Stainless Steel World magazine recently published a short article about research taking place at the Pohang University of Science and Technology in South Korea where Dr. Sang-Heon Kim, working closely with colleagues, has produced a material with the characteristics of titanium alloys but at considerably less costs. This result had been achieved by manipulating the structure of steel on a nanometre scale. The key breakthrough came with the research team finding a way to increase the aluminum content of the material whilst overcoming the formation of brittle intermetallic compounds.
The group of researchers under Dr. Kim’s leadership demonstrated that an FeAl-type brittle but hard intermetallic compound (B2) can be used as a strengthening phase in high-aluminum low-density steel, while alleviating its harmful effect on ductility by controlling its morphology and dispersion. The steel which the team produced takes advantage of B2’s hardness and austenite’s ductility. By adding nickel and temperature-treating an alloy of iron, aluminum, manganese and carbon, they induced smatterings of B2 to form evenly through the steel. The result is a material in which the hard B2 lattices reinforces the supple austenite matrix, giving it impressive strength.
It is thought that the new alloy could be of considerably significance to the automotive industry where weight is often of paramount importance, for Dr. Kim and his team have calculated that if the weight of a car can be reduced by one-tenth, it can lead to a fuel saving of around 7%. That the breakthrough is regarded as being important can be drawn from the fact that although the new steel is still only at development stage, POSCO, one of the largest steel producers in the world, is planning trials with the material later in 2015 to see if it can provide commercial potential on an industrial scale.