The influence of hot rolling-induced microstructural changes on the mechanical properties and fracture behavior of homogenized Ni-12.5Mo-7.8Cr nickel-base superalloy

Sarvarilale, Morteza; Bakhshi, Sorosh

doi:10.24200/nst.2025.1758.2086

The influence of hot rolling-induced microstructural changes on the mechanical properties and fracture behavior of homogenized Ni-12.5Mo-7.8Cr nickel-base superalloy

Articles in Press

Document Type : Research Paper

Authors

Morteza Sarvarilale

Sorosh Bakhshi

Faculty of member

https://doi.org/10.24200/nst.2025.1758.2086

Abstract

Nickel-based alloys were highly regarded due to their strength and good corrosion resistance at high temperatures. From the group of nickel-based superalloys, the Ni-12.5Mo-7.8Cr alloy has attracted the attention of researchers more than other structural materials due to its low production cost, easy access, excellent weldability, and excellent resistance to hot corrosion. In this research, the microstructural changes caused by hot rolling on the mechanical properties and fracture behavior of Ni-12.5Mo-7.8Cr nickel base superalloy were studied and investigated. For this purpose, hot rolling operation at 1100 °C was performed on the homogenized ingot at 1177 °C for 20 minutes. Microstructural investigations, fracture behavior and mechanical properties were carried out using optical and electron imaging analyzes and tensile tests. Microstructural investigations showed the formation of coarse and fine grains and creation of inhomogeneous structure after the hot rolling process. Also, according to the tensile test results, hot rolling led to an improvement of approximately 120% yield strength and a decrease of approximately 13% in the final tensile strength. Also, the fracture pattern of the homogenized and rolled sample shows the change of the fracture mechanism from soft to grain boundary brittle as a result of hot rolling.

Keywords

Nickel base alloy

high strength

high temperature corrosion resistance

homogenization

hot rolling

twinning

Main Subjects