Fishplate Wear Mechanism and Wear-Resistant Measures
- What are the main types of wear of fishplates?
The main types of wear of fishplates include adhesive wear, when there is high pressure on the contact surface between the fishplate and the rail, micro-convex points on the metal surface adhere, and the adhesion points are torn during relative movement, resulting in wear; abrasive wear, hard particles such as sand and rust in the track enter the contact surface, causing cutting or scratching on the fishplate surface during relative movement; fatigue wear, under alternating contact stress, fatigue cracks occur on the fishplate surface, and crack propagation leads to material spalling and wear; and corrosive wear, in humid environments, surface rust and wear together accelerate material loss.
- What are the factors affecting the wear rate of fishplates?
Load size is an important factor, the greater the load, the higher the contact surface pressure, and the faster the wear rate; train running speed affects the relative movement speed, the higher the speed, the more severe the wear; the material matching between the fishplate and the rail, if the hardness difference between the two is too large, it is easy to accelerate the wear of one of them; surface roughness, excessive roughness will increase the initial wear rate; environmental factors such as humidity and dust content will also affect the wear rate, and humid and dusty environments will accelerate wear.
- How to improve the wear resistance of fishplates through material improvement?
Use low-alloy high-strength steel such as Q345B, and improve the hardness and toughness of the steel by adding alloy elements such as chromium and molybdenum to enhance wear resistance; quench the surface of the fishplate to make the surface hardness reach HRC40-45, and keep the core with certain toughness, forming a "hard shell and soft core" structure, which is both wear-resistant and impact-resistant; use surfacing technology to surfacing wear-resistant alloys, such as tungsten carbide alloy, on the contact surface between the fishplate and the rail, significantly improving surface wear resistance.
- What is the impact of fishplate surface treatment on wear resistance?
Surface quenching can improve the surface hardness of the fishplate, reduce adhesive wear and abrasive wear, and increase wear resistance by more than 30%; carburizing treatment can increase the carbon content of the surface layer, and the hardness is improved after quenching and tempering, and wear resistance is enhanced, but too thick a carburized layer may increase surface brittleness; shot peening improves surface residual compressive stress through surface strengthening, reducing fatigue wear; coating wear-resistant coatings such as ceramic coatings can effectively isolate the contact surface and reduce the wear rate, but the coating must be firmly bonded to the substrate.
- What are the maintenance measures to reduce fishplate wear during use?
Regularly clean sand and debris in the track to reduce abrasive wear; keep the fishplate and rail tightly connected to avoid relative sliding caused by loosening and reduce adhesive wear; regularly check the surface wear of the fishplate, and replace it in time when the wear amount exceeds 3mm; in areas with severe wear such as curve sections, use fishplates with better wear resistance and shorten the inspection cycle; regularly lubricate the fishplate, apply grease on the contact surface to reduce the friction coefficient and reduce wear.