Residual Stress Distribution of Non-Uniform Quenching in Al-Zn-Mg-Cu Aluminum Alloy Thick Plate

Abstract

Effect of multi-section linear non-uniform heat transfer coefficient on quenching residual stress distribution in 27mm-thick Al-Zn-Mg-Cu aluminum alloy plate was simulation studied by using the finite element method, and the surface quenching residual stress distribution was measured by the X-ray diffraction method and hole-drilling method. The results show that the surface quenching residual stress represents the same distribution with non-uniform heat transfer coefficient in the transverse direction and the stress level maintains initial stress level of the heat transfer coefficient at each location. The distribution of the quenching residual stress in the center of the plate is approximately uniform and the stress level is approximately equal to average of maximum and minimum initial stress level. The measured surface quenching residual stress shows a wavy distribution in the transverse direction, which is similar to the simulated surface stress distribution without considering the stress level. The measurement results can be explained by the multi-section linear non-uniform quenching model.

Residual Stress Distribution of Asymmetric Quenching in Al-Zn-Mg-Cu Aluminum Alloy Plate

“…A series of average heat transfer coefficients were used in this study to quantitatively simulate the asymmetric distribution of heat transfer coefficients on the surfaces of the hardened plate. The average heat transfer coefficients are 26,000 (20˚C), 20,500 (40˚C), 17,500 (60˚C) and 9500 (80˚C) W•m −2 •K −1 , which are taken from the literature [13]. Two asymmetric heat transfer coefficient distribution strategies were implemented in this study to reveal the residual quenching stress distributions under the asymmetric quenching process.…”

“…The material properties of the Al-Zn-Mg-Cu aluminum alloy used in the FEM analysis were obtained by experimental tests and are described in ref. [13]. A 1/8 model of the plate was used to reduce the simulation time by considering the symmetry characteristic of the plate.…”

Prediction of residual stress field on the surface of quenched 7055 aluminium alloy plates

“…The temperature of the water was 20 °C. The thermal and mechanical properties of 7055 aluminium alloy [27] were shown in table 1 and a 1/8 model of the plate was used due to the symmetry feature of the plate. The model used in the simulation is illustrated in figure 4(a) and the studied path is shown in figure 4(b).…”