The frog (or crossing) of a turnout is a very important component that is installed at the end of the turnout. This part plays a critical role in guiding rail vehicles through the diverging track; hence it is referred to as the “heart” of the turnout.
Frogs must be produced from Hadfield austenitic manganese steel in accordance with the UIC 866-O or EN 15689 standards.
Hadfield steels contain alloying elements, primarily manganese (around twelve percent by weight) and carbon (around one percent by weight), along with small amounts of other elements such as molybdenum, nickel, silicon, etc. These steels exhibit an austenitic structure in casting conditions (a type of crystalline structure of iron that is generally stable at high temperatures) and transform into martensite (a crystalline structure common in quenched steels that has very high hardness and strength) when subjected to deformation. Hadfield steels have medium strength and good ductility, and they are used in various industries, including rail, heavy construction machinery, cement, and more.
The weight of this component is approximately 0.3 tons, and it is produced through casting.
Production Steps for the Frog
- Design
- Casting and Heat Treatment
- Machining
- Welding the Rails to the Cast Frog