coatings:** * **Phosphate:** Corrosion protection and paint adhesion * **Black Oxide:** Cosmetic with mild corrosion resistance * **Hard Chrome:** Enhanced wear resistance on bearing surfaces * **Electroless Nickel:** Corrosion and wear resistance * **Joining:** * **Welding:** **Not recommended** after final heat treatment. If unavoidable: - Pre-heat to 300-350°C - Low-hydrogen electrodes only - Post-weld tempering at 540-560°C mandatory * **Mechanical Fastening:** Preferred method ### **Service Performance & Limitations:** * **Maximum Service Temperature:** **~300°C (570°F)** continuous. Gradual softening above this temperature. * **Corrosion Resistance:** **Poor.** Requires protective coatings for exposed service. * **Notch Sensitivity:** **Moderate** (q ≈ 0.80-0.85). Generous radii essential in high-stress areas. * **Fatigue Performance:** Excellent with proper surface finish and shot peening. ### **Quality Control for Heat Treated Components:** 1. **Hardness Verification:** 100% check on representative locations 2. **Microstructure Evaluation:** Sample verification of tempered martensite 3. **Surface Integrity:** NDT for cracks (MPI or LPI) 4. **Dimensional Verification:** Check for distortion within limits 5. **Mechanical Testing:** Batch testing from witness coupons --- ## **6. Design & Selection Guidelines** ### **Why Select This Exact Condition of AISI 5150H?** **When you need:** - **Certified consistency** in high-strength components - **Predictable performance** in demanding applications - **Optimal wear resistance** with **good toughness** - **Cost-effective alternative** to tool steels with certified properties - **Components** for automated, high-volume production ### **Alternative Heat Treatments for AISI 5150H:** | Tempering Temperature | Resulting Hardness (HRC) | Property Emphasis | |-----------------------|--------------------------|-------------------| | **200°C (390°F)** | 55-60 | Maximum Hardness/Wear | | **400°C (750°F)** | 48-53 | Very High Strength | | **540°C (1000°F)** | 38-43 | **Optimal Balance** | | **600°C (1110°F)** | 32-38 | High Toughness | ### **Comparison with Similar Materials:** | Material | Typical Hardness after similar HT | Relative Cost | Advantages vs. 5150H @ 540°C | |----------|-----------------------------------|---------------|------------------------------| | **4140H @ 540°C** | 35-40 | 90-95% | Better toughness, better weldability | | **4340H @ 540°C** | 38-43 | 120-130% | Superior toughness | | **5160H @ 540°C** | 40-45 | 105-110% | Higher hardness potential | | **O1 Tool Steel** | 58-62 | 150-200% | Much higher wear resistance | --- ## **Summary** **AISI 5150H steel, oil quenched from 830°C (1525°F) and tempered at 540°C (1000°F), represents the gold standard for certified, high-performance alloy steel components.** This specific combination delivers: 1. **Certified Consistency:** Guaranteed hardenability ensures mechanical properties within narrow, predictable ranges 2. **Optimal Property Balance:** 38-43 HRC provides ideal compromise between strength, toughness, and wear resistance 3. **Superior Performance:** 1100-1300 MPa tensile strength with good impact resistance 4. **Manufacturing Reliability:** Predictable response enables automated processing with minimal scrap **Final Service Condition:** This is a **ready-for-service state** for components machined before heat treatment, with final finishing limited to grinding and coating. **Ideal For:** - **Critical automotive components** requiring certified consistency - **Heavy machinery wear parts** subject to abrasion and impact - **Industrial cutting tools** requiring predictable performance - **Any application** where component failure has significant consequences **The H-grade certification combined with the 540°C tempering temperature provides engineers with a material solution that eliminates uncertainty,** enabling designs that maximize performance while maintaining reliability. This heat-treated condition offers tool steel-like performance with certified consistency at alloy steel cost, delivering exceptional value for demanding industrial applications. -:- For detailed product information, please contact sales. -: AISI 5150H Steel, oil quenched from 830°C (1525°F), 540°C (1000°F) temper Specification Dimensions Size： Diameter 20-1000 mm Length <6300 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 5150H Steel, oil quenched from 830°C (1525°F), 540°C (1000°F) temper Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 5150H Steel, oil quenched from 830°C (1525°F), 540°C (1000°F) temper -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 5150H Steel, oil quenched from 830°C (1525°F), 540°C (1000°F) temper -:- For detailed product information, please contact sales. -:

Packing of AISI 5150H Steel, oil quenched from 830°C (1525°F), 540°C (1000°F) temper -:- 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 2771 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