Erosion–corrosion of stainless steels, titanium, tantalum and zirconium

The observation of in-plant failures of AISI 304L stainless steel and Ta–2.5W alloy, promoted the investigation of the erosion–corrosion behaviour of stainless steels AISI 304L and 316L and highly corrosion resistant reactive or refractory metals such as Ti, Ta and Zr. Erosion–corrosion tests were carried out by immersing the materials in an aqueous solution containing 10 wt% HCl in the presence of α-Al2O3 particles at 1000 rpm for 168 h at room temperature. In each case, pure corrosion and combined erosion–corrosion effects were studied by partially protecting the materials from the impact of solid particles during the tests. While Ta and Zr showed no significant weight or roughness changes, Ti weight loss was one order of magnitude higher than that of Ta and Zr, and the stainless steels suffered severe attack as the oxide layers were removed exposing the base metal. Erosion–corrosion mechanisms were determined from microstructural studies by light and SEM microscopy.