A systematic erosion-corrosion study of two stainless steels in marine conditions via experimental design

Erosion-corrosion performance of two stainless steels (UNS S32760 and UNS S31603) for marine applications has been assessed under liquid-solid impingement conditions in 3.5% NaCl. The total material loss rate and the components of mechanical erosion, electrochemical corrosion and their synergistic interactions have been determined under various conditions. The major environmental parameters considered are solid loading, flow velocity and fluid temperature. For the two stainless steels, a quantitative analysis of the damage showed mechanical erosion to be the dominant process under erosion-corrosion over the range of conditions considered. A full two-level factorial experimental design method was applied to study the individual effects of each parameter as well as their interactive contributions to the overall material degradation. The analysis shows that the interactions between environmental factors all accelerate mass loss during the erosion-corrosion process and the interactive effect between velocity and sand loading is the greatest. Fluid temperature has the smallest effect of the three parameters. Some guidelines to assist in material selection for erosion-corrosion and progress towards prediction of erosion-corrosion in marine applications are discussed in this paper. (C) 2007 Elsevier B.V. All rights reserved.