Isothermal Oxidation Behavior of Fe-33Ni-18Cr Alloy in Different Heat Treatment Temperature

2020 ◽  
Vol 1010 ◽  
pp. 46-51
Author(s):  
Zahraa Zulnuraini ◽  
Noraziana Parimin
Keyword(s):  
Heat Treatment ◽  
Grain Size ◽  
Heat Treatment Temperature ◽  
Minimum Weight ◽  
Isothermal Oxidation ◽  
Optical Microscope ◽  
Treatment Temperature ◽  
Grain Structure ◽  
X Ray ◽  
Average Grain Size

This 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.

Effect of Heat Treatment on Isothermal Oxidation of Fe-33Ni-18Cr Alloy at 1000°C

2020 ◽  
Vol 1010 ◽  
pp. 9-14
Author(s):  
Zahraa Zulnuraini ◽  
Noraziana Parimin
Keyword(s):  
Heat Treatment ◽  
Grain Size ◽  
Minimum Weight ◽  
Isothermal Oxidation ◽  
Optical Microscope ◽  
Grain Structure ◽  
Treatment Result ◽  
Oxidation Test ◽  
Heat Treated ◽  
Average Grain Size

This 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.

Effect of Heat Treatment on the Isothermal Oxidation of Fe-33Ni-19Cr Alloy

2018 ◽  
Vol 280 ◽  
pp. 237-242 ◽  
Author(s):  
Noraziana Parimin ◽  
Z. Zulnuraini ◽  
S.A. Che Sakdun
Keyword(s):  
Heat Treatment ◽  
Grain Size ◽  
Minimum Weight ◽  
Isothermal Oxidation ◽  
Boundary Area ◽  
Heat Treated Sample ◽  
X Ray ◽  
Fine Grain ◽  
Heat Treated ◽  
Average Grain Size

This research investigates the effect of heat treatment on the isothermal oxidation behaviour of Fe-33Ni-19Cr alloy. The samples were undergone heat treatment at three different temperatures namely, 1000oC, 1100oC and 1200oC for 120 minutes of soaking time followed by water quench to differ the grain size of alloy. The heat-treated sample was ground by using SiC paper atP600 finished. The samples were weighed using analytical balance and the surface area was measured before oxidation test. The heat-treated Fe-33Ni-19Cr alloys were isothermally oxidized at 850oC for 150 hours. The characterization on oxidized samples were carried out using scanning electron microscope equipped with energy dispersive x-ray (SEM-EDX) and x-ray diffraction (XRD). The result shows that, the average grain size increases as the heat treatment temperature increased. Fine grain size develops higher grain boundary area which acts as an ion diffusion path across the metal-gas interface during oxide formation. HT1000 sample with fine grain structure shows minimum weight gain and low oxidation rate compared to HT1100 and HT1200 samples. Uniform oxide layerformed on surface of the fine grain size sample. Whereas spallation of oxide scales was identified on the coarse grain size sample. Phase analysis shows that the oxidized sample formed several oxide phase.

Effect of Solution Treatment Temperature on the Microstructure of Fe-33Ni-19Cr Alloy

2020 ◽  
Vol 1010 ◽  
pp. 21-27
Author(s):  
Noraziana Parimin ◽  
Esah Hamzah
Keyword(s):  
Grain Size ◽  
Solution Treatment ◽  
Optical Microscope ◽  
Treatment Temperature ◽  
Solution Treatment Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solution Treated ◽  
Average Grain Size ◽  
Different Temperatures

The effect of solution treatment temperature on the microstructure, phase present and hardness on Fe-33Ni-19Cr alloy was study in this work. The Fe-33Ni-19Cr alloy was experienced a solution treatment process at six different temperatures which are 950 °C, 1000 °C, 1050 °C, 1100 °C, 1150 °C and 1200 °C for 3 hours soaking time followed by water quench. The average grain size was measured by using linear intercept methods ASTM E112. Microstructure of solution-treated Fe-33Ni-19Cr alloy was characterized by using optical microscope and scanning electron microscope (SEM) equipped with energy dispersive x-ray (EDX) spectrometer. The phase present was analyzed using x-ray diffraction (XRD) technique. The Vickers hardness was used to measure the hardness of solution-treated Fe-33Ni-19Cr alloy. Increasing the solution treatment temperatures were increase the average grain size of solution-treated Fe-33Ni-19Cr alloy. In addition, all samples exhibited an equiaxed matrix grain with slight distribution of precipitates particles. The hardness of solution-treated Fe-33Ni-19Cr alloy was decrease as the solution treatment temperature increase.

Improvement of Strength and Ductility by Combining Static Recrystallization and Unique Heat Treatment in Co-20Cr-15W-10Ni Alloy for Stent Application

2021 ◽  
Vol 1016 ◽  
pp. 1503-1509
Author(s):  
Kosuke Ueki ◽  
Soh Yanagihara ◽  
Kyosuke Ueda ◽  
Masaaki Nakai ◽  
Takayoshi Nakano ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Grain Size ◽  
Static Recrystallization ◽  
High Strength ◽  
Small Variation ◽  
Grain Structure ◽  
Fine Grain ◽  
High Temperature Short Time ◽  
Average Grain Size ◽  
Strength And Ductility

The Co-20Cr-15W-10Ni (CCWN, mass%) alloy has excellent corrosion resistance and strength-ductility balance and is applied in almost all balloon-expandable stent platforms. To further reduce the invasiveness of stent placement, it is necessary to reduce the diameter of the stent. That is, both high strength and high ductility should be achieved while maintaining a low yield stress. In our previous studies, it was discovered that low-temperature heat-treatment (LTHT) at 873 K improves the elongation of the CCWN alloy. In this study, we focused on the grain refinement by swaging and static recrystallization to improve the strength of the alloy. The as-swaged alloy was recrystallized at 1373–1473 K for 100–300 s, followed by LTHT. A fine grain structure with an average grain size of 3–17 μm was obtained by static recrystallization. The η-phase (M12X-M6X type precipitates, M: metallic elements, X: C and/or N) formed during the recrystallization at 1373–1448 K. The alloys recrystallized at 1448 and 1473 K had a homogeneous structure with a small variation in the grain size. On the other hand, the alloys recrystallized at 1373 and 1423 K had an inhomogeneous structure in which fine and