The application of quenching technology in rail manufacturing is a key process, mainly used to improve the hardness, wear resistance and fatigue resistance of rails.
Basic principles of quenching Quenching refers to a heat treatment method in which steel is heated above the critical temperature to make it completely austenitized, and then rapidly cooled (usually water or oil cooling) to obtain a martensitic structure. For rails, quenching can significantly enhance its surface hardness and wear resistance while maintaining the toughness of the core.
Main steps:
- Preheating: To prevent the rails from cracking due to sudden temperature changes, they are usually preheated first.
- Heating: Heat the rails to between 850°C and 950°C to ensure that the entire cross section is fully austenitized.
- Cooling: Use an appropriate medium (such as water or polymer solution) for rapid cooling to form a martensitic structure.
- Tempering: In order to reduce internal stress and adjust hardness, the quenched rails need to be tempered at low temperature.