Microstructural evolution of inconel 625 during thermal aging

Inconel 625 is due to alloying elements prone to precipitation of different intermetallic phases and secondary carbides during thermal aging. The base of investigation is nickel superalloy Inconel 625 in hot rolled state. Thermal aging was conducted at temperature 650 °C with different duration of treatment for each sample. Microstructural analysis was performed by light microscope and scanning electron microscope. The results of microstructure observation showed the precipitation of intermetallic γ››- Ni3Nb phase in the γ matrix and δ-Ni3Nb phase with M23C6 secondary carbides at the grain boundaries

Evolution of microstructure during hot deformation of INCONEL 625 alloy with different strain rates

Hot compressions tests of Inconel 625 superalloy were conducted using a deformation dilatometer to the strain level of 0,7 at 1 050 °C, with a different strain rate. Optical microscope and electron backscatter diffraction technique were used to investigate the microstructure evolution and nucleation mechanisms of dynamic recrystallization. Microstructural evolution of Inconel 625, deformed to the strain level of 0,7 at 1 050 °C, reveals that the size of the dynamic recrystallization (DRX) grains and the fraction of DRX increase with the decrease in strain rate. At the strain rate 10 s-1, the grain sizes are mainly located in the size below 20 μm, indicating that nucleation of DRX was dominant due to the combined effects of high stored energy and short deformation time for grain growth at high strain rate

Changes in Floristic Diversity Associated with Sheep Grazing Management on a Karst Pasture

Greater plant diversity, richness and lower primary production are more characteristic for karst (calcareous) pastures than for lowland grassland. In relation to the level of animal grazing required, light and moderate levels are usually most appropriate (Hart, 2001). From the conservation point of view grazing intensity should be variable between sites, and between parts of large sites, and timed to provide for the requirements of different species in different seasons (Dolek & Geyer, 2002)

Arsenic accumulation and thiol status in lichens exposed to As(V) in controlled conditions

Thalli of epiphytic lichen Hypogymnia physodes (L.) Nyl. and terricolous Cladonia furcata (Huds.) Schrad., collected from an area with background arsenic concentrations, were exposed to 0, 0.1, 1 and 10 lg mL-1 arsenate (As(V)) solutions for 24 h. After exposure they were kept in the metabolically active state for 0, 24 and 48 h in a growth chamber. In the freeze dried samples glutathione (GSH), glutathione disulphide (GSSG), cysteine (Cys) and cystine were analysed and induction of phytochelatin (PC) synthesis measured by reversed-phase high-performance liquid chromatography in combination with fluorescence detection or UV spectrometry. Total arsenic content in thalli was measured by instrumental neutron activation analysis (INAA). In H. physodes, which contained higher amounts of arsenic compared to C. furcata, total glutathione content significantly decreased in samples exposed to 10 lg mL-1 As(V), whereas in C. furcata a significant increase was observed. In both species PC synthesis was induced in thalli exposed to 10 lg mL-1

Microstructural evolution of inconel 625 during thermal aging

Inconel 625 is due to alloying elements prone to precipitation of different intermetallic phases and secondary carbides during thermal aging. The base of investigation is nickel superalloy Inconel 625 in hot rolled state. Thermal aging was conducted at temperature 650 °C with different duration of treatment for each sample. Microstructural analysis was performed by light microscope and scanning electron microscope. The results of microstructure observation showed the precipitation of intermetallic γ››- Ni3Nb phase in the γ matrix and δ-Ni3Nb phase with M23C6 secondary carbides at the grain boundaries

Evolution of microstructure during hot deformation of INCONEL 625 alloy with different strain rates

Hot compressions tests of Inconel 625 superalloy were conducted using a deformation dilatometer to the strain level of 0,7 at 1 050 °C, with a different strain rate. Optical microscope and electron backscatter diffraction technique were used to investigate the microstructure evolution and nucleation mechanisms of dynamic recrystallization. Microstructural evolution of Inconel 625, deformed to the strain level of 0,7 at 1 050 °C, reveals that the size of the dynamic recrystallization (DRX) grains and the fraction of DRX increase with the decrease in strain rate. At the strain rate 10 s-1, the grain sizes are mainly located in the size below 20 μm, indicating that nucleation of DRX was dominant due to the combined effects of high stored energy and short deformation time for grain growth at high strain rate