Influence of Shear Stress on Erosion–Corrosion of Stainless Steels in Simulated Mine Water

This study provides information on the performance of three stainless steels at various shear stresses and presence of silica sand particles in simulated mine water. The materials employed were two duplex stainless steels (UNS S32205 and UNS S32750) and one austenitic stainless steel (UNS 30403). The rotating cylinder electrode system produced shear stresses to evaluate the flow-induced and erosion–corrosion tests by open-circuit potential and potentiodynamic polarization techniques. Hardness tests were used to examine the performance of the degraded samples, and scanning electron microscopy was used to characterize the surface morphology. UNS S32750 displayed nobler OCP compared with UNS S32205 with austenitic steel having the least potential irrespective of the shear stresses and with/without silica sand. Work hardening of the duplex stainless steels promoted variable behavior in the hardness results. The current density results revealed that UNS S32705 had the best corrosion performance in the studied environments. The SEM images showed plastic deformation, material dissolution and pitting corrosion as the shear stress increased and on the introduction of silica sand.