In the last decades, low-density steels for forging have increasing interest in the automotive industry, and good mechanical properties are required for their real application. This paper describes the results obtained for a 0.66C11.4Mn9.9Al duplex austenitic low-density steel after applying a set of isothermal treatments at different combinations of time and temperature, aimed to promote kappa carbide precipitation, and improve the mechanical properties obtained with a water quenching treatment. The effects of the different isothermal treatments on the microstructure and on the mechanical properties have been analyzed and compared to those obtained from a quenching heat treatment. We found that isothermal treatments in the range temperature between 550–750 °C promoted the profuse precipitation of coarse kappa carbides at grain boundaries, which dramatically reduced the ductility of the alloy, whereas a traditional quenching treatment resulted in a better combination of ductility and mechanical strength.

This work aimed to develop new S355-based structural steels with enhanced marine corrosion resistance while preserving mechanical properties. Two alloying strategies (Cu/Ni and Al/Cr) were investigated. Conventional and new steel samples were produced and characterized for microstructure, mechanical properties, and corrosion. The new steels showed similar or improved mechanical properties. Potentiodynamic polarization tests indicated stabilization of the oxidation process in the new steels. Laboratory accelerated corrosion tests on painted specimens revealed reduced blistering at paint film defects for some new steels compared to conventional steel. Ongoing research includes evaluating painted specimens in a real offshore environment using an advanced floating laboratory

The optimization of battery electric vehicles requires advanced high-strength steels that combine ductility and toughness, enabling lightweight leaf spring constructions with improved performance. This study investigates processing optimization by comparing the newly developed 45SiCrV9Ni, previously identified as promising for stress peening and fatigue, with the conventional 51CrV4 as a benchmark. Dilatometric, mechanical, and microstructural analyses were conducted in as-supplied and heat-treated conditions. Both steels show excellent high-temperature ductility, making them suitable for hot forming under similar conditions. However, 45SiCrV9Ni requires a higher temperature for homogenized austenitization. After tempering, it consistently exhibits superior hardness and toughness compared to 51CrV4. Importantly, its ductility remains nearly constant over a wide tempering temperature range, allowing lower ones to be chosen without compromising strength or toughness, offering additional energy-saving possibilities. These results highlight the potential of 45SiCrV9Ni for leaf spring applications.