Carpenter,Micro-Melt® M-42 Alloy (AISI M42)

Carpenter Micro-Melt® M-42 Alloy (AISI M42) Product Information -:- For detailed product information, please contact sales. -: Carpenter Micro-Melt® M-42 Alloy (AISI M42) Synonyms -:- For detailed product information, please contact sales. -:

Carpenter Micro-Melt® M-42 Alloy (AISI M42) Product Information -:- For detailed product information, please contact sales. -: ## **Carpenter Micro-Melt® M-42 Alloy (AISI M42)** ### **Premium Cobalt High-Speed Steel for Maximum Hardness and Cutting Performance** --- ### **Product Overview** Carpenter Micro-Melt® M-42 is an advanced molybdenum-cobalt high-speed steel (HSS) produced through proprietary powder metallurgy (PM) technology. As the premium PM version of conventional AISI M42, this alloy delivers **exceptional hardness capability (67-70 HRC)**, superior **hot hardness**, and outstanding **wear resistance** for the most demanding cutting applications. The Micro-Melt process creates an ultra-fine, homogeneous microstructure that overcomes the carbide segregation limitations of conventional M42, providing significantly improved grindability, toughness consistency, and predictable performance in extreme service conditions. --- ### **Key Advantages** - **Maximum Hardness Potential**: Achieves 67-70 HRC – among the highest of all commercial high-speed steels - **Superior Hot Hardness**: Excellent red hardness retention up to 600°C (1112°F) due to 8% cobalt content - **Enhanced Grindability**: PM structure reduces grinding time and improves surface finish compared to conventional M42 - **Improved Toughness**: Better transverse rupture strength and impact resistance than conventionally produced M42 - **Isotropic Properties**: Uniform performance in all material directions - **Consistent Heat Treatment**: Minimal distortion and predictable dimensional stability - **Excellent Wear Resistance**: High vanadium content combined with fine carbides provides outstanding abrasion resistance --- ### **Chemical Composition (%)** | Element | Carbon (C) | Molybdenum (Mo) | Cobalt (Co) | Tungsten (W) | Chromium (Cr) | Vanadium (V) | |---------|------------|-----------------|-------------|--------------|---------------|--------------| | **Content** | 1.05-1.15 | 9.00-10.00 | 7.75-8.75 | 1.15-1.85 | 3.50-4.25 | 0.95-1.35 | | Element | Silicon (Si) | Manganese (Mn) | Sulfur (S) | Phosphorus (P) | |---------|--------------|----------------|------------|----------------| | **Content** | 0.15-0.40 | 0.15-0.40 | ≤0.030 | ≤0.030 | *Primary Features: High cobalt (8%) for hot hardness, balanced Mo-W for secondary hardening, moderate vanadium for wear resistance* --- ### **Physical & Mechanical Properties** #### **Physical Properties** - **Density**: 8.00 g/cm³ (0.289 lb/in³) - **Melting Point**: 1260-1315°C (2300-2400°F) - **Thermal Conductivity**: 25.0 W/m·K at 20°C - **Coefficient of Thermal Expansion**: 10.5 × 10⁻⁶/°C (20-300°C) - **Modulus of Elasticity**: 215 GPa (31.2 × 10⁶ psi) - **Magnetic Properties**: Slightly magnetic in annealed condition #### **Mechanical Properties (Hardened & Tempered)** - **Typical Hardness Range**: **66-70 HRC** (67-68 HRC optimal for most applications) - **Red Hardness**: Maintains 60 HRC at approximately **600°C (1112°F)** - **Hot Hardness at 600°C**: 850-900 HV - **Compressive Strength**: 3,800-4,200 MPa (551-609 ksi) at 68 HRC - **Transverse Rupture Strength**: 3,400-3,800 MPa (493-551 ksi) - **Abrasion Resistance**: Excellent – superior to M2 and comparable to M4 #### **Heat Treatment Parameters** 1. **Annealing**: - Temperature: 840-870°C (1545-1600°F) - Slow cool to 540°C (1000°F) at 10°C (20°F)/hour - Air cool to room temperature - *Annealed Hardness*: 240-280 HB 2. **Stress Relieving**: 600-650°C (1112-1200°F) for 2 hours 3. **Preheating**: Critical two-stage process: - Stage 1: 550-650°C (1022-1200°F) - Stage 2: 800-850°C (1472-1562°F) 4. **Austenitizing**: **1170-1200°C (2140-2190°F)** - Temperature control critical (±5°C recommended) - Soaking time: 2-5 minutes per 25mm (1 inch) of thickness 5. **Quenching Options**: - Oil quenching: For maximum hardness - Salt bath: For complex shapes - Vacuum/pressurized gas: Best for dimensional control 6. **Tempering**: - **Triple temper mandatory** for maximum properties - Temperature: 540-570°C (1000-1060°F) - Duration: 2 hours minimum per