41CrAlMo7 40CAD6.12 905M31 DIN 1.8509 EN41B Nitriding Steel
41CrAlMo7 40CAD6.12 905M31 DIN1.8509 EN41B Nitriding Steel
Product Description
FUSHUN METAL’s 41CrAlMo7-10 Steel is a premium chromium-aluminum-molybdenum nitriding steel offering an exceptional combination of high core strength, excellent nitriding response, good toughness, and superior wear resistance in nitrided condition. With a carefully engineered chemical composition featuring optimized levels of aluminum (0.7-1.0%), chromium (1.5-1.8%), and molybdenum (0.25-0.35%), our 41CrAlMo7-10 delivers outstanding performance in demanding applications requiring both high surface hardness and good core strength. Available in multiple forms including round bars, flat bars, plates, forgings, and custom shapes, this versatile steel is ideal for applications in heavy-duty gears, camshafts, crankshafts, highly stressed machine components, forming and punching tools, and other applications where both wear resistance and fatigue strength are essential. The aluminum content enables the formation of extremely hard aluminum nitrides during nitriding, producing surface hardness up to 1000-1100 HV without requiring conventional quench and temper heat treatment. Each product undergoes comprehensive quality control to ensure consistent properties, precise dimensions, and superior surface quality for reliable performance in critical industrial applications.
Equivalent Steel Grades
41CrAlMo7-10 is part of a family of nitriding steels with the following equivalent grades in different standards:
| Standard | Designation | Comparable Grades |
|---|---|---|
| EN | 41CrAlMo7-10 | 31CrAlMo7-10, 34CrAlMo5-10, 34CrAlNi7-10 |
| DIN | 1.8509 | 1.8506 (31CrAlMo7-10), 1.8507 (34CrAlMo5-10), 1.8550 (34CrAlNi7-10) |
| AISI/SAE | Similar to 8620H (modified) | Nitralloy N, Nitralloy 135M |
| British BS | 905M39 | 722M24, EN41B |
| Japanese JIS | SACM645 | SACM645, SACM940 |
| Chinese GB | 38CrAlMo | 40CrAlMo, 38CrMoAl |
| Russian GOST | 38KH2MYuA | 38KH2MYUA, 38KH2MYuA |
| Italian UNI | 40CrAlMo7-10 | 38CrAlMo7-10 |
Available Product Forms and Dimensions
FUSHUN METAL offers 41CrAlMo7-10 Nitriding Steel in a wide range of forms to meet diverse application requirements:
Round Bar Specifications
| Diameter (mm) | Standard Length (mm) | Tolerance | Surface Condition |
|---|---|---|---|
| 10 – 30 | 3000, 6000, Fixed or Random | h9, h10, h11, k12 | Black, Peeled, Turned, Ground, Polished |
| 32 – 80 | 3000, 6000, Fixed or Random | h9, h10, h11, k12 | Black, Peeled, Turned, Ground, Polished |
| 85 – 150 | 3000, 6000, Fixed or Random | h9, h10, h11, k12 | Black, Peeled, Turned, Ground |
| 160 – 300 | 2000, 3000, Fixed or Random | h10, h11, k12 | Black, Peeled, Turned, Rough Ground |
| 320 – 500 | 1000, 2000, Fixed or Random | h11, k12 | Black, Peeled, Turned |
| 550 – 800 | 1000, Fixed or Random | k12, k13 | Black, Rough Turned |
Flat Bar Specifications
| Thickness (mm) | Width (mm) | Standard Length (mm) | Tolerance | Surface Condition |
|---|---|---|---|---|
| 5 – 15 | 20 – 100 | 3000, 6000, Fixed or Random | EN 10278, EN 10058 | Hot Rolled, Cold Drawn, Ground |
| 16 – 30 | 30 – 150 | 3000, 6000, Fixed or Random | EN 10278, EN 10058 | Hot Rolled, Cold Drawn, Ground |
| 32 – 50 | 40 – 200 | 3000, 6000, Fixed or Random | EN 10058 | Hot Rolled, Cold Drawn, Ground |
