Tungsten steel spool sleeve for valve

I. Material Characteristics & Physical Properties

Tungsten steel (also known as cemented carbide) is manufactured via powder metallurgy process with tungsten carbide (WC) as the matrix and cobalt (Co) as the binder phase.
• Hardness: HRA 89.5–93 (equivalent to HRC 74+), significantly exceeding tool steels (HRC 60–65);
• Density: 13.96–14.95 g/cm³, high densification reduces medium permeation risks;
• Transverse rupture strength: 3200–4500 MPa, >10× higher than conventional steels;
• Temperature resistance: Long-term stability at 750°C, instantaneous tolerance to 1000°C;
• Grain size: 0.4–2.0 μm, fine-grained structure enhances material homogeneity and crack resistance.

II. Core Performance Advantages

1. Extreme Wear Resistance
   o Withstands high-velocity erosion by abrasive media (e.g., sand, silicon powder @62HRC); extends service life 3–5× in sand-laden/oil-heavy well drilling.
   o Mirror polishing (Ra 0.2 finish) reduces friction coefficient, minimizing adhesive wear against the spool.

2. High-Pressure Endurance & Deformation Resistance
   o Transverse rupture strength ≥4000 MPa enables sustained operation under 25 MPa working pressure; ideal for high-pressure components (e.g., hydraulic pump seal sleeves, thrust rings).
   o Young's modulus 570–620 GPa ensures stable mating clearance (coaxiality ≤0.012mm), preventing internal leakage.

3. Corrosion Resistance & Thermal Stability
   o Stable against hydrochloric/sulfuric acid and aqua regia; suitable for sulfur-containing media (coal chemical) and acidic oil-gas environments.
   o Low thermal expansion coefficient (4.5–5.5×10⁻⁶/K) minimizes deformation at high temperatures, maintaining sealing pair conformity.

4. Precision Machining Compatibility
   o Geometric tolerance control to ±0.002 mm (e.g., cylindricity 0.005mm), meeting dynamic sliding-fit requirements for spool-sleeve assemblies.
   o Capable of machining complex structures (e.g., φ1.588mm micro-holes, tapered sealing pairs), adaptable to high-precision systems (dispensing valves, proportional valves).

III. Typical Applications

1. Energy Extraction: Oil drilling valves (e.g., bypass valves, pump valve sleeves) resisting sand erosion & H₂S corrosion;

2. High-Temperature Fluid Control: Coal chemical valves (handling coal-water slurry, silicon powder) enduring 750°C thermal shock;

3. Precision Fluid Systems: Dispensing valve sleeves, hydraulic servo valves enabling microliter-level flow control via high-precision fits;

4. Military & Heavy Industry: Naval hydraulic systems, armor-piercing projectile valves requiring high-pressure deformation resistance and instant impact tolerance.

IV. Summary

The tungsten steel spool sleeve resolves critical reliability/lifetime bottlenecks in specialty valves under extreme conditions through its triad of characteristics:
Ultra-Hard Wear Resistance + Corrosion/Pressure Resistance + Precision Stability.
Compared to traditional materials, it reduces replacement frequency by >60% and significantly lowers maintenance costs.