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In this paper the effect of several parameters, such as temperature, time of immersion, cerium ions and hydrogen peroxide concentration, pH of the conversion solution, on the composition and morphology of the conversion layer are investigated as well as on its corrosion resistance in chloride environments. The cerium-based chemical conversion coatings ennobles the corrosion potential and inhibits both the cathodic and anodic reactions rate. Using a cerium (III) chloride solution a not homogeneous coating is obtained and agglomerates with a "dry-mud" morphology of mixed cerium-aluminium oxide are deposited above the cathodic intermetallic particles, while using a cerium (III) nitrate solution the coating is more uniform but thinner than that obtained with cerium (III) chloride. Solution temperature below 50 8C and time of immersion of 10 minutes produces a coating with better corrosion resistance.

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Electric arc furnace (EAF) slag is a by-product of steel production in electric arc furnaces. Several studies have tried to demonstrate its suitability in civil engineering application, such as in bituminous mixtures and cementbased materials, due to its good physical, chemical and mineralogical properties. Particularly the re-use as coarse aggregate for concrete production has been shown to be a promising valorisation, when physical and chemical stability is guaranteed. Additionally, EAF slag's high mechanical strength makes it suitable for high-performance concrete production. In this work three EAF concretes, with various cement content and also with silica fume addition, were compared with a reference concrete, to identify a convenient mix design to reach a concrete strength class between C50/60 and C60/75. Mechanical strength was evaluated analysing compressive and tensile strength, and elastic modulus. A complementary microstructural analysis was performed after the failure of the specimens, with the aim of analysing the morphology of the interfacial transition zone. Results indicate that the use of EAF slag in concrete allows reaching higher compressive strength than with coarse natural aggregates. EAF slag application in structural concrete promotes also the reduction of cement content in the mix to reach the same strength class.

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