| 55 – 80 | 60 – 300 | 3000, 6000, Fixed or Random | EN 10058 | Hot Rolled, Cold Drawn |
| 85 – 120 | 80 – 400 | 3000, Fixed or Random | EN 10058 | Hot Rolled |
| 125 – 200 | 100 – 500 | 2000, 3000, Fixed or Random | EN 10058 | Hot Rolled |
Plate Specifications
| Thickness (mm) | Width (mm) | Length (mm) | Tolerance | Surface Condition |
|---|---|---|---|---|
| 5 – 10 | Up to 2000 | Up to 6000 | EN 10029, ASTM A6 | Hot Rolled, Pickled, Ground |
| 12 – 25 | Up to 2500 | Up to 8000 | EN 10029, ASTM A6 | Hot Rolled, Pickled, Ground |
| 30 – 60 | Up to 2500 | Up to 10000 | EN 10029, ASTM A6 | Hot Rolled, Pickled |
| 65 – 100 | Up to 2200 | Up to 8000 | EN 10029, ASTM A6 | Hot Rolled |
| 110 – 200 | Up to 2000 | Up to 6000 | EN 10029, ASTM A6 | Hot Rolled |
| 220 – 300 | Up to 1800 | Up to 4000 | EN 10029, ASTM A6 | Hot Rolled |
Square Bar Specifications
| Size (mm) | Standard Length (mm) | Tolerance | Surface Condition |
|---|---|---|---|
| 10 x 10 – 30 x 30 | 3000, 6000, Fixed or Random | h11, h12, k12 | Hot Rolled, Cold Drawn, Ground |
| 35 x 35 – 80 x 80 | 3000, 6000, Fixed or Random | h11, h12, k12 | Hot Rolled, Cold Drawn, Ground |
| 85 x 85 – 150 x 150 | 3000, 6000, Fixed or Random | h12, k12 | Hot Rolled, Ground |
| 160 x 160 – 300 x 300 | 2000, 3000, Fixed or Random | k12, k13 | Hot Rolled |
Hexagonal Bar Specifications
| Size (mm) | Standard Length (mm) | Tolerance | Surface Condition |
|---|---|---|---|
| 10 – 30 (across flats) | 3000, 6000, Fixed or Random | h11, h12 | Hot Rolled, Cold Drawn, Ground |
| 32 – 60 (across flats) | 3000, 6000, Fixed or Random | h11, h12 | Hot Rolled, Cold Drawn, Ground |
| 65 – 100 (across flats) | 3000, Fixed or Random | h12, k12 | Hot Rolled, Cold Drawn |
Forged Block Specifications
| Thickness (mm) | Width (mm) | Length (mm) | Tolerance | Surface Condition |
|---|---|---|---|---|
| 50 – 200 | 100 – 600 | 200 – 1000 | DIN 7527, ASTM A711 | Black, Rough Machined |
| 220 – 400 | 250 – 800 | 300 – 1500 | DIN 7527, ASTM A711 | Black, Rough Machined |
| 420 – 600 | 350 – 1000 | 400 – 2000 | DIN 7527, ASTM A711 | Black, Rough Machined |
Forged Round Specifications
| Diameter (mm) | Length (mm) | Tolerance | Surface Condition |
|---|---|---|---|
| 150 – 300 | 200 – 1000 | DIN 7527, ASTM A711 | Black, Rough Machined |
| 320 – 500 | 300 – 1500 | DIN 7527, ASTM A711 | Black, Rough Machined |
| 550 – 800 | 400 – 2000 | DIN 7527, ASTM A711 | Black, Rough Machined |
| 850 – 1200 | 500 – 1500 | DIN 7527, ASTM A711 | Black, Rough Machined |
Special Shapes and Custom Dimensions
FUSHUN METAL also offers 41CrAlMo7-10 in custom shapes, sizes, and pre-machined conditions to meet specific application requirements:
- Near-net shape forgings
- Pre-machined gear blanks
- Camshaft and crankshaft blanks
- Hollow bar and tubes
- Custom profile sections
- Semi-finished components
- Pre-machined tool blanks
- Custom forged shapes per drawing
Chemical Composition
FUSHUN METAL’s 41CrAlMo7-10 Steel features the following nominal composition per EN 10085 standard:
| Element | Content (%) |
|---|---|
| Carbon (C) | 0.38-0.45% |
| Silicon (Si) | 0.40% max |
| Manganese (Mn) | 0.40-0.70% |
| Phosphorus (P) | 0.025% max |
| Sulfur (S) | 0.035% max |
| Chromium (Cr) | 1.50-1.80% |
| Molybdenum (Mo) | 0.25-0.35% |
| Aluminum (Al) | 0.70-1.00% |
| Iron (Fe) | Balance |
Key Element Functions
