Abstract
The paper deals with the development of strong, tough steels with intrinsic corrosion resistance for structural applications in the Arctic, based on the auto-aging effects of copper and microduplex precipitation of carbides of niobium and titanium. The effects of hot-rolling parameters and aging on the microstructure and mechanical properties of a low-carbon Cu-Ni-er-P-Nb-Ti steel have been studied. Results indicate that: (i) the nature of the matrix has an important influence on the mechanical properties (the microstructures, in order of increasing strength, are ferrite, deformed ferrite, duplex structure, and bainite); (ii) the age-hardening response, in spite of three precipitation-hardening elements, is classical in nature with an activation energy of 163 kJ mol−1 ; (iii) there is considerable scope for developing weathering steels with strength levels in the range 850–1000 MN m−2 with low transition temperatures (−40° to −100°C) based on the precipitation strengthening of copper and combined additions of niobium and titanium.
Get full access to this article
View all access options for this article.