1. Raw Material Selection & Pretreatment

High-performance materials like high-phosphorus cast iron, boron cast iron, or alloy cast iron are used (for premium models). Raw cast iron ingots undergo strict inspection (spectral analysis, hardness testing) to ensure element content meets standards. They are then blended with clean scrap and melted in an intermediate frequency furnace at 1400–1500°C, with composition adjusted via sampling

2. Casting: Forming the Blank

• Centrifugal casting is preferred (superior density due to centrifugal force pushing impurities inward). The process involves:

• Preparing a rotating metal mold (800–1200r/min) coated with release agent (e.g., graphite).

• Pouring molten iron (1300–1350°C) into the mold; it solidifies against the mold wall under centrifugal force.

• Demolding at 300–400°C (to avoid cracking) and cleaning (removing risers, burrs).

  
  

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3. Heat Treatment: Optimizing Properties

Annealing (800–850°C, 2–4h holding, slow cooling) eliminates internal stress, reduces hardness (HB180–220), and improves machinability. Special alloys may undergo aging or surface quenching.

4. Machining: Ensuring Precision

• Rough machining: Turning outer surfaces (removing scale, leaving finish allowance) and drilling holes (e.g., water jacket holes for wet liners).

• Semi-finishing: Boring inner holes (preliminary sizing) and precision turning outer surfaces (ensuring coaxiality ≤0.02mm).

• Finishing: Honing inner holes (key step) with diamond/CBN stones to create a uniform crosshatched surface (Ra0.4–0.8μm) for lubrication, achieving tight tolerances (±0.01mm for inner diameter, roundness/cylindricity ≤0.005mm).

  
  

5. Optional Surface Treatment

• Phosphating: Forms a 2–5μm anti-rust film.

• Chromium plating: Adds a 0.05–0.1mm hard chromium layer (HV800–1000) for high-wear scenarios.

• Molybdenum spraying: Enhances lubricity and heat resistance (common for diesel engines).

  To reduce errors, we use imported military-grade aeromodelling machines from Germany (the first in China).

  As shown below，

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6. Final Inspection & Delivery

• Full inspection: Dimensional checks (inner/outer diameter, length), mechanical property sampling (hardness, tensile strength), and non-destructive testing (ultrasonic flaw detection).

• Test fitting: Random samples are assembled with standard cylinder blocks/pistons to verify clearance.

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If you need any form of cylinder liner customization, please feel free to contact us at any time and share your requirements with us. We will provide you with the best cylinder liners! And Welcome to visiting if you like!