- Carbon (0.38-0.45%): Provides moderate core hardness and strength after heat treatment. The carbon content is optimized to provide good core properties while maintaining excellent nitriding response.
- Chromium (1.50-1.80%): Enhances hardenability and contributes to the formation of chromium nitrides during nitriding, improving surface hardness and wear resistance.
- Aluminum (0.70-1.00%): A key alloying element that forms extremely hard aluminum nitrides during the nitriding process, enabling exceptional surface hardness (up to 1100 HV) and nitride case depth.
- Molybdenum (0.25-0.35%): Improves hardenability, enhances core strength, and helps maintain toughness. Also contributes to high-temperature strength and creep resistance.
- Manganese (0.40-0.70%): Improves hardenability and contributes to overall strength.
- Silicon (max 0.40%): Contributes to strength and deoxidation during steelmaking.
Physical and Mechanical Properties
Our 41CrAlMo7-10 Steel offers an impressive combination of physical and mechanical properties that make it ideal for demanding applications:
Physical Properties
| Property | Units | Value |
|---|---|---|
| Density | g/cm³ | 7.85 |
| Melting Range | °C | 1420-1460 |
| Thermal Conductivity (20°C) | W/m·K | 42 |
| Specific Heat Capacity | J/kg·K | 470 |
| Electrical Resistivity | Ω·mm²/m | 0.22 |
| Modulus of Elasticity (20°C) | GPa | 210 |
| Coefficient of Thermal Expansion (20-100°C) | 10⁻⁶/K | 12.5 |
| Coefficient of Thermal Expansion (20-300°C) | 10⁻⁶/K | 13.5 |
Mechanical Properties (Quenched and Tempered Condition – Before Nitriding)
| Property | Value |
|---|---|
| Core Hardness | 28-34 HRC (285-340 HB) |
| Tensile Strength | 950-1150 MPa |
| Yield Strength | 750-900 MPa |
| Elongation | 10-14% |
| Reduction of Area | 40-50% |
| Impact Strength (Charpy V-notch) | 40-60 J |
Nitriding Properties
| Property | Value |
|---|---|
| Surface Hardness After Gas Nitriding | 950-1100 HV0.5 |
| Surface Hardness After Plasma Nitriding | 900-1050 HV0.5 |
| Effective Case Depth (550 HV) | 0.3-0.7 mm (depending on nitriding time and temperature) |
| Compound Layer Thickness | 10-20 µm (controllable) |
| Fatigue Strength Improvement | 30-50% compared to untreated condition |
| Wear Resistance Improvement | Up to 10 times compared to untreated condition |
Applications
FUSHUN METAL’s 41CrAlMo7-10 Nitriding Steel is specifically engineered for applications requiring an optimal combination of high surface hardness, good core strength, and excellent wear resistance:
Automotive Applications
- Camshafts and camshaft lobes
- Crankshafts for high-performance engines
- Transmission gears and shafts
- Differential gears
- Steering components
- Piston pins
- Valve components
- Engine timing gears
Industrial Machinery Applications
- Heavy-duty industrial gears
- Worm gears and shafts
- Extrusion screws
- Spindles and arbors
- Hydraulic cylinders and rods
- Drive shafts for high-load applications
- Pump components
- Compressor components
Tool and Die Applications
- Forming dies
- Cold extrusion tooling
- Punches and die inserts
- Gauges and fixtures
- Plastic molding components
- Press tooling
- Forging dies
- Cutting tools for moderate service
Heavy Equipment Applications
- Earthmoving equipment components
- Mining machinery parts
- Agricultural equipment components
- Construction machinery parts
- Gears for heavy equipment
- Bearing races and rollers
