Experimental investigation of fatigue crack growth behavior of GH2036 under combined high and low cycle fatigue

• Establish a novel test rig for specimens under combined high and low cycle fatigue loading.
• Investigate the fatigue crack growth behavior of GH2036 under pure LCF and CCF loadings at 550 °C.
• Gain the fractography of the specimens through SEM observations.

Fatigue crack growth rates have been experimentally determined for the superalloy GH2036 (in Chinese series) at an elevated temperature of 550 °C under pure low cycle fatigue (LCF) and combined high and low cycle fatigue (CCF) loading conditions by establishing a CCF test rig and using corner-notched specimens. These studies reveal decelerated crack growth rates under CCF loading compared to pure LCF loading, and crack propagation accelerates as the dwell time prolongs. Then the mechanism of fatigue crack growth at different loadings has been discussed by using scanning electron microscope (SEM) analyses of the fracture surface.