How did Robert Hadfield’s manganese steel improve wear resistance?

Robert Hadfield’s manganese steel—an austenitic alloy typically containing about 12 percent manganese and 1.2 percent carbon—improves wear resistance through its exceptional work-hardening capabilities.123

When the surface of this steel is subjected to pounding or deformation, it creates a high density of disturbances within the crystal lattices. These disturbances effectively block the flow of dislocations, causing the material to become stronger as it is subjected to more impact. Because manganese acts as a strong austenizer, it maintains the steel's austenitic structure at room temperature, allowing it to retain this unique capacity for hardening under stress. This durability makes the alloy particularly effective for high-impact applications such as rock-crushing machinery and railroad rails.234