| 2008 №07 (08) | 2008 №07 (01) |
The Paton Welding Journal, 2008, #7, 41-43 pages
Analysis of the causes of fracture of blades in axial-flow compressor of unit GTK-25I
K.A. Yushchenko1, V.S. Savchenko1, L.V. Chervyakova1, V.I. Izbash2, V.G. Solyanik2
1E.O. Paton Electric Welding Institute of the NASU. 11 Kazymyr Malevych Str., 03150, Kyiv, Ukraine.2National Joint Stock Company «Neftegaz Ukrainy», Ukrtransgaz, Kiev, Ukraine
Abstract
The causes of fracture of martensitic-ferritic steel blades in inlet rotary distributor of axial-flow compressor of the gas-pumping unit were studied. Fracture of the blades occurs in several stages: formation of corrosion sites, initiation and propagation of cracks within the zone of corrosion damage under cyclic loading, and fracture. At the initial stage, corrosion damage takes place at the martensite--ferrite interface, after which it develops from intergranular into intragranular corrosion fracture along the martensite needles, and then into fatigue fracture through the bulk of grain.
Keywords: gas turbine units, blades, high-alloy steel, fatigue-corrosion damage
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