Effect of Pretension on Residual Stress and Mechanical Properties of FGH96 Alloy

Author of the article:ZHOU Xiaoming, ZENG Weihu, WANG Zhibiao, FENG Yefei, WANG Chaoyuan, ZOU Jinwen

Author's Workplace：Key Laboratory of Advanced High Temperature Structural Materials, Beijing Institute of Aeronautical Materials, Beijing 100095, China

Key Words：FGH96 alloy; pretention; residual stress; dislocation

Abstract：The FGH96 alloy tensile specimen at room temperature for 0~4% pre-stretching strain after processing, testing the FGH96 alloy under different pre-stretching strain in-plane strain, surface residual stress and room temperature tensile strength, yield strength and high temperature creep properties, and the different pre-stretching strain after FGH96 alloy microstructure, γ′ phase and dislocation were studied. The results show that, with the increase of pretension strain, the residual stress at each position on the specimen surface decreases gradually, and the decrease of residual stress is greater with the increase of pretension strain. Under the same pretension strain condition, the residual stress of the specimen decreases greatly, which is consistent with the result that the strain field in the specimen shows that the strain at the edge of the specimen is larger. The microstructure and γ′ phase of FGH96 alloy with different pretension strains have no obvious difference. Under the condition of low pre-strain, the second γ′ phase of FGH96 alloy can’t be observed in place. When the pre-strain reaches 2.5%, a small amount of dislocations appear to cut the secondary γ′ phase, and the phenomenon of stacking fault appears. With the increase of pre-tensile strain, the packing path of dislocation at grain boundary increases, and the dislocation entanglement are formed.