Hot Deformation Behavior and Dynamic Recrystallization Nucleation Mechanisms of Inconel 625 during Hot Compressive Deformation

Abstract

High‐temperature compression deformation behavior of the Inconel 625 alloy is investigated using hot compression tests. The results regarding the flow behaviors and hot processing map indicate that the optimum condition for plastic deformation is determined to be at temperatures higher that 1050 °C and strain rate from 1 to 10 s−1. Herein, the hot compression microstructure evolution is characterized by electron backscattered diffraction (EBSD) and transmission electron microscopy (TEM) techniques. The results indicate that the dynamic recrystallization (DRX) mechanism is different under different compression deformation conditions. At low temperatures (<1100 °C), continuous dynamic recrystallization (CDRX) with subgrain rotation plays a dominant role in the DRX process. However, as the temperature rises beyond 1100 °C, discontinuous dynamic recrystallization (DDRX) with a bulging boundary induced by twinning becomes dominant in the dynamic recrystallization process. The findings provide a theoretical basis for the optimization of the thermoplastic processing of nickel‐based superalloys.

Deformation Behavior and Microstructural Evolution of Inconel 625 Superalloy during the Hot Compression Process

“…DRX behavior of IN625 alloy fabricated by directed energy deposition has been studied by Hu et al [19], and the results agree well with the results from Ref. [16]. Meanwhile, during the hot spinning process, the deformation temperature and strain rate are both a little lower than that in the above studies, which is in the range of 800-1050 • C and 0.001-1 s −1 , respectively.…”

“…Guo et al [15] developed the microstructural mechanism map for IN625 alloy and found DRX grain growth when the temperature was in the range of 1150-1200 • C and strain rate was in the range of 0.01-0.1 s −1 , and the results also showed that the second-phase particles and carbides can facilitate the DRX processing. Jia et al [16] have studied the DRX nucleation mechanism of IN625 alloy. Conclusions show that the DRX mechanism varies with the deformation temperature, i.e., continuous DRX (cDRX) and discontinuous DRX (dDRX) are dominant under 1100 • C and above 1100 • C, respectively.…”

Nanomechanical Characterization of the Deformation Response of Orthotropic Ti–6Al–4V

“…[11][12][13][14][15][16] Several manufacturing processes among the aforementioned applications contemplate the implementation of material characterization procedures, either on pristine samples of the material or on previously manufactured parts. The most commonly applied experimental procedures to identify the macroscopic orthotropic elastoplastic properties of a material include monotonic tensile, [17,18] compression, [19,20] and shear [21,22] tests of material samples obtained from its orthogonal directions. The main limitations of these tests are the size of the specimens and their subsequent destruction,…”

Effects of Deformation Processing Parameters on the Microstructure Evolution and Microhardness of GH4169 Superalloy during Annealing Treatment

“…[ 19,20 ] The different constitutive models, which are used to accurately forecast flow behaviors of GH4169 superalloy, were, respectively, constructed by Lin et al, [ 21,22 ] Geng et al, [ 23 ] and Chen et al, [ 24 ] To obtain the optimal ranges of hot deformation parameters, the processing maps are developed by Wen et al, [ 25,26 ] Yang et al, [ 27 ] and He et al, [ 28 ] In addition, because of the low stacking fault energy of GH4169 superalloy, [ 29 ] dynamic recrystallization (DRX) is the dominant microstructure evolution mechanism during thermal deformation. Mirzadeh et al, [ 13 ] Pradhan et al, [ 30 ] and Jia et al, [ 31 ] studied the DRX mechanism by analyzing the microstructure evolution of a nickel‐based superalloy during different deformation processes. Similar consequences were also demonstrated by Azarbarmas et al, [ 32 ] who found that the occurrence of DRX can be effectively motivated by reducing strain rate and improving deformation temperature and true strain.…”