Tensile properties and deformation mechanisms of a solution treated Ni-Fe-based alloy at high temperatures

This study investigated the high-temperature tensile properties and deformation mechanisms of a solution treated Ni-Fe-based alloy ranging from 600 to 750 degrees C. The solution treated GH4070P (HT700P) alloy exhibits superior yield strength of 490 MPa and ultimate strength of 593 MPa at 700 degrees C. The major carbides in the alloy are the blocky MC and discrete-distributed M23C6. The MC and M23C6 carbides at the grain boundaries (GBs) can impede crack propagation, yet concurrently intensify the stress concentration. The transgranular and intergranular fractures are observed. Above 700 degrees C, micro-cracks emerge around M23C6 carbides at GBs and then are interlinked to form lengthy secondary micro-cracks, resulting in the intergranular fracture. The precipitation of gamma' precipitates during tension at 700 and 750 degrees C confers the alloy to a higher strength.

Automated summary

This study investigated the high-temperature tensile properties and deformation mechanisms of a solution treated Ni-Fe-based alloy. It was found that the alloy exhibited higher yield strength and ultimate strength at 700 degrees Celsius. The carbides in the alloy can impede crack propagation but also intensify stress concentration. Micro-cracks around carbides at grain boundaries at temperatures above 700 degrees Celsius resulted in intergranular fracture.