Engineers at the University of Sheffield came up with new breakthrough steel manufacturing process that promises to reduce CO2 emissions from the car industry.
A team led by Professor Mark Rainforth and Dr. Junheng Gao from the University’s Department of Materials Science and Engineering published a study in the journal Nature that highlights a completely developed new way of making lightweight, high strength steel that can be easily adapted for mass manufacturing.
The team’s research had demonstrated a high improvement in mechanical properties from the development of ultra fine grained steel. The technique promises to produce steel of strength nearly 2GPa which means- for example a 1cm diameter wire is capable of holding a weight of 15 tonnes. At the same time, the steel has high elongation of 45 percent which means that it would be ductile enough to take complex shapes.
This was achieved by the inclusion of copper – an element which is usually avoided in steel production due to its detrimental effect with respect to quality and properties.
The percentage of Copper is increasingly being found in recycled steels because much of it is made using recycled cars and other engineered items that contain electrical wiring and with steelmakers looking to become more sustainable by incorporating more recycled materials in their production process, exclusion of copper from steel has become unavoidable.
To overcome this issue, the Sheffield team has developed a new technique to use copper in the manufacturing process by understanding copper atoms distribution within the steel matrix.
Advanced imaging by co-authors at the U.S. National Institute of Standards and Technology (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, which restricts the growth of grains in the material’s microstructure. This helps in the formation of an ultrafine-grained microstructure responsible for high strength and improved ductility along with enhanced thermal stability.
Application of these high strength steels means less usage of material which implies reduced total weight of components for the same level of performance.
Properties like lightweight and high strength can be utilized by the automobile industries which are looking to reduce weight for improved fuel efficiency. This in turn will reduce carbon footprint making them more sustainable. The average car uses around 900 kg of steel and a decrease in weight will ultimately contribute towards the formation of a greener society owing to lesser environmental impact.
