Special grinding wheels for railway turnout rails
Railway turnouts, crucial for directing trains across tracks, are widely used in stations, marshalling yards, and track junctions. By adjusting the switch rails and frog, they ensure efficient and safe train operations.
Fashan manufactures dedicated grinding wheels for railway turnouts.
Solution for grinding turnout switch rails
Measure the profile with a profiler and inspect issues like basic rail flaking, switch rail flaking, metal loss, rail corrugations, and poor rail head contact. Analyze the data to determine a grinding program.
Grinding the non - working edge of switch rails
Non-working side grinding of switch rails aims to eliminate excessive flange on the gauge side. The procedure includes positioning the switch rail to the open configuration, selecting a switch grinding machine, adjusting the grinding wheel height to exceed the milled platform level on the non-working side, aligning the grinding wheel angle parallel to the planed surface of the switch rail, and performing incremental grinding passes until the flange on the non-working surface is fully removed.
Eliminate the flashing on the cutting face of the basic rail
Grind the working edge of the basic rail with a turnout grinder to eliminate the edge flash
Grinding the top surfaces of switch rails and basic rails
Switch/stock rail top grinding is a targeted process for eliminating surface defects including fish-scale cracks, spalled fragments, and irregular contact patterns on rail heads.
Grinding the frog corrugations before treatment
After frog corrugation grinding
Frog section grinding solutions
The frog, a core component of railway switches, guides wheelsets to transition smoothly between tracks and consists of a point rail, wing rails, and guard rails. High-frequency wheel-rail impacts induce stress concentration, leading to fatigue cracks. Contact fatigue causes metal layer fragmentation and spalling, resulting in rail surface deterioration. Wear in the frog throat area disrupts wheel-rail contact relationships, causing geometric deformation. Grinding repairs damage by eliminating surface cracks and spalled fragments while restoring rail surface flatness. Optimizing contact geometry through profile correction reduces wheel-rail impact forces, ultimately extending service life (20%-40% lifespan increase) with reduced replacement frequency and maintenance costs.
Core Design Objectives
Match the contour profiles of frog components (point rail, wing rails, guard rail), particularly the curved section of the point rail and throat area.
Efficiently remove defects: Precision material removal targeting fatigue cracks, spalled fragments, and other characteristic damage modes.
Zone-Specific Grinding Wheel Customization
Point Rail Grinding: Repair arc-surface cracks while maintaining curvature continuity.
Narrow-profile curved wheels(20-30mm width) with ±15° axial adjustment to adapt to varying switch radii.
Wing/Guard Rail Grinding Eliminate planar spalling and correct lateral deviations. Multi-disc segment grinding wheels ensure rail surface parallelism error ≤0.1mm.
Zirconia-Alumina (ZA) Abrasive Implementation
Zirconia-alumina (ZA), a composite abrasive of aluminum oxide (Al₂O₃, 75-80%) and zirconium oxide (ZrO₂, 20-25%), forms a dense microcrystalline structure via hot-pressing. This combines high hardness with fracture toughness.
Performance Enhancements:
Wear Resistance↑: Hot-pressing reduces internal porosity, achieving 22-24 GPa hardness (10-15% improvement over conventional fused ZA).
- Impact Resistance↑: ZrO₂ phase transformation toughening (tetragonal → monoclinic) inhibits crack propagation.
- Cutting Efficiency↑: Sharp microcrystalline structure reduces grinding heat and improves chip evacuation.