W6Mo5Cr4V2 is a widely used tungsten-molybdenum (tungsten-molybdenum series high-speed steel) with excellent comprehensive performance. It is a key material in the field of metal cutting tools and precision wear-resistant components, favored for its balanced hardness, toughness, and heat resistance.
1. Chemical Composition
The chemical composition of W6Mo5Cr4V2 is precisely formulated to optimize its performance, with key elements and their content ranges as follows:
Carbon (C): 0.80~0.90% (Forms carbides to enhance hardness and wear resistance).
Silicon (Si): 0.20~0.45% (Aids in deoxidation during smelting and improves strength).
Manganese (Mn): 0.15~0.40% (Enhances hardenability and reduces brittleness).
Phosphorus (P): ≤0.030% (Strictly controlled to avoid material embrittlement).
Sulfur (S): ≤0.030% (Minimized to prevent toughness degradation).
Chromium (Cr): 3.80~4.40% (Improves corrosion resistance and forms wear-resistant carbides).
Vanadium (V): 1.75~2.20% (Forms hard vanadium carbides, significantly boosting wear resistance).
Tungsten (W): 5.50~6.75% (Enhances hot hardness and high-temperature strength).
Molybdenum (Mo): 4.50~5.50% (Synergizes with tungsten to improve heat resistance and toughness).
2. Core Performance Characteristics
W6Mo5Cr4V2 high-speed steel stands out in demanding industrial environments due to its balanced properties:
High Hardness: After proper heat treatment, its hardness can reach 63~65 HRC, ensuring excellent cutting ability and wear resistance during long-term use.
Good Hot Hardness: Maintains a hardness of over HRC 55 at 600℃, retaining cutting performance even under prolonged high-temperature conditions (e.g., continuous medium-load cutting).
Balanced Toughness: Compared to high-cobalt grades, it offers better impact toughness, reducing the risk of chipping or (fracture) in interrupted cutting or medium-load applications.
Excellent Wear Resistance: Uniformly distributed carbides (from tungsten, vanadium, and chromium) provide strong resistance to abrasive wear, extending tool lifespan.
Machinability: In the annealed state, it can be processed by grinding, milling, and turning, facilitating the manufacturing of complex-shaped tools.
3. Heat Treatment Process
Proper heat treatment is crucial to unlocking the optimal performance of W6Mo5Cr4V2. The standard process includes:
Annealing: Heat to 820~870℃, hold for 2~4 hours, then furnace-cool at a rate of 10~20℃/h to 500℃, followed by air cooling. After annealing, hardness is ≤255 HBW, ensuring machining convenience.
Preheating: Two-stage preheating is recommended: first to 600~650℃, then to 800~850℃, to reduce thermal stress and ensure uniform heating.
Quenching: Heat to 1210~1230℃, hold for 10~15 minutes (adjust based on workpiece size), then oil quench or air cool. This step forms a martensitic structure for high hardness.
Tempering: Temper at 540~560℃ for 2~3 hours, repeating 2~3 times to eliminate residual stress and stabilize the structure. The final hardness is adjusted to 63~65 HRC.
4. Typical Applications
W6Mo5Cr4V2 high-speed steel is widely used in manufacturing cutting tools and wear-resistant components across various industries:
Cutting Tools: Ideal for producing high-performance tools such as drills, end mills, taps, reamers, and gear hobs. It performs excellently in machining carbon steel, alloy steel, and cast iron.
Medium-Load Machining: Suitable for continuous or interrupted cutting operations, including medium-speed milling and turning of general engineering materials.
General-Purpose Tooling: Used in manufacturing dies, punches, and precision wear parts requiring a balance of hardness and toughness.
Automotive and Machinery Industries: Commonly applied in mass production lines for processing shafts, gears, and structural components.
5. Advantages and Limitations
Advantages: Offers a cost-effective balance between hardness, toughness, and wear resistance; widely available in the market; easy to process and heat treat.
Limitations: Hot hardness is lower than cobalt-containing grades (e.g., M35, M42), making it less suitable for continuous cutting of high-temperature alloys or ultra-high-speed machining scenarios.
With its reliable performance and versatility in medium-load applications, W6Mo5Cr4V2 remains a staple material in the global tooling industry, supporting efficient and precise metal processing across diverse sectors.