Metallurgical Analysis and Simulation of a Service-Fractured Compressor Blade Made of ASTM S45000 Alloy

Blades are key components of gas turbine compressors which are frequently subjected to centrifugal and vibratory loads. These cyclic loadings result in degradation of physical and mechanical properties of the blades. Moreover, the blades operate at high temperature and in aggressive environments which makes monitoring their properties hard, and as a consequence their useful life service is limited. In order to prevent early and sudden failure of compressor blades, it seems rational to find out the reason for limited service life of the blades. Experimental and metallurgical investigations on a service-fractured compressor blade combined with blade simulation and stress analysis resulted in calculation of cycles for fatigue crack initiation and propagation and understanding of the sudden failure of the blade made of custom 450 alloy in this case study during service.