Energy and Environmental Savings by and for Steel Lightweight

The ironmaking and steelmaking industry is one of the heavy polluters responsible for nearly 7% of global carbon dioxide and greenhouse gas (GHG) emissions. Creating new technologies and equipment and renewing the assortment of metallurgy products is compulsory to achieve the goal of climate change prevention. Lightweight and advanced higher-strength steels (AHSS) to replace old mild grades and simultaneously decrease the mass of ready products is one of the efficient ways. Three generations of AHSS of different chemical compositions and properties have already been developed, including lightweight grades alloyed with a high aluminium content. A review of the Life Cycle Assessment (LCA) results proves the energy and environmental efficiency of Advanced High Strength Steels (AHSS) compared with aluminium and HSS for the same purpose structures in vehicles. Using aluminothermic ferroaluminium from secondary materials helps to reduce the cost of lightweight steels with high aluminium content due to the 2-3 times higher assimilation of aluminium by liquid steel at both deoxidation and alloying, which was experimentally proved for HSS grades. Due to less energy consumption at ferroaluminium than secondary aluminium ingots manufacturing, alloying of AHSS (10% wt of Al) by FeAl30 reduces GHG emission for more than 0.384 t CO2-eq per ton of steel.