High-strength Titanium Alloy Forged Ball Valves

Product Process: The Precision Manufacturing of Titanium Alloy Forging

(1) Forging Process: The Transformation from Titanium Ingot to Valve Body

• Vacuum Melting: Uses a vacuum consumable arc furnace (VAR) to melt titanium alloy ingots, with impurity content controlled at C≤0.10%, N≤0.03%, H≤0.015% to ensure material purity.
• Isothermal Forging: Isothermal die forging at 900-950°C with a deformation rate ≤0.1mm/s, allowing metal flow lines to distribute along the valve body contour, enhancing mechanical properties by over 20% and avoiding coarse grain issues in traditional forging.
• Stress Relief Annealing: After forging, annealing at 650°C for 2 hours to eliminate internal stress, with a grain size reaching ASTM Grade 7 to ensure long-term service stability.

(2) Precision Machining and Surface Treatment

• 5-Axis Machining: Utilizes DMG MORI 5-axis machine tools, with valve seat sealing surface machining accuracy reaching IT6 grade and surface roughness Ra≤0.4μm, achieving 0.002mm-level error control with laser interferometers.
• Sealing System:
  • Soft Seal: PTFE or PEEK valve seats with a leakage rate ≤0.5cc/min (API 598 standard);
  • Metal Hard Seal: Titanium alloy surfacing with tungsten carbide (hardness HRC65+), suitable for particle-containing media, achieving zero leakage (API 6D VI grade).
• Surface Strengthening: Optional ion nitriding (TiN coating) increases surface hardness to HV1200, extending wear life by 3 times, suitable for high-frequency switching scenarios.

(3) Full-Process Quality Control

• Material Traceability: Each titanium ingot has a unique heat number, fully traceable from melting to finished product, supporting third-party testing (e.g., SGS).
• Pressure Testing: 100% shell pressure testing (medium: water or kerosene) with no leakage under pressure for 30 minutes; helium leak detection for sealing testing with a leakage rate ≤1×10⁻⁹Pa·m³/s (suitable for high-purity media scenarios).