DOI: https://doi.org/10.22184/1993-8578.2023.16.3-4.208.219

In this article the corrosion behavior was considered and the surface analysis of Ti49.0Ni51.0 alloy samples in various structural (coarse-grained, ultrafine-grained, prepared by equal-channel angular pressing of a quenching sample, and ultrafine-grained after ECAP with preliminary aging) states in acid solutions – HCl and H2SO4. Studies have shown that corrosion damage in solutions of acids of various concentrations (1M, 3M) occurs most intensively in the coarse-grained state with an increased concentration of the acid solution. The formation of an ultrafine-grained structure reduces the corrosion rate; however, the ultrafine-grained state of the pre-aged alloy increases the corrosion rate compared to the unaged state in the sulfuric acid solution.