AISI 5150 Steel, oil quenched

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

AISI 5150 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 5150 Steel, Heat Treated to 830°C Oil Quenched + 540°C Tempered Condition** ## **Executive Summary** **AISI 5150 steel, oil quenched from 830°C (1525°F) and tempered at 540°C (1000°F),** represents this medium-high carbon chromium steel in its **peak engineered condition**, achieving an exceptional balance of strength, toughness, and wear resistance. This specific heat treatment regimen transforms the steel into a **tempered martensitic microstructure** that delivers outstanding mechanical properties for demanding applications. The 540°C (1000°F) tempering temperature falls within the **secondary hardening range** for chromium steels, optimizing the precipitation of fine alloy carbides to achieve an ideal compromise between hardness (~38-43 HRC) and impact toughness. This condition is particularly valued for components subjected to **heavy dynamic loading, impact, and wear** in construction, mining, heavy machinery, and tooling applications. --- ## **1. Chemical Composition & Metallurgical Response** The chemical composition enables AISI 5150 to respond optimally to this specific heat treatment, with each element playing a critical role in achieving the final properties. | Element | Composition Range (%) | Typical Value (%) | Role in Achieving 830°C OQ + 540°C Temper Properties | |---------|----------------------|-------------------|------------------------------------------------------| | **Carbon (C)** | 0.48 - 0.53 | 0.50 | **Foundation of strength.** At 0.50%, ensures near-complete martensite formation during 830°C oil quench (as-quenched hardness ~56-60 HRC). During 540°C temper, enables precipitation of fine epsilon carbides while maintaining substantial hardness. | | **Manganese (Mn)** | 0.70 - 0.90 | 0.80 | **Hardenability enhancer.** Ensures sufficient hardenability for oil quenching from 830°C, particularly important for achieving uniform properties in moderate sections. | | **Chromium (Cr)** | 0.70 - 0.90 | 0.80 | **Critical for tempering response.** Promotes **significant secondary hardening** at 540°C through formation of chromium carbides (Cr₇C₃, Cr₂₃C₆). These fine precipitates provide exceptional tempering resistance and contribute substantially to the 38-43 HRC final hardness. | | **Silicon (Si)** | 0.15 - 0.35 | 0.25 | **Solid solution strengthener & tempering stabilizer.** Raises the tempering curve, helping maintain strength at 540°C. Also provides some resistance to temper embrittlement. | | **Sulfur (S)** | ≤ 0.040 | 0.025 | **Machinability aid in pre-hard state.** Typically controlled at moderate levels to improve chip formation during machining before final heat treatment. | | **Phosphorus (P)** | ≤ 0.035 | 0.020 | **Residual element.** Kept low to minimize temper embrittlement susceptibility, particularly important when tempering at 540°C. | **Metallurgical Transformation Pathway:** 1. **830°C Austenitizing:** Complete dissolution of carbides, formation of homogeneous austenite 2. **Oil Quenching:** Transformation to high-carbon martensite with some retained austenite 3. **540°C Tempering:** - Precipitation of fine transition carbides (ε-carbide) - Formation of alloy carbides (chromium carbides) - Recovery of martensitic structure - Significant stress relief 4. **Final Structure:** **Tempered lath martensite** with uniform dispersion of **fine alloy carbides** (50-200 nm) **Key Metallurgical Features:** - **As-quenched hardness:** ~56-60 HRC (depending on exact carbon content) - **Tempering response:** Significant secondary hardening effect due to chromium - **Carbide precipitation:** Optimal at 540°C for balancing hardness and toughness - **Retained austenite:** Minimal (<5%) due to high tempering temperature --- ## **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** | Increased compared to annealed state due to martensitic structure | | **Shear Modulus (G)** | 80 - 83 GPa | - | | **Poisson's Ratio** | 0.29 | - | | **Thermal Conductivity** | 41 - 45 W/m·K | Reduced compared to annealed due to lattice strain | | **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 due to microstructural defects | ### **Mechanical Properties (830°C OQ + 540°C Temper)** *These properties represent the guaranteed or typical minimums achievable with this specific heat treatment.* | Property | Typical / Minimum Range | Significance for Design & Application | |----------|-------------------------|----------------------------------------| | **Hardness** | **363 - 444 HB** / **38 - 43 HRC** | **Optimal service hardness.** Provides excellent wear resistance while maintaining good impact toughness. The 540°C temper specifically targets this hardness range for maximum service performance. | | **Tensile Strength** | **1100 - 1300 MPa** (160 - 188 ksi) | **High strength level.