In this paper, the isothermal oxidation kinetics and oxidation behavior of GH586 superalloy from 800 to 1000℃ were investigated. The oxide scale morphologies of the surfaces and the cross sections after oxidation wer...In this paper, the isothermal oxidation kinetics and oxidation behavior of GH586 superalloy from 800 to 1000℃ were investigated. The oxide scale morphologies of the surfaces and the cross sections after oxidation were characterized by means of X-ray diffraction （XRD） and scanning electron microscope （SEM） equipped with energy-dispersive spectroscopy （EDS）. The results show that the growth of the oxide scales on the surface of superalloy GH586 obeys a parabolic law with the activa- tion energy of 241.4 kJ.mo1-1 from 800 to 1000℃ The dense oxide scale formed at 800℃ is mainly composed of Cr203, NiCr204 and a small amount of TiO2. At 900℃, the oxide scale is divided into two layers： the outer layer with multiple cracks is mainly composed of ＂Cr203 and TiO2, while the inner is a layer of dense Cr203. Under the oxide scale, aluminum-rich oxides along the grain bound- aries are generated by the internal oxidation. At 1000 ℃for 100 h, cracks throughout the whole oxide film accel- erate the oxidation rate of Ni-based superalloy GH586 and large blocks of TiO2 in the oxide scale are generated, resulting in the spallation of oxide scale.展开更多
基金financially supported by the National Natural Science Foundation of China (No.51641102)the Natural Science Foundation of Jiangsu Province (No.16KJB430035)the Nantong Science and Technology Project (No. GY12015032)
文摘In this paper, the isothermal oxidation kinetics and oxidation behavior of GH586 superalloy from 800 to 1000℃ were investigated. The oxide scale morphologies of the surfaces and the cross sections after oxidation were characterized by means of X-ray diffraction （XRD） and scanning electron microscope （SEM） equipped with energy-dispersive spectroscopy （EDS）. The results show that the growth of the oxide scales on the surface of superalloy GH586 obeys a parabolic law with the activa- tion energy of 241.4 kJ.mo1-1 from 800 to 1000℃ The dense oxide scale formed at 800℃ is mainly composed of Cr203, NiCr204 and a small amount of TiO2. At 900℃, the oxide scale is divided into two layers： the outer layer with multiple cracks is mainly composed of ＂Cr203 and TiO2, while the inner is a layer of dense Cr203. Under the oxide scale, aluminum-rich oxides along the grain bound- aries are generated by the internal oxidation. At 1000 ℃for 100 h, cracks throughout the whole oxide film accel- erate the oxidation rate of Ni-based superalloy GH586 and large blocks of TiO2 in the oxide scale are generated, resulting in the spallation of oxide scale.
