Cavitation erosion of a spinodally decomposed wrought duplex stainless steel in a benign environment

This paper looks into the possibility of using spinodal decomposition (SD) to improve the cavitation erosion (CE) resistance of a wrought duplex stainless steel (DSS) in benign environments. The hardness increase of the ferrite associated with SD improves CE resistance of the DSS. Mechanical properties obtained from tensile curves (e.g., tensile toughness and strain-hardening capacity) do not appear to correlate with CE resistance. Grain boundaries are prime initiation sites of CE damage. Planar deformation features are also places where CE damage begins. In both the spinodally-decomposed and the solution-treated states, the ferrite of the DSS sustains more CE damage than does the austenite. The austenite actually acts as barrier to CE damage propagation. •Spinodal decomposition (SD) hardens the ferrite, which raises cavitation erosion resistance (CE) of the duplex steel.•The austenite undergoes nearly no changes on annealing in the SD temperature range, and it impedes CE damage propagation.•The enhancement of CE resistance by SD and the role of austenite are different from the observations made on similar steels.