- High-stress pins and bushings
- Hydraulic system components
Other Specialized Applications
- Aircraft landing gear components
- Turbine and compressor parts
- Heavy-duty bearing components
- Railroad equipment parts
- Marine propulsion system components
- Oil and gas industry components
- Defense industry applications
- Power generation equipment
Heat Treatment Recommendations
For customers performing their own heat treatment of 41CrAlMo7-10 steel, FUSHUN METAL recommends the following parameters:
Stress Relieving
- Heat slowly to 600-650°C (1110-1200°F)
- Hold for minimum 2 hours per 25mm of thickness
- Cool slowly in furnace to below 500°C (930°F), then air cool
- Recommended before extensive machining to minimize distortion
Normalizing
- Heat to 880-920°C (1615-1690°F)
- Hold for 15-30 minutes after thorough heating
- Cool in still air
- Resulting hardness: 250-300 HB
Hardening (Pre-Nitriding)
- Preheat: 550-650°C (1020-1200°F)
- Austenitizing: 840-880°C (1545-1615°F)
- Holding time: 15-45 minutes after thorough heating (depending on section size)
- Quenching: Oil or polymer quench
- Achievable hardness after quenching: 48-52 HRC
Tempering (Pre-Nitriding)
- Temper immediately after quenching
- Tempering temperature: 600-680°C (1110-1255°F) for best nitriding response
- Holding time: 1-2 hours per 25mm of thickness (minimum 2 hours)
- Cooling: Air cooling
- Resulting core hardness: 28-34 HRC (285-340 HB)
Nitriding
- Pre-cleaning: Thorough cleaning to remove oils, oxides, and contaminants
- Gas Nitriding:
- Single-stage process: 490-530°C (915-985°F) for 40-100 hours (depending on required case depth)
- Two-stage (Floe) process:
- Stage 1: 500-525°C (930-975°F) with 30-40% dissociation for 5-15 hours
- Stage 2: 550-565°C (1020-1050°F) with 75-85% dissociation for 5-95 hours (depending on required case depth)
- Plasma Nitriding:
- Temperature: 480-530°C (895-985°F)
- Time: 10-50 hours (depending on required case depth)
- Gas mixture: N₂:H₂ ratio 1:3 to 3:1 (depending on required layer composition)
- Salt Bath Nitriding:
- Temperature: 570-590°C (1060-1095°F)
- Time: 1-3 hours
- Achievable surface hardness: 950-1100 HV0.5
- Typical case depth: 0.3-0.7 mm (depending on process and time)
Post-Nitriding Treatment (Optional)
- Post-oxidation: 350-400°C (660-750°F) for 20-60 minutes for improved corrosion resistance
- Fine Lapping or Polishing: Light polishing to improve surface finish after nitriding
- Low-temperature tempering: 150-200°C (300-390°F) for stress relief after nitriding
Machining Recommendations
To achieve optimal results when machining 41CrAlMo7-10 steel, FUSHUN METAL recommends the following parameters:
Condition: Annealed (200-250 HB)
| Operation | Tool Material | Cutting Speed | Feed Rate | Depth of Cut | Coolant |
|---|---|---|---|---|---|
| Turning | Cemented Carbide P20-P30 | 120-150 m/min | 0.2-0.4 mm/rev | 2-5 mm | Yes |
| Turning | High Speed Steel | 25-35 m/min | 0.1-0.3 mm/rev | 1-3 mm | Yes |
| Milling | Cemented Carbide P20-P40 | 100-130 m/min | 0.1-0.3 mm/tooth | 2-6 mm | Yes |
| Milling | High Speed Steel | 20-30 m/min | 0.05-0.2 mm/tooth | 1-4 mm | Yes |
| Drilling | High Speed Steel | 20-25 m/min | 0.05-0.15 mm/rev | – | Yes |
| Drilling | Cemented Carbide | 80-100 m/min | 0.1-0.2 mm/rev | – | Yes |
| Grinding | Silicon Carbide Wheel | 25-30 m/sec | – | 0.005-0.05 mm | Yes |