cycle - Cool to room temperature between tempers - *Typical hardness after tempering*: 67-69 HRC --- ### **International Standards & Cross-References** | Standard System | Designation | Notes | |----------------|-------------|-------| | **Carpenter** | Micro-Melt M-42, CPM M42 | Primary designation | | **AISI** | M42 | Direct equivalent (PM premium version) | | **UNS** | T11342 | Unified numbering system | | **ISO** | HS2-9-1-8 | ISO 4957 designation | | **European (EN)** | 1.3247 | Similar cobalt HSS grade | | **DIN** | S2-10-1-8 | German standard designation | | **Japanese (JIS)** | SKH59 | Equivalent cobalt HSS | | **Chinese (GB)** | W2Mo9Cr4VC08 | National standard | | **Common Equivalents** | ASP 2060 (Erasteel), HAP 72 (Hitachi) | Similar PM cobalt HSS grades | --- ### **Typical Applications** #### **1. High-Performance Cutting Tools** - **End Mills**: For hardened steels, titanium, and high-temperature alloys - **Drills**: High-penetration drills for difficult materials - **Reamers**: Precision hole finishing in hard materials - **Gear Cutters**: Hobs and shapers for automotive and aerospace components - **Broaches**: For internal splines and keyways in tough materials - **Thread Mills**: For hard materials and exotic alloys - **Turning Tools**: Single-point tools for precision machining #### **2. Specialized Industrial Tools** - **Cold Work Applications**: Punches and dies requiring extreme hardness - **Shear Blades**: For cutting high-strength materials - **Slitter Knives**: In metal processing lines - **Woodworking Tools**: For abrasive composite materials #### **3. Precision Components** - **Injection Mold Components**: Cores, cavities, and inserts for abrasive plastics - **Die Casting**: Cores and pins for aluminum and zinc casting - **Wear Parts**: In severe service environments requiring maximum hardness - **Machine Components**: Guide pins, bushings, and wear plates #### **4. Aerospace & Defense Applications** - **Aircraft Component Machining**: Landing gear, engine components - **Missile System Components**: Precision parts requiring wear resistance - **Satellite Components**: High-reliability mechanisms --- ### **Performance Characteristics** #### **Cutting Performance Comparison** | Material Being Cut | Speed vs. M2 | Feed Rate | Tool Life Improvement | |--------------------|--------------|-----------|----------------------| | **Stainless Steel** | 140-160% | 120-130% | 250-400% | | **Titanium Alloys** | 150-180% | 130-140% | 300-500% | | **High-Temp Alloys** | 160-200% | 140-150% | 400-700% | | **Hardened Steels (45-55 HRC)** | 120-140% | 110-120% | 200-350% | | **Aluminum Alloys** | 100-110% | 100-105% | 100-150% | #### **Compared to Conventional M42** | Property | Micro-Melt M-42 | Conventional M42 | Improvement | |----------|-----------------|------------------|-------------| | **Toughness** | Very Good | Good | +30-40% | | **Grindability** | Good | Fair | +50-60% | | **Wear Resistance** | Excellent | Very Good | +15-20% | | **Hardness Consistency** | Excellent | Good | Dramatically improved | | **Distortion Control** | Excellent | Fair | +80-100% | --- ### **Machining & Fabrication Guidelines** #### **In Annealed Condition** - **Machinability Rating**: Fair (40-45% of 1% carbon steel) - **Recommended Tools**: Carbide tools preferred for best results - **Cutting Speeds**: 20-30 SFM for turning operations - **Feed Rates**: Light to moderate - **Coolant**: Essential – use water-soluble or straight oils #### **In Hardened Condition** - **Grinding Requirements**: - Use CBN or aluminum oxide wheels (soft grade) - Light passes: ≤0.015mm (0.0006") per pass - Frequent wheel dressing essential - Ample coolant flow required - Avoid grinding burns – watch for discoloration - **EDM Machining**: - Possible with proper parameters - Post-EDM tempering at 150-200°C (300-400°F) recommended - Remove recast layer for critical applications - **Polishing**: Achieves excellent mirror finishes with diamond compounds --- ### **Technical Specifications** #### **Quality Standards** - **Micro-Cleanliness**: Exceeds ASTM E45 requirements - **Carbide Size**: 2-4 microns maximum - **Carbide Distribution**: Uniform, non-directional - **Decarburization**: Controlled to ≤0.10mm (0.004") - **Surface Quality**: Various finishes available (ground, polished, peeled) #### **Available Forms** - **Round