Effect of Structural State of Austenitic 15-15 Ti Steel on Initiation and Propagation of Solution-Based Corrosion Attack in Flowing Liquid Pb-Bi Eutectic at 400 and 500 °C

Investigations of corrosion behavior of austenitic 1.4970 (15–15 Ti) steel in Pb-Bi eutectic at 400–550 °C show an effect of structural state of material with identical composition on the depth of solution-based attack. Structural boundaries play a role of active paths along which the solution-based liquid-metal attack develops preferentially. In this view it is important to have quantitative and qualitative information about grain boundary type distribution in material and state of boundaries with respect to the accumulated strains. The EBSD analysis performed on 1.4970 steel in solution-annealed and cold-worked (40% reduction) states indicates that deformation increases substantially the total length of strained boundaries. The increase in fraction of active diffusion paths results in acceleration of corrosion attack on steel via solution.