---

Compressor and their blades are one of the most important parts of gas turbines. Based on recent reports, failure of compressor’s blades was one of the major cause in malfunctioned t56 gas turbines. In this study, propagation rate of a crack within the compressor blade of a T56 jet engine has been investigated. To this end, centrifugal and aerodynamic forces acted upon the blade has been calculated and their corresponding stress field has been simulated in ANSYS software. Spots at the maximum risk of foreign object damage and corrosion had been located, and their bending and tension stresses had been calculated via employed simulation. Subsequently, an initial half elliptical crack has been created on all of previously located spots, and their stress intensity factor using Raju-Newman method has been determined. Finally, by using Paris law fatigue life and crack growth rate of each cracks has been extracted, individually. Results indicate a drastic decrease in fatigue life of blades when crack located close to the blade’s root. Furthermore, cracks located on the suction surface has remarkably shorter fatigue life than those which are located on pressure surface, in comparison.

---

1.4923 stainless steel is one of the options for producing Iranian gas turbine (IGT25) compressor blades and upgrading IGT25 +., as well as the importance of wear resistance in turbine parts and the small number of studies in the field of wear as a destructive mechanism of turbine parts, in this research the effect of residual stress caused by shot peening on the wear resistance of steel 1.4923 was investigated. To create the compressive residual stress, shot peening operations were used at 5, 10, 15 and 20 minutes. Microstructural studies by optical microscopy (OM) and scanning electron microscopy (SEM) showed that with increasing shot peening time, the thickness of the plastic deformation area increases so that the plastic deformation area can be divided into three plastic deformation areas. Severe, ordinary plastic deformation and the area affected by plastic deformation. Calculations on the results of X-ray diffraction (XRD) showed that with increasing shot peening time, the amount of compressive residual stress increases to 694 MPa. With increasing compressive residual stress on the surface, the wear resistance of the samples increased up to 90% due to the increase in the density of dislocations and grain refining.  Also, the investigation of worn surfaces by SEM showed that the wear mechanism in the samples is oxide adhesive wear and increasing the residual stress of the samples causes the transfer of the wear regime to mild wear abrasion with the appearance of crater areas.