The oxidation behavior of Ni-based superalloy GH4742 exposed to water vapor was investigated at 900-1100℃for 50 h in Ar+20%H_(2)O,with Ar+20%O_(2)included for comparison.The presence of H_(2)O is adverse to formation...The oxidation behavior of Ni-based superalloy GH4742 exposed to water vapor was investigated at 900-1100℃for 50 h in Ar+20%H_(2)O,with Ar+20%O_(2)included for comparison.The presence of H_(2)O is adverse to formation of continuous Cr_(2)O_(3)oxide layer but contributes to generation of big voids.Based on this,Ni^(2+)and Co^(2+)are more easily to diffuse towards the outermost oxide layer(OOL),forming non-protective Ni-and Co-rich oxides with high proportion.This leads to a higher weight gain in Ar+20%H_(2)O than that in Ar+20%O_(2).At elevated temperatures,the spallation of oxide scale occurs while the consumption of Cr is reduced in Ar+20%H_(2)O,and the contents of Ni-and Co-rich oxides at this moment are reduced in the OOL.The oxidation mechanism was also discussed.展开更多
Delayed γ-ray spectroscopy of^(185)Au was studied at the Argonne Gas-Filled Analyzer.A new isomer at an excitation energy of 1504.2(4) keV with a half-life of 630(80) ns was identified via γ-γ coincidence analysis,...Delayed γ-ray spectroscopy of^(185)Au was studied at the Argonne Gas-Filled Analyzer.A new isomer at an excitation energy of 1504.2(4) keV with a half-life of 630(80) ns was identified via γ-γ coincidence analysis,decaying via a 294.8(3) keV transition.Based on Weisskopf estimates,the multipolarity of the 295 keV transition is assigned to be E1,M1,E2,or M2.Possible configurations for this new isomer are discussed based on configurationconstrained potential energy surface calculations.展开更多
基金supported by the National Key R&D Program of China(No.2021YFB3700400)National Natural Science Foundation of China(Nos.52074030,51904021,52174294).
文摘The oxidation behavior of Ni-based superalloy GH4742 exposed to water vapor was investigated at 900-1100℃for 50 h in Ar+20%H_(2)O,with Ar+20%O_(2)included for comparison.The presence of H_(2)O is adverse to formation of continuous Cr_(2)O_(3)oxide layer but contributes to generation of big voids.Based on this,Ni^(2+)and Co^(2+)are more easily to diffuse towards the outermost oxide layer(OOL),forming non-protective Ni-and Co-rich oxides with high proportion.This leads to a higher weight gain in Ar+20%H_(2)O than that in Ar+20%O_(2).At elevated temperatures,the spallation of oxide scale occurs while the consumption of Cr is reduced in Ar+20%H_(2)O,and the contents of Ni-and Co-rich oxides at this moment are reduced in the OOL.The oxidation mechanism was also discussed.
基金Supported by the National Natural Science Foundation of China (12405140, 12135004, 11961141004, U2032138, 12275369)the Natural Science Foundation of Gansu Province, China (24JRRA033)+4 种基金financial support from the STFCfunded by the Chinese Academy of Sciences President's International Fellowship Initiative (2020VMA0017)Supported by the U.S. Department of Energy, Office of Nuclear Physics, (DE-AC02-06CH11357, DE-FG02-94ER41041 (UNC), DE-FG02-97ER41033 (TUNL))supported by the Slovak Research and Development Agency (APVV-22-0282)Slovak Grant Agency VEGA (1/0019/25)。
文摘Delayed γ-ray spectroscopy of^(185)Au was studied at the Argonne Gas-Filled Analyzer.A new isomer at an excitation energy of 1504.2(4) keV with a half-life of 630(80) ns was identified via γ-γ coincidence analysis,decaying via a 294.8(3) keV transition.Based on Weisskopf estimates,the multipolarity of the 295 keV transition is assigned to be E1,M1,E2,or M2.Possible configurations for this new isomer are discussed based on configurationconstrained potential energy surface calculations.
