Sheffield University scientists have ushered in a steel manufacturing breakthrough that they say could help lower the car industry’s CO2 emissions.
The Sheffield method uses copper which has so far been cast aside by the steel industry because of the detrimental effects it can have on certain types of steel.
Led by professors Mark Rainforth and Dr Junheng Gao, the team’s study has has shown how ultra-fine grained steel can be made to deliver world leading mechanical properties.
Thanks to the inclusion of copper, this technique can produce steel with a strength of nearly 2 GPa – for example a 1 cm diameter wire capable of holding a weight of 15 tonnes.
It can also produce steel with an elongation of 45%. This implies the steel would be ductile enough to form complex shapes.
Advanced imaging from NIST showed that when the steel is heat-treated during processing, the copper precipitates rapidly within the crystal grains of steel, rather than at the grain boundaries.
This restricts the growth of grains in the material’s microstructure, leaving an ultrafine-grained microstructure which imparts the high strength and superior ductility, but also enhances its thermal stability.
According to the scientists, the combination of these properties makes this steel particularly appealing to automotive manufacturers, as they are looking to include lightweight components to make their vehicles more sustainable.
Image and content: Pexels/University of Sheffield