The Research on Recrystallization Behaviors and Mechanism of a Medium-Density Ni-Based Alloy

Abstract

Revealing the recrystallization behavior and mechanism of this new alloy is of great significance to subsequent research. In this study, the Ni-36.6W-15Co ternary medium heavy alloy was solution-treated at 1100–1200 °C for different lengths of time. The grain size change, microstructure and texture evolution as well as twin development during recrystallization annealing were analyzed using SEM, EBSD and TEM techniques. The study found that complete recrystallization occurs at 1150 °C/60 min. In addition, it takes a longer amount of time for complete recrystallization to occur at 1100 °C. The value of the activation energy Q1 of the studied alloys is 701 kJ/mol and the recrystallization process is relatively slow. By comparing the changes of microstructure and texture with superalloys, it is found that the recrystallization mechanism of the studied alloy is different from that of the superalloy. The development of annealing twins has a great influence on the recrystallization behavior and mechanism. The results show that the twin mechanism is considered as the dominant recrystallization mechanism of the studied alloy, although the formation and development of sub-grains appear in the early stage of recrystallization.

Determining the Hot Workability and Microstructural Evolution of an Fe-Cr-Mo-Mn Steel Using 3D Processing Maps

“…Fe-Cr-Mo-Mn steels exhibit exceptional strength, excellent hardenability, superior fatigue resistance, and remarkable impact toughness at low temperatures, and they are capable of withstanding alternating loads [ 1 , 2 , 3 , 4 ], making them extensively utilized in wind power, nuclear energy, and other industries [ 5 , 6 , 7 ]. Hot forging is the most widely used method for the fabrication of steel-based components, and it has characteristics of a high production efficiency and good product quality [ 8 , 9 ]. However, billets are susceptible to cracking and other issues during this process.…”