** Approximately 10-15% higher than similarly treated 5140 due to higher carbon content. | | **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. Demonstrates effectiveness of 540°C temper in restoring ductility. | | **Reduction of Area** | **40 - 50%** | Good micro-ductility. Typically 40-45% at this hardness level. | | **Charpy V-Notch Impact Energy** | **30 - 45 J** (at 20°C) | **Good impact toughness** considering the high hardness. The 540°C temper maximizes toughness within this hardness range. | | **Fatigue Strength (Rotating Bending, R=-1)** | **~500 - 550 MPa** | High endurance limit (~0.42-0.45 of tensile strength). Critical for dynamically loaded components. | | **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:** 1. **Austenitizing (830°C / 1525°F):** - **Purpose:** Achieve complete austenitization with minimal grain growth - **Temperature Selection:** 830°C is optimal for AISI 5150 - high enough for complete carbide dissolution but low enough to minimize grain growth - **Soak Time:** 20-30 minutes per inch of thickness minimum - **Atmosphere:** Protective atmosphere recommended to prevent decarburization 2. **Quenching (Oil):** - **Medium:** Fast oil quench (ISO VG 68 or equivalent, 40-60°C) - **Critical:** Sufficient agitation to ensure uniform cooling - **As-Quenched Hardness:** 56-60 HRC (dependent on exact carbon content) - **Section Size Capability:** Through-hardens up to 50-75mm diameter effectively 3. **Tempering (540°C / 1000°F):** - **Purpose:** Achieve optimal strength-toughness balance in the secondary hardening range - **Time:** 1.5-2.5 hours per inch of thickness - **Cooling:** Air cool after tempering (rapid cooling recommended to minimize temper embrittlement) - **Double Tempering:** Often beneficial to ensure complete transformation and stress relief **Temperature Rationale:** - **830°C Austenitizing:** Lower than typical 850°C+ for alloy steels, but sufficient for AISI 5150 while reducing distortion risk - **540°C Tempering:** Falls within secondary hardening range for chromium steels, maximizing toughness retention at high hardness --- ## **3. Product Applications (In This Heat Treated Condition)** This is the **final, ready-for-service condition** for high-performance components requiring exceptional strength, wear resistance, and moderate toughness. ### **Critical Application Sectors:** **Heavy Machinery & Construction Equipment:** - **Excavator & Loader Components:** Bucket teeth adapters, cutting edges, pivot pins, linkage components - **Crane & Hoist Components:** Hook blocks, sheave pins, boom connection pins - **Bulldozer & Grader Parts:** Cutting blades, moldboard edges, scarifier teeth - **Mining Equipment:** Drill bits, crusher jaws, hammer mill hammers, shovel teeth **Agricultural Machinery:** - **Tillage Tools:** Plow shares, chisel points, disc blades - **Harvesting Components:** Combine cutter bars, chopper knives, hammer mill beaters - **Implement Parts:** Heavy-duty hitch pins, drawbar components, PTO shafts **Industrial Manufacturing:** - **Forging & Stamping Dies:** For non-ferrous metals and lower-strength steels - **Machine Tool Components:** Lathe centers, arbors, heavy-duty tool holders - **Material Handling:** Conveyor system components subject to abrasive wear - **Pump & Valve Components:** Shafts, sleeves, valve stems for abrasive service **Transportation & Automotive:** - **Heavy Truck Components:** Fifth wheel components, suspension pins, brake camshafts - **Off-Road Vehicle Parts:** Axle shafts, drive train components, suspension members - **Railroad Components:** Coupler parts, draft gear components, brake shoes **Tooling & Cutting Applications:** - **Industrial Knives:** Slitter knives, shear blades, cutting blades - **Woodworking Tools:** Chipper knives, planer knives, debarker tools - **Paper Industry:** Slitter blades, cutter bars, creaser rules ### **Why This Specific Heat Treatment on AISI 5150?** | Design Requirement | 5150 + 830°C/540°C Solution | Competitive Advantage | |--------------------|-----------------------------|------------------------| | **High Wear Resistance** | 38-43 HRC provides excellent abrasion resistance | Superior to lower hardness steels in abrasive environments | | **Impact Resistance** | 540°C temper maximizes toughness at this hardness | Can withstand moderate impact without brittle fracture | | **Fatigue Performance** | Tempered martensite structure with fine carbides | Good resistance to cyclic loading in demanding applications | | **Cost-Effectiveness** | Lower cost than tool steels with similar hardness | Provides tool steel performance at alloy steel cost | | **Machinability (pre-HT)** | Good machinability in annealed/normalized state | Complex shapes can be machined before final heat treatment | ### **Component-Specific Performance:** - **Wear Parts:** Surface hardness provides excellent resistance to abrasive