Scientific background of a famous used train wheel, cast in the foundry of Abraham Ganz in 1867

What is it about?

Case hardened, double-walled train wheel, produced in the foundry of Abraham Ganz in 1867 and used for long time on the railroad tracks, was studied and evaluated by modern methods of materials sciences. The investigations indicated the presence of 0.059m% antimony (Sb), distributed uniformly in the material of the wheel. This quantity is several times higher than the average Sb amounts (<0.01m%) of the other components get into the castings. Sb was detected even in the several mm thick crust; except in the outermost surface layer with < 1 μm thickness. Based on the 20th century comprehensive studies, the antimony content, detected in the wheel, was found to be ideal. In grey iron it is a powerful pearlite stabilizer which has favourable effects on its mechanical properties and serviceability. The investigation of the surface structure proved that the excellent hardness (~600 HV) at the crust surface was due to the “nano-composite” structure formed from the pearlite as a consequence of severe plastic deformation during service. This was also promoted by the high amount (4.09m%) of carbon present in the casting. The microstructure refinement during operation most probably contributes to the long service lifetime of the wheels. The secret of the Abraham Ganz’s train wheels is inherently present – besides the novel construction and production technology (case hardening) – in the above mentioned composition and the structure of the material.

Featured Image

Why is it important?

In the time of Abraham Ganz, in the 19th century only practical observations and many experiments could merely result in technologies, bringing competitive products and economical success. The materials science background of the technology of casting rail wheels by 21th century methods reveals its secrets and its lessons for the present technologies as well as history of science.

Perspectives