Condition: Quenched and Tempered (30-34 HRC)
| Operation | Tool Material | Cutting Speed | Feed Rate | Depth of Cut | Coolant |
|---|---|---|---|---|---|
| Turning | Cemented Carbide P10-P20 | 100-130 m/min | 0.15-0.3 mm/rev | 1-3 mm | Yes |
| Turning | High Speed Steel | 15-25 m/min | 0.1-0.2 mm/rev | 0.5-2 mm | Yes |
| Milling | Cemented Carbide P10-P30 | 80-110 m/min | 0.1-0.25 mm/tooth | 1-4 mm | Yes |
| Milling | High Speed Steel | 15-22 m/min | 0.05-0.15 mm/tooth | 0.5-3 mm | Yes |
| Drilling | High Speed Steel | 15-20 m/min | 0.05-0.12 mm/rev | – | Yes |
| Drilling | Cemented Carbide | 60-80 m/min | 0.08-0.15 mm/rev | – | Yes |
| Grinding | Aluminum Oxide Wheel | 25-30 m/sec | – | 0.005-0.03 mm | Yes |
Post-Nitriding Machining
After nitriding, only grinding, honing, lapping, or superfinishing operations are recommended:
| Operation | Wheel/Stone Type | Speed | Feed | Depth | Coolant |
|---|---|---|---|---|---|
| Grinding | Aluminum Oxide (Fine) | 20-25 m/sec | 0.5-1.0 m/min | 0.005-0.01 mm | Abundant |
| Honing | Diamond or CBN Stone | 15-25 m/min | – | 0.002-0.005 mm | Honing Oil |
| Lapping | Cast Iron Lap with Diamond Paste | 10-20 m/min | – | 0.001-0.003 mm | Lapping Oil |
| Superfinishing | Fine Abrasive Stone | 5-10 m/min | – | 0.001 mm | Light Oil |
Welding Recommendations
Welding of 41CrAlMo7-10 is challenging due to its alloying elements but possible with proper precautions:
- Preheat: 250-350°C (480-660°F)
- Interpass Temperature: 250-400°C (480-750°F)
- Post-weld Heat Treatment: Recommended – slow cooling followed by tempering at 600-650°C (1110-1200°F)
- Filler Materials: Low hydrogen electrodes with similar composition (preferably CrMo type)
- Processes: TIG/GTAW or MMA/SMAW with low hydrogen electrodes
- Special Considerations: After welding, the nitriding properties in the weld area will be altered
- Limitations: For repair purposes only; structural welds not recommended
- Alternative: Consider mechanical joining methods when possible
Comparative Advantages over Other Similar Grades
Understanding how 41CrAlMo7-10 steel compares to similar grades helps in selecting the optimal material for your application:
| Property | 41CrAlMo7-10 | 34CrAlMo5-10 | 34CrAlNi7-10 | 31CrMoV9 | 42CrMo4 |
|---|---|---|---|---|---|
| Aluminum Content | 0.7-1.0% | 0.8-1.2% | 0.8-1.2% | None | None |
| Core Strength | Very Good | Good | Very Good | Good | Excellent |
| Nitriding Response | Excellent | Excellent | Excellent | Good | Moderate |
| Case Hardness | 950-1100 HV | 950-1100 HV | 950-1100 HV | 850-950 HV | 700-850 HV |
| Toughness | Very Good | Good | Excellent | Very Good | Excellent |
| Machinability | Good | Good | Good | Very Good | Very Good |
| Cost | Moderate-High | Moderate | High | Moderate | Moderate-Low |
| Typical Applications | Heavy-duty gears, camshafts, highly stressed components | Medium-duty gears, shafts, moderate stress parts | Aerospace, high-performance components | Hot and cold work tools, dies | General engineering, non-nitrided applications |
Quality Assurance and Testing
Every batch of FUSHUN METAL’s 41CrAlMo7-10 Steel undergoes rigorous testing to ensure it meets our exacting quality standards:
- Chemical Composition Analysis: Spectrographic testing to verify precise element content critical for performance, with special attention to aluminum, chromium, and carbon levels.
