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Sulphuric acid (H2SO4) is widely used in various industrial processes, including fertilizer production. However, its highly corrosive nature poses a significant challenge to the materials used for transport and storage, particularly metals and alloys. This review provides an overview of corrosion types in iron and nickel-based alloys, commonly employed for handling sulphuric acid. The paper discusses alloy selection based on their corrosion behavior in different H2SO4 concentrations, temperatures, and harsh conditions such as erosion-corrosion and presence of contaminants. Additionally, it highlights the use of inhibitors and polymeric coatings for corrosion protection. Finally, the paper outlines future research directions for corrosion protection of alloys in sulphuric acid environments.

This study aims at understanding the effect of different heat treatments on the evolution of the microstructure of several Cr–W–V–Mo steels having different compositions and how this latter affects their abrasion resistance. The investigation also gives insights on the formation and effect of core-shell carbides on the abrasion resistance. The commercial highly alloyed stainless steel HCx® and six newly designed Cr–W–V–Mo steels were subjected to three heat treatments: austenitizing at 900 °C and 1100 °C and subsequent quenching, and an ageing treatment at 700 °C. The microstructural analysis demonstrated the formation of Laves phase when austenitizing at 900 °C; this phase is depleting the matrix from carbide forming elements without any improvement in the wear behavior of the alloys. However, increasing the austenitization temperature to 1100 °C favored the development of core-shell carbides that contribute to increase the abrasion resistance of the alloys. The ageing treatment promoted the precipitation of secondary carbides uniformly distributed along the matrix, and they were found to have a beneficial effect on maintaining the good abrasion resistance even after subjecting the steels to a high ageing temperature (700 °C) for long duration (10 h).