| Popis: |
The article discusses the results of the study of the causes of destruction of the axial compressor blade and the causes of the defect of the working blade 10 stage GTU GPA type GTK-10-4 station No. 18 of the compressor station “Dzhangala”. The blade is made of X20Cr13 steel (AISI 420). The blades have an operating time of 23 284 hours after the last repair. Chemical analysis, fractographic analysis, and hardness measurements were performed. The probable cause of defect formation and destruction of the blade is established. The measured hardness values comply with the standard. А study of the chemical composition of metal blades is not revealed a deviation in the content of the main alloying elements. The results of fractographic analysis showed that the destruction caused the presence of a subsurface defect. The defect is an oxidizing shell of about 9×4 mm in size with propagation in operation to the outer surface. In operation, as a result of corrosion, static and dynamic stresses, a crack was formed in the area of the source with exit to the surface along the input edge of the blade. Non-destructive testing was performed on the remaining blades. No defects detected. On the basis of which it was decided to continue the operation of the working blades of the GTK-10-4 turbine, subject to periodic monitoring. |
