Fishplate Wear Patterns and Repair Methods
- What are the common wear forms of fishplates?
Abrasion on the contact surface between the fishplate and the rail is a common form. Due to long - term friction between the two during train operation, the contact surface becomes uneven. Wear around the bolt holes is also common. Repeated extrusion and friction between the bolt and the hole wall make the hole diameter larger or the hole wall deformed. In addition, the edge of the fishplate may have chipping wear due to collision or stress concentration, and in heavy - haul lines, crack wear due to fatigue may also occur. These wears will affect the connection performance of the fishplate.
- What impact do different wear forms have on the performance of fishplates?
Abrasion on the contact surface will cause the fishplate and the rail to fit loosely, resulting in gaps, which will cause impact and vibration when the train passes, and aggravate the wear of other components. Wear of bolt holes will loosen the fit between bolts and holes, reduce the connection strength, and may cause rail displacement. Edge chipping wear will weaken the overall strength of the fishplate. If crack wear is not handled in time, it may expand and cause the fishplate to break, endangering driving safety.
- What is the judgment standard for the wear degree of fishplates?
When the abrasion depth of the contact surface exceeds 3mm, it is regarded as severe wear and needs to be handled. When the diameter of the bolt hole expands by more than 1mm, or the hole wall is obviously deformed, affecting the bolt fastening, it needs to be repaired or replaced. When the edge chipping length exceeds 50mm, or the crack depth exceeds 1/3 of the fishplate thickness, it is judged as unusable. For fatigue cracks, as long as cracks are found, regardless of size, it is necessary to evaluate whether to repair or replace.
- What are the repair methods for fishplates?
For slight abrasion on the contact surface, grinding can be used to smooth the contact surface and restore its fit with the rail. For slight wear of bolt holes, the method of reaming and then replacing with large - diameter bolts can be used for repair, but the reaming amount cannot exceed 10% of the original hole diameter. Small - scale edge chipping can be repaired by welding. After welding, grinding is required to ensure the shape is flat. Severely worn or cracked fishplates need to be replaced directly.
- How to prevent excessive wear of fishplates?
Regularly lubricate the fishplate, apply wear - resistant lubricant on the contact surface to reduce the friction coefficient. Reasonably control the train running speed and load to avoid overload operation aggravating wear. Strengthen the inspection of fishplates, and timely find and handle early wear. Select fishplates made of more wear - resistant materials, such as high - strength alloy steel, which can improve their wear resistance and extend the wear cycle.