Bars**: 3mm to 300mm diameter - **Flat Bars**: Various thicknesses and widths - **Sheets & Plates**: Up to 100mm thickness - **Forgings**: Custom shapes and sizes - **Pre-finished Blanks**: Ground and polished to customer specifications - **Wire**: For specialized applications --- ### **Heat Treatment Special Considerations** #### **Critical Success Factors** 1. **Atmosphere Control**: Essential to prevent decarburization and oxidation 2. **Temperature Uniformity**: ±5°C (±10°F) tolerance throughout furnace 3. **Quenching Rate Control**: Critical for complex shapes 4. **Tempering Completeness**: Must complete all tempering cycles #### **Recommended Equipment** - Vacuum furnaces with high-pressure gas quenching - Salt baths with proper neutralization - Controlled atmosphere mesh belt furnaces - Precision tempering furnaces with air circulation #### **Common Pitfalls to Avoid** - Inadequate preheating leading to thermal shock - Excessive austenitizing temperature causing grain growth - Insufficient tempering resulting in retained austenite - Improper cooling between tempers --- ### **Application-Specific Recommendations** #### **Optimal For** - Materials with hardness > 40 HRC - High-temperature alloys (Inconel, Hastelloy, Waspaloy) - Abrasive composite materials - High-speed machining operations - Dry or minimal lubrication cutting - Applications requiring maximum hardness #### **Economic Justification** - **Tool Life**: 3-7× conventional HSS tools - **Productivity**: 30-60% higher cutting speeds possible - **Quality**: Superior surface finishes and tighter tolerances - **Downtime**: Reduced tool change frequency - **Total Cost**: Lower cost-per-part in demanding applications **Typical ROI**: 3-8 months in aerospace, medical, and die/mold applications --- ### **Limitations & Considerations** #### **Technical Challenges** - **High Cost**: Premium pricing compared to standard HSS grades - **Grinding Requirements**: Still requires careful grinding practices - **Heat Treatment Complexity**: Demands precise control - **Brittleness Concerns**: Lower impact resistance than tough grades - **Availability**: May require longer lead times for special sizes #### **Not Recommended For** - High-impact applications with shock loading - Tools with extremely thin sections (<1mm) - Applications requiring frequent heavy regrinding - Highly corrosive environments without protection - Cost-sensitive applications where performance premium isn't justified --- ### **Coating Compatibility** Micro-Melt M-42 provides an excellent substrate for advanced PVD and CVD coatings: #### **Recommended Coatings** - **PVD Coatings**: TiAlN, AlCrN, TiSiN, DLC - **CVD Coatings**: TiCN, Al₂O₃, diamond-like carbon - **Hybrid Coatings**: Multi-layer combinations #### **Coating Benefits** - **Tool Life Improvement**: Additional 100-400% increase - **Cutting Speed Increase**: 20-40% higher speeds possible - **Friction Reduction**: Improved chip flow and surface finish - **Thermal Barrier**: Protection against heat penetration #### **Coating Process Notes** - Apply after final heat treatment and grinding - Typical coating thickness: 2-5 microns - Can be reapplied after tool regrinding - Compatible with most commercial coating systems --- ### **Industry-Specific Applications** #### **Aerospace Industry** - Machining turbine blades and disks - Drilling and milling titanium structures - Manufacturing landing gear components - Engine part production and repair #### **Medical Device Manufacturing** - Machining surgical implants (titanium, cobalt-chrome) - Manufacturing orthopedic instruments - Producing dental tools and equipment - Machining biocompatible materials #### **Die & Mold Industry** - Hard milling of tool steels (up to 62 HRC) - Manufacturing precision injection molds - Creating EDM electrodes - Machining die casting dies #### **Automotive Industry** - Machining transmission components - Manufacturing engine parts - Producing suspension components - Cutting gear and spline forms --- ### **Maintenance & Regrinding Best Practices** 1. **Regular Inspection**: - Monitor flank wear and edge condition - Check for micro-chipping and cracks - Measure dimensional accuracy regularly 2. **Optimal Regrinding Intervals**: - Don't exceed 0.2mm (0.008") flank wear - Regrind before catastrophic failure occurs - Maintain original tool geometry 