Laser shock processing on Ni-based superalloy K417 and its effect on thermal relaxation of residual stress

Abstract

The compressive residual stress fields at ambient temperature and stress relaxation at elevated temperatures of nickel-based alloy K417 by laser shock processing (LSP) were investigated by the finite element analysis and experimental method. A temperature and strain rate-dependent plasticity model of Johnson-Cook (JC) material model was utilized to investigate the residual stress evolution under LSP and thermal loads. The residual stress distributions of original and processed specimens were measured by the X-ray diffraction method. Zener-Wert-Avrami function was employed to study the thermal relaxation process of LSP K417, and the simulated results have a significant agreement with the experimental data. Specifically, most of stress relaxation occurs before 30 min of exposure, and the relaxation amplitude increases with the rise of applied temperature. The activation enthalpy of the relaxation process for LSP K417 obtained from simulation and experiment are determined to be 2.86 and 2.85 eV respectively.

Effects of high energy laser peening followed by pre-hot corrosion on stress relaxation, microhardness and fatigue life and strength of single crystal nickel CMSX-4® superalloy

“…The combined effects of thermal and cyclic loading can lead to complex stress relaxation [41][42][43].…”

Study on stress relaxation characteristics of FGH95 powder superalloy treated by laser shock peening

“…The residual stress relaxation process of FGH95 powder superalloy after LSP was analyzed dynamically, and the relaxation rate and related influencing factors were determined by the residual stress temperature relaxation data. As shown in previous literature [6][7][8][9][10], the effect of temperature on residual stress relaxation can be expressed by Zener-Wert-Avrami function:…”

“…There have been relevant reports on the stability of residual compressive stress of nickel-based alloy introduced by LSP [4][5][6][7][8][9][10][11][12][13][14][15]. Chin et al [4] compared and analyzed the thermal relaxation phenomenon of residual stress of Inconel 718 nickel-based alloy after LSP and SP treatment, and the results also showed that the residual stress relaxation rate of SP-treated sample was faster under the condition of thermal exposure.…”

Numerical Simulation on Residual Stress Field of Flat‐Topped Laser Oblique Shocking of Ni‐Based Alloy GH4169

“…Kattoura et al studied the effect of LSP on residual stress, microstructure, and fatigue behavior of ATI 718Plus alloy [14]. Zhou et al analyzed LSP on Ni-based alloy K417 and its effect on thermal relaxation of residual stress [15]. Xianliang Hu et al simulated the surface morphology and residual stress field of the Ni-based alloy IN718 by Gaussian mode laser shock [16].…”

“…Xianliang Hu et al simulated the surface morphology and residual stress field of the Ni-based alloy IN718 by Gaussian mode laser shock [16]. e laser energy distribution in numerical simulation study of LSP mostly adopted the Gaussian beam [15][16][17][18][19][20]. Due to the characteristics of Gaussian beam, the residual stress field in shock area of material would be unevenly distributed, which would affect the uniformity of shock effect.…”