The oxidation behavior (isothermal and cyclic oxidation) of cast superalloy K38G and the effect of Ce^+ ion implantation with dose of 1×10^(17) ions/cm^2 upon its oxidation resistance at 900 and 1000 ℃ in air we...The oxidation behavior (isothermal and cyclic oxidation) of cast superalloy K38G and the effect of Ce^+ ion implantation with dose of 1×10^(17) ions/cm^2 upon its oxidation resistance at 900 and 1000 ℃ in air were investigated. Meanwhile, the influence of Ce^+ implantation on oxidation behavior of K38G with pre-oxide scale at 1000 ℃ in air was compared. The pre-oxidation was performed at 1000 ℃ in static air for 0.25 and 1.5 h, respectively. It is shown that the homogeneous external mixture oxide of rutile TiO_2+Cr_2O_3 and non-continuous internal oxide of Al_2O_3 are formed during the oxidation procedure in all the cases. The isothermal oxidation resistance and the cracking or spallation resistance of superalloy K38G implanted with Ce^+ by both of the two different implantation ways are not improved notably. This may be attributed to the mixed oxide composition characteristics and the blocking effect differences of Ce^+ segregation along the oxide grain boundaries on the transport process for different diffusing ions.展开更多
The sputtered nanocrystalline coating of K38G alloy was obtained by magnetron sput-tering. The hot corrosion behaviors of cast K38G alloy and its sputtered nanocrys-talline coating by pre-deposited 75wt%Na2SO4+25wt%K2...The sputtered nanocrystalline coating of K38G alloy was obtained by magnetron sput-tering. The hot corrosion behaviors of cast K38G alloy and its sputtered nanocrys-talline coating by pre-deposited 75wt%Na2SO4+25wt%K2SO4 at 900℃ were studied. The results indicated the occurrence of internal sulfidation in the cast K38G alloy with pre-deposited sulfattes of 0.8 and 3.0mg/cm2. However, the internal sulfidation was not observed in the coating with pre-deposited 0.8mg/cm2 sulfate. The hot corrosion resistance of K38G alloy was clearly enhanced through nanocrystallinzation, although the internal sulfides were still formed for the coating with sulfate deposit of 3mg/cm2. The relevant hot corrosion mechanism was also discussed.展开更多
基金Project supported by National Outstanding Young Scientist Foundation of China (50371095) the Special Funds for the Major State Basic Research Projects (G19990650) and State Laboratory for Corrosion and Protection of Metals
文摘The oxidation behavior (isothermal and cyclic oxidation) of cast superalloy K38G and the effect of Ce^+ ion implantation with dose of 1×10^(17) ions/cm^2 upon its oxidation resistance at 900 and 1000 ℃ in air were investigated. Meanwhile, the influence of Ce^+ implantation on oxidation behavior of K38G with pre-oxide scale at 1000 ℃ in air was compared. The pre-oxidation was performed at 1000 ℃ in static air for 0.25 and 1.5 h, respectively. It is shown that the homogeneous external mixture oxide of rutile TiO_2+Cr_2O_3 and non-continuous internal oxide of Al_2O_3 are formed during the oxidation procedure in all the cases. The isothermal oxidation resistance and the cracking or spallation resistance of superalloy K38G implanted with Ce^+ by both of the two different implantation ways are not improved notably. This may be attributed to the mixed oxide composition characteristics and the blocking effect differences of Ce^+ segregation along the oxide grain boundaries on the transport process for different diffusing ions.
文摘The sputtered nanocrystalline coating of K38G alloy was obtained by magnetron sput-tering. The hot corrosion behaviors of cast K38G alloy and its sputtered nanocrys-talline coating by pre-deposited 75wt%Na2SO4+25wt%K2SO4 at 900℃ were studied. The results indicated the occurrence of internal sulfidation in the cast K38G alloy with pre-deposited sulfattes of 0.8 and 3.0mg/cm2. However, the internal sulfidation was not observed in the coating with pre-deposited 0.8mg/cm2 sulfate. The hot corrosion resistance of K38G alloy was clearly enhanced through nanocrystallinzation, although the internal sulfides were still formed for the coating with sulfate deposit of 3mg/cm2. The relevant hot corrosion mechanism was also discussed.
