An overview of the iron pad
The iron pad under the rail between the rail and the sleeper is one of the important components in the track structure, and plays an important role in damping vibration in the wheel-rail power system. With the development of heavy-duty railway transportation, the axle load is increasing day by day. While the rails are gradually becoming heavier, higher requirements are placed on the performance of the backing plate. It is required that the backing plate has good vibration damping performance, impact resistance and long service life.
2. The technical evolution of iron backing plate
As the speed of the train increases, the requirements for the stability of the track line are gradually increased, and the railway track pad has also undergone four improvements. The use of steel plate group welding backing plate, due to the existence of welds in the group welding backing plate, the integrity is not high, and the existence of the welding seam weakens the mechanical properties of the backing plate. The profiled steel backing plate replaces the group welding backing plate due to its good integrity and high mechanical properties. However, due to the long backing plate, the deformation of the profiled steel backing plate is large and the corrosion is serious, and the profiled steel part also has the disadvantage that the production cannot meet the current structural form of the rail backing plate. People gradually turn to malleable cast iron pads with small deformability and low cost. Since the production of malleable cast iron is obtained by forge annealing of white cast iron, compared with the production process of directly obtaining castings in the as-cast state, this production method prolongs the production cycle and increases the production cost. Since its inception, ductile iron has attracted much attention because of its excellent mechanical properties and good casting properties, and the iron ductile iron backing plate that can be used in the as-cast state is the choice to replace the malleable iron backing plate. Due to its strong anti-vibration and impact resistance, ferritic ductile iron is used in the manufacture of track accessories, such as iron pads for subway line accessories, fast track pads, embedded iron seats, rail pads for passenger dedicated lines, etc. .
3. Quality assurance of iron backing plate production
1. For the inspection and testing of raw materials, we require suppliers to provide inspection indicators such as production batch number, chemical composition, and mechanical properties.
2. Our quality control inspectors take sample sampling and batch testing and provide raw material material certificates for control during the testing process.
3. According to the different requirements of the products, we make corresponding physical and chemical tests and inspections. If the result does not meet our requirements, we will refuse to accept it and only the material will be accepted if it meets our standards.
4. For the semi-finished products and their outsourced manufacturers, we often organize quality control coordination meetings, and provide technical support and guidance. Guaranteed delivery of qualified products to our customers prior to shipment.