Nippon Steel and Sumitomo Metal developed a highly durable railroad wheel for railroad vehicles in the U.S. that transport heavy cargoes. It does not abrade away easily, and it is two times more durable than the existing railroad wheel. The company shipped 1,000 sheets to railroad companies in the U.S. for the substantiative experiment. The company increased the carbon content in the steel for higher intensity. Steel becomes liable to display cracks should the intensity increase, but the company improved the manufacturing process to increase intensity and durability simultaneously.
In the U.S., the double stack train that carries one container on top of another is widespread. Accordingly, wheel and rail need to bear a large amount of burden. The new railroad wheel from Nippon Steel and Sumitomo Metal conforms to the specifications set by the railroad industry association of the U.S., and only three companies – Nippon Steel and Sumitomo Metal, its subsidiary in the U.S., and an American company – are allowed to manufacture this new product. Annual demand for railroad wheels is 1,200,000 sheets in the U.S., and Nippon Steel and Sumitomo Metal estimates that the new product will account for 70% in the market in the future. The new product will be promising for railroad wheels also in Australia and Brazil where railroad cars transport heavy natural resources.
A double stack train near Tucson in Arizona