Erosion study of final stage blading of low pressure steam turbines

In order to increase our knowledge of erosion phenomena, the Steam Turbine Groupe STG.of ALSTOM has been using an erosion test facility in the C.R.T.V. Centre de Recherche Turbines a` Vapeur.. This test facility simulates erosion in low pressure steam turbine cylinders in order to compare the erosion resistance of various blade materials 12% chromium steel, titanium alloys, etc..and their protection superficial hardening, coatings, etc... This test facility also allows us to understand the mechanism causing damage at a macroscopic level impact energy of the droplets and the loss of eroded volume.and at a microscopic level residual stress and metallurgic analysis.and therefore to determine an evolution law of material surface damage. In this paper, the behaviour of the materials 12% chromium steel and titanium alloys., which has been analysed by image production measurement methods, will be presented according to different impact velocities. q1999 Elsevier Science B.V. All rights reserved.