wear - **Impact Tools:** Good toughness prevents chipping and fracture under impact - **Cutting Edges:** Hardness sufficient for cutting non-ferrous materials and softer steels - **Structural Components:** High strength-to-weight ratio for load-bearing applications --- ## **4. International Standards & Specifications** ### **Property-Based & Process Specifications** This heat-treated condition is typically specified by **performance requirements** on engineering drawings, with the 830°C OQ + 540°C temper being the proven method to achieve them. | Standard System | Designation / Reference | Application to This Condition | |-----------------|-------------------------|-------------------------------| | **ASTM A29/A29M** | Property Class | Would be supplied as "Heat Treated" to specified hardness/strength ranges | | **SAE J404** | Chemical Composition | Defines base material chemistry | | **AMS 2759/1** | Pyrometry | Governs temperature control requirements for heat treating | | **Engineering Drawing** | **"Material: AISI 5150, Heat Treat to 38-43 HRC"** | Most common specification method | | **Customer Specifications** | Various | Often include specific heat treatment parameters | ### **International Material Equivalents (Can be heat treated to similar properties):** | Country/Region | Standard | Equivalent Grade | Comparable Heat Treated Condition | |----------------|----------|-------------------|-----------------------------------| | **Europe (EN)** | EN 10083-3 | **50Cr4** | Can be quenched and tempered to 1100-1300 MPa tensile strength | | **Germany (DIN)** | DIN 17212 | **50Cr4** | Condition **"+QT"** to specified hardness | | **Japan (JIS)** | JIS G4105 | **SCr445** | Heat treated to equivalent mechanical properties | | **International (ISO)** | ISO 683-18 | **Type 1.7045** | Similar properties achievable | | **China (GB)** | GB/T 3077 | **50Cr** | 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 - **CQI-9:** Heat Treat System Assessment (Automotive industry) --- ## **5. Manufacturing, Finishing & Service Considerations** ### **Post-Heat Treatment Processing:** * **Machining:** **Limited options** after heat treatment: * **Grinding:** Primary method for achieving final dimensions * **Hard Turning:** Possible with CBN/PCBN tools for light finishing cuts * **Electrical Discharge Machining (EDM):** Suitable for complex shapes * **Honing/Polishing:** For fine surface finishes on bearing surfaces * **Finishing Operations:** * **Shot Peening:** **Highly beneficial** for fatigue-critical applications * **Surface Coatings:** * **Phosphate Coating:** For corrosion protection and paint adhesion * **Black Oxide:** Cosmetic finish with mild corrosion resistance * **Hard Chrome Plating:** For enhanced wear resistance on bearing surfaces * **Thermal Spray Coatings:** For extreme wear applications * **Joining:** * **Welding:** **Generally not recommended** after final heat treatment. If absolutely necessary: - Pre-heat to 300-350°C required - Use low-hydrogen electrodes exclusively - Post-weld tempering at 540-560°C mandatory - Significant property degradation in HAZ expected * **Mechanical Fastening:** Preferred joining method for heat-treated components ### **Service Performance & Limitations:** * **Maximum Service Temperature:** **~300°C (570°F)** continuous exposure. Above this, overtempering occurs with gradual softening. * **Corrosion Resistance:** **Poor** (similar to plain carbon steels). Requires protective coatings for exposed service. * **Notch Sensitivity:** **Moderate to high** (notch sensitivity factor q ≈ 0.80-0.85). Generous radii essential in high-stress areas. * **Fatigue Performance:** Excellent with proper surface finish (ground < 1.6 μm Ra) and shot peening. * **Wear Characteristics:** Excellent abrasion resistance, good adhesive wear resistance. ### **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:** Magnetic particle or liquid penetrant inspection for cracks 4. **Dimensional Verification:** Check for distortion within acceptable limits 5. **Mechanical Testing:** Batch testing from witness coupons --- ## **6. Design & Selection Guidelines** ### **Why Select This Exact Condition of AISI 5150?