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Noraziana Parimin
Preferred name
Noraziana Parimin
Official Name
Noraziana, Parimin
Alternative Name
Parimin, N.
Noraziana, Parimin
Main Affiliation
Scopus Author ID
55955288500
Researcher ID
GCS-3360-2022
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1 - 3 of 3
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PublicationEffect of heat treatment on isothermal oxidation of Fe-33Ni-18Cr alloy at 1000°CThis research study was focused on the effect of heat treatment on the isothermal oxidation of Fe-33Ni-18Cr alloy at 1000 °C. The Fe-33Ni-18Cr alloy was undergone heat treatment at three different temperatures, namely 1000 °C, 1100 °C and 1200 °C for 3 hours soaking time followed by water quench to vary the grain size of the alloy. The heat-treated alloys was prepared for further isothermal oxidation test. The heat-treated alloys was ground by using several grit of silicon carbide papers as well as weighed by using analytical balance and measured by using Vernier caliper before the oxidation test. The heat-treated Fe-33Ni-18Cr alloys was isothermally oxidized at 1000 °C for 150 hours exposure time. The characterization of the oxidized samples was carried out using optical microscope and scanning electron microscope (SEM). The heat treatment result shows that, increasing the heat treatment temperature was increased the average grain size of the alloy. The kinetics of oxidation was followed the parabolic rate law which represent the diffusion-controlled oxide growth rate. Fine grain structure of 1000i-1000 sample shows minimum weight gain and lower oxidation rate compared to samples of 1000i-1100 and 1000i-1200. On the other hand, 1000i-1100 and 1000i-1200 samples indicate the formation of oxide spallation and crack propagation on the oxidized surface, respectively.
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PublicationRole of alloyed niobium on the isothermal oxidation of Fe-40Ni-24Cr alloyFe-40Ni-24Cr alloy is the heat-resistant alloy usually use at high temperature service. The alloying elements normally added to the alloy to enhance the resistance to severe oxidation during service. The Fe-40Ni-24Cr alloy was experienced a high temperature oxidation at 700 °C for 500 h exposure time in laboratory air. The discontinuous isothermal oxidation test was carried out at different time intervals to record the weight change of the oxidized alloy throughout the experiment. The oxidized Fe-40Ni-24Cr alloy was characterized in terms of oxidation kinetics, phase analysis by using x-ray diffraction (XRD) technique and oxide surface morphology determination by using scanning electron microscope (SEM) equipped with energy dispersive x-ray (EDX) spectrometer. The oxidation kinetics of oxidized Fe-40Ni-24Cr alloy was exhibited a weight gain trend. The calculation of oxidation rate law was proved that this oxidized Fe-40Ni-24Cr alloy was obeyed parabolic rate law indicating the growth of oxide scales was followed a diffusion-controlled mechanism. The phase analysis of the oxidized Fe-40Ni-24Cr alloy recorded the formation of several oxide phases consists of Cr-rich, Fe-rich, Ti-rich, Nb-rich and spinel oxides structure. These oxides were served as a protective barrier between base metal and environment. The surface morphology of oxide scale after different exposure displayed a continuous oxide layer formed on the alloy surface with evidence of overgrown Nb-rich oxide particle at discrete area on the alloy surface starting from 150 h exposure time.
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PublicationIsothermal oxidation behavior of Fe-33Ni-18Cr alloy in different heat treatment temperatureThis research study describes the influence of different heat treatment temperature on isothermal oxidation of Fe-33Ni-18Cr alloy. The Fe-33Ni-18Cr alloy was undergone heat treatment at three different temperatures, namely 1000 °C, 1100 °C and 1200 °C for 3h soaking time followed by water quench to vary the grain size of the alloy. This alloy was ground by using several grit of silicon carbide papers as well as weighed by using analytical balance and measured by using Vernier caliper before oxidation test. The heat-treated Fe-33Ni-18Cr alloy was isothermally oxidized at 800 °C for 150h. The characterization of oxidized samples was carried out using optical microscope, scanning electron microscope equipped with energy dispersive x-ray (SEM-EDX) and x-ray diffraction (XRD). The results showed that, increasing the heat treatment temperature was increased the average grain size. The kinetics of oxidation followed the parabolic rate law which represents diffusion-controlled oxide growth rate. Fine grain structure of 1000 °C sample shows minimum weight gain and lower oxidation rate compared to samples of 1100 °C and 1200 °C that indicated oxide spallation and porous structure. Besides, phase analysis showed that the oxidized sample formed several oxide phases.