3. **Grinding Parameters**: - Wheel speed: 25-35 m/s (5000-7000 SFPM) - Downfeed: 0.005-0.015mm (0.0002-0.0006") per pass - Crossfeed: 0.5-2.0mm (0.020-0.080") per pass - Use ample coolant flow 4. **Post-Grinding Treatment**: - Stress relief temper at 150-200°C (300-400°F) - Clean thoroughly before recoating - Inspect for grinding burns --- ### **Storage & Handling** #### **Recommended Practices** - Store in dry, temperature-controlled environment - Protect from corrosion with appropriate coatings or papers - Handle with care to prevent edge damage - Use proper lifting equipment for heavy sections - Keep identification markings clear and legible #### **Shelf Life** - Annealed condition: Unlimited with proper storage - Hardened condition: No degradation with proper handling - Maintain inventory rotation (FIFO system) --- ### **Technical Support & Services** Carpenter Technology provides comprehensive support for Micro-Melt M-42: - **Application Engineering**: Customized tool design and material selection - **Heat Treatment Guidance**: Specific recommendations for customer applications - **Failure Analysis**: Root cause determination and corrective actions - **Training Programs**: Technical seminars and workshops - **Testing Services**: Material analysis and performance testing --- ### **Environmental & Safety Considerations** #### **Material Safety** - Contains cobalt – follow appropriate handling procedures - Grinding dust requires proper ventilation and collection - Recycling programs available for scrap material #### **Regulatory Compliance** - RoHS compliant - REACH registered - Meets international environmental standards --- ### **Conclusion** Carpenter Micro-Melt® M-42 Alloy represents the pinnacle of high-speed steel technology for applications demanding maximum hardness and cutting performance. By combining the inherent advantages of conventional M42 chemistry with the superior microstructure of powder metallurgy manufacturing, this material delivers: 1. **Unmatched Hardness**: 67-70 HRC capability for extreme wear resistance 2. **Superior Hot Hardness**: Excellent performance at elevated temperatures 3. **Enhanced Manufacturing**: Improved grindability and heat treatment response 4. **Consistent Performance**: Predictable results from PM manufacturing 5. **Versatile Applications**: Suitable for the most demanding cutting operations **Economic Benefits Summary:** - Extended tool life and reduced changeover frequency - Higher productivity through increased cutting parameters - Improved part quality and dimensional accuracy - Lower total machining costs in appropriate applications - Reduced scrap and rework rates For aerospace, medical, die/mold, and other high-performance manufacturing applications, Micro-Melt M-42 provides the technological edge needed to machine today's most challenging materials efficiently and reliably. While demanding careful application and proper heat treatment, its performance advantages consistently justify its premium positioning in the tool steel marketplace. When conventional high-speed steels reach their performance limits and carbide tools aren't economically viable, Micro-Melt M-42 offers the optimal solution – combining HSS toughness with near-carbide performance levels. --- *For specific application recommendations, heat treatment guidelines, or technical assistance, consult with Carpenter Technology's technical services team. Always refer to the latest technical data sheets for current specifications and handling instructions.* -:- For detailed product information, please contact sales. -: Carpenter Micro-Melt® M-42 Alloy (AISI M42) Specification Dimensions Size： Diameter 20-1000 mm Length <6930 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. -: Carpenter Micro-Melt® M-42 Alloy (AISI M42) Properties -:- For detailed product information, please contact sales. -:

Applications of Carpenter Micro-Melt® M-42 Alloy (AISI M42) -:- For detailed product information, please contact sales. -: Chemical Identifiers Carpenter Micro-Melt® M-42 Alloy (AISI M42) -:- For detailed product information, please contact sales. -:

Packing of Carpenter Micro-Melt® M-42 Alloy (AISI M42) -:- 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 Sheet/Plate 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 3401 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