** **When you need:** - **High strength** combined with **good wear resistance** - **Moderate toughness** at relatively high hardness - **Cost-effective alternative** to tool steels for many applications - **Predictable performance** in demanding service conditions - **Components** that can be machined before final heat treatment ### **Alternative Heat Treatments for AISI 5150 (for comparison):** | Tempering Temperature | Resulting Hardness (HRC) | Property Emphasis | Compared to 540°C Temper | |-----------------------|--------------------------|-------------------|---------------------------| | **200°C (390°F)** | 55-60 | Maximum Hardness/Wear | Higher wear resistance but very low toughness (5-15 J impact) | | **400°C (750°F)** | 48-53 | Very High Strength | Higher strength but lower toughness (20-30 J impact) | | **540°C (1000°F)** | 38-43 | **Optimal Balance** | **Best combination for most demanding applications** | | **600°C (1110°F)** | 32-38 | High Toughness | Higher toughness but lower strength and wear resistance | ### **Comparison with Similar Materials:** | Material | Typical Hardness (HRC) after similar HT | Relative Cost | Advantages vs. 5150 @ 540°C temper | |----------|----------------------------------------|---------------|-------------------------------------| | **4140 @ 540°C** | 35-40 | 90-95% | Better toughness, better weldability | | **4340 @ 540°C** | 38-43 | 120-130% | Superior toughness, better hardenability | | **5160 @ 540°C** | 40-45 | 105-110% | Higher hardness potential, better spring properties | | **O1 Tool Steel** | 58-62 (different HT) | 150-200% | Much higher wear resistance, better dimensional stability | ### **Design Considerations:** - **Section Size:** Optimal for sections up to 75mm diameter - **Stress Concentrations:** Use generous radii (minimum 3mm) - **Surface Finish:** Critical for fatigue performance - **Heat Treatment Planning:** Account for dimensional changes (typical 0.1-0.3%) - **Corrosion Protection:** Essential for exposed applications --- ## **7. Economic & Performance Considerations** ### **Cost-Benefit Analysis:** **Compared to Through-Hardened Tool Steels:** - **Material Cost:** 50-70% of equivalent tool steels - **Machining Cost:** Lower in annealed/normalized state - **Heat Treatment Cost:** Similar or slightly lower - **Tool Life:** Comparable in service for many applications - **Total Cost:** Typically 60-80% of tool steel alternatives **Total Cost of Ownership Factors:** 1. **Initial Cost:** Lower than tool steels 2. **Manufacturing Cost:** Lower due to better machinability before heat treatment 3. **Service Life:** Excellent for many applications, though may be shorter than premium tool steels in extreme wear applications 4. **Replacement Cost:** Lower due to material cost advantage ### **Performance Trade-offs:** **Advantages over lower-carbon steels (e.g., 4140):** - Higher wear resistance - Higher strength potential - Better retention of hardness at moderate temperatures **Limitations compared to lower-carbon steels:** - Lower toughness - Greater susceptibility to brittle fracture - More challenging to weld - Greater distortion during heat treatment --- ## **Summary** **AISI 5150 steel, oil quenched from 830°C (1525°F) and tempered at 540°C (1000°F), represents an optimal heat treatment regimen** that unlocks the full potential of this medium-high carbon chromium steel. This specific combination delivers: 1. **Exceptional Strength:** 1100-1300 MPa tensile strength with high yield strength 2. **Good Wear Resistance:** 38-43 HRC hardness provides excellent abrasion resistance 3. **Balanced Toughness:** 30-45 J Charpy impact energy for the hardness level 4. **Cost-Effective Performance:** Tool steel-like properties at alloy steel cost **Final Service Condition:** This is a **ready-for-service state** for components that have been completely machined before heat treatment. Final finishing is typically limited to grinding, polishing, and protective coating. **Ideal For:** - **Heavy machinery wear parts** subject to abrasion and impact - **Industrial cutting tools** for non-ferrous materials and softer steels - **Agricultural tillage tools** requiring wear resistance and some toughness - **Mining equipment components** subjected to abrasive wear - **Any application** where the combination of high strength, good wear resistance, and moderate toughness is required at reasonable cost **The 830°C austenitizing temperature is specifically chosen for AISI 5150** to minimize distortion while ensuring complete austenitization, and the **540°C tempering temperature maximizes toughness** while retaining substantial hardness through chromium's secondary hardening effect. This heat-treated condition provides engineers with a **versatile, cost-effective material solution** for demanding applications where tool steels would be over-engineered and lower-carbon steels would be inadequate. It represents an excellent balance of performance, manufacturability, and cost for a wide range of industrial applications. -:- For detailed product information, please contact sales. -: AISI 5150 Steel, oil quenched from 830°C (1525°F), 540°C (1000°F) temper Specification Dimensions Size： Diameter 20-1000 mm Length <6297 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 5150 Steel, oil quenched from 830°C (1525°F), 540°C (1000°F) temper Properties -:- For detailed product information, please contact sales. -:

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

Packing of AISI 5150 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 2768 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