The morphology evolution of Al9(Mn,Ni)2 eutectic phase in Al-4 Ni-2 Mn alloy at 350 °C was examined. Two kinds of morphology evolution trends of Al9(Mn, Ni)2 eutectic phase were observed by using scanning electro...The morphology evolution of Al9(Mn,Ni)2 eutectic phase in Al-4 Ni-2 Mn alloy at 350 °C was examined. Two kinds of morphology evolution trends of Al9(Mn, Ni)2 eutectic phase were observed by using scanning electron microscopy and transmission electron microscopy. The ribbon-like Al9(Mn, Ni)2 eutectic phase taking up a small portion of the eutectic structures gradually changes from ribbon-like morphology to rod-like during the heat treatment. The rod-like Al9(Mn, Ni)2 eutectics, primary eutectic structure in the alloy, become unstable at the transverse subboundaries of the eutectic rod when the samples are heat treated at 350 °C, and then split up into short rods with the extension of heat treatment time. Also, the Vickers microhardness test was used to characterize the change of local mechanical properties. The hardness test results indicate that local morphology evolution of eutectic phase has no obvious effect on the local mechanical properties of the alloy. The microhardness of the eutectic area increases slightly when the heat treatment time is extended to 192 h or 360 h.展开更多
The effect of electroslag remelting（ESR） on carbides in 8Cr13MoV martensitic stainless steel was experimentally studied. Phases precipitated from liquid steel during solidification were calculated using the Thermo-C...The effect of electroslag remelting（ESR） on carbides in 8Cr13MoV martensitic stainless steel was experimentally studied. Phases precipitated from liquid steel during solidification were calculated using the Thermo-Calc software. The carbon segregation was analyzed by original position analysis（OPA）, and the carbides were analyzed by optical microscopy（OM）, scanning electron microscopy（SEM）, energy-dispersive X-ray spectroscopy（EDS） and X-ray diffraction（XRD）. The results indicated that more uniform carbon distribution and less segregation were obtained in the case of samples subjected to the ESR process. After ESR, the amount of netty carbides decreased significantly, and the chromium and vanadium contents in the grain-boundary carbides was reduced. The total area and average size of carbides were obviously smaller after the ESR process. In the sample subjected to ESR, the morphology of carbides changed from lamellar and angular to globular or lump, whereas the types of carbides did not change; both M23C6 and M7C3 were present before and after the ESR process.展开更多
文摘The morphology evolution of Al9(Mn,Ni)2 eutectic phase in Al-4 Ni-2 Mn alloy at 350 °C was examined. Two kinds of morphology evolution trends of Al9(Mn, Ni)2 eutectic phase were observed by using scanning electron microscopy and transmission electron microscopy. The ribbon-like Al9(Mn, Ni)2 eutectic phase taking up a small portion of the eutectic structures gradually changes from ribbon-like morphology to rod-like during the heat treatment. The rod-like Al9(Mn, Ni)2 eutectics, primary eutectic structure in the alloy, become unstable at the transverse subboundaries of the eutectic rod when the samples are heat treated at 350 °C, and then split up into short rods with the extension of heat treatment time. Also, the Vickers microhardness test was used to characterize the change of local mechanical properties. The hardness test results indicate that local morphology evolution of eutectic phase has no obvious effect on the local mechanical properties of the alloy. The microhardness of the eutectic area increases slightly when the heat treatment time is extended to 192 h or 360 h.
基金financially supported by the National Natural Science Foundation of China (No. 51444004)China Postdoctoral Science Foundation (No. 2014M560047)
文摘The effect of electroslag remelting（ESR） on carbides in 8Cr13MoV martensitic stainless steel was experimentally studied. Phases precipitated from liquid steel during solidification were calculated using the Thermo-Calc software. The carbon segregation was analyzed by original position analysis（OPA）, and the carbides were analyzed by optical microscopy（OM）, scanning electron microscopy（SEM）, energy-dispersive X-ray spectroscopy（EDS） and X-ray diffraction（XRD）. The results indicated that more uniform carbon distribution and less segregation were obtained in the case of samples subjected to the ESR process. After ESR, the amount of netty carbides decreased significantly, and the chromium and vanadium contents in the grain-boundary carbides was reduced. The total area and average size of carbides were obviously smaller after the ESR process. In the sample subjected to ESR, the morphology of carbides changed from lamellar and angular to globular or lump, whereas the types of carbides did not change; both M23C6 and M7C3 were present before and after the ESR process.