- Mechanical Property Testing: Tensile testing, hardness testing, and impact testing to verify strength and toughness properties.
- Microstructural Examination: Metallographic analysis to verify proper structure, grain size, and inclusions.
- Ultrasonic Testing: 100% ultrasonic inspection for critical applications to ensure internal soundness.
- Dimensional Inspection: Comprehensive dimensional verification to ensure tight tolerances.
- Hardenability Testing: Jominy end-quench testing to verify through-hardening capability.
- Nitriding Response Testing: Sample nitriding tests to verify surface hardness and case depth potential.
- Cleanliness Testing: Inclusion content analysis to ensure high steel quality.
- Surface Quality Inspection: Visual and magnetic particle inspection to detect surface defects.
- Heat Treatment Verification: Testing of heat-treated samples to verify response to thermal processing.
Certifications Provided
- Material Test Certificates according to EN 10204 3.1
- Chemical composition analysis
- Mechanical property test results
- Dimensional inspection report
- Heat treatment certification when applicable
- Special property verifications available upon request
- Certificate of conformity to ordered specifications
- Ultrasonic testing reports when specified
- Nitriding response test reports when specified
Why Choose FUSHUN METAL for 41CrAlMo7-10 Steel
When you select FUSHUN METAL as your supplier for 41CrAlMo7-10 Steel, you partner with a leading manufacturer committed to excellence:
- Comprehensive Product Range: Extensive range of product forms to meet diverse application requirements.
- Technical Expertise: In-depth knowledge of nitriding steels and their applications.
- Custom Solutions: Ability to provide custom shapes, sizes, and pre-processed components.
- Quality Assurance: Stringent quality control processes ensuring consistent properties.
- Metallurgical Support: Technical guidance for material selection, heat treatment, and application optimization.
- Global Supply Capability: Reliable worldwide shipping and logistics solutions.
- Cost-Effective Solutions: Competitive pricing combined with superior quality and service.
- Industry Experience: Extensive experience serving automotive, aerospace, and industrial machinery sectors.
- Innovation: Ongoing research and development to enhance product performance.
- Sustainability Focus: Commitment to environmentally responsible manufacturing practices.
- Rapid Delivery: Extensive inventory of standard sizes for quick delivery.
- Complete Documentation: Comprehensive certification and testing reports.
Request Information
Contact FUSHUN METAL today to discuss your 41CrAlMo7-10 Steel requirements. Our technical team is ready to assist you with:
- Detailed product specifications
- Technical consultations for your specific application
- Heat treatment recommendations for optimal properties
- Custom dimension and processing requirements
- Pricing inquiries and delivery schedules
- Sample requests for evaluation
FUSHUN METAL – Your trusted partner for premium nitriding steel solutions that deliver consistent quality, superior surface hardness, and excellent core strength for the most demanding industrial applications.
