Study on the dynamic recrystallization mechanisms of GH5188 superalloy during hot compression deformation

• Published in: Journal of alloys and compounds Vol. 895; p. 162565
• Main Authors: Liu, Dahai, Chai, Haorui, Yang, Liang, Qiu, Wenqing, Guo, Zhenghua, Wang, Zhilu
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 25.02.2022; Elsevier BV
• Subjects: Compression tests; Dynamic recrystallization; Edge dislocations; Electron backscatter diffraction; Forging; GH5188 superalloy; High strain rate; Hot compression test; Hot pressing; Microstructure; Segmentation; Shear bands; Softening; Superalloys; Yield strength; Hot compression test; GH5188 superalloy; Dynamic recrystallization
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2021.162565

•DDRX is the dominant nucleation mechanism of DRX for GH5188 superalloy deformed at 1080°C.•The twinning played a significant role during the CDRX under high temperature and high strain rate loading conditions.•Grain refinement was observed at a high strain rate and high-temperature loading conditions. In this paper, the flow stress behavior and recrystallization mechanism of GH5188 superalloy were studied based on hot compression tests performed at 1080–1180°C and strain rate of 0.1–10/s. During the forging process, dynamic recrystallization (DRX) behavior was found to be the main softening mechanism of GH5188 superalloy, and significantly affected both the plastic behavior and microstructural evolution. Electron backscattered diffraction results further indicated that discontinuous dynamic recrystallization (DDRX) and continuous dynamic recrystallization (CDRX) were the main softening mechanisms at 1080 and 1180°C, respectively. At the high strain rate of 10/s, twin was mainly generated through the transformation of micro shear bands. Twinning played a key role in the segmentation and rotation of subgrain, and resulted in the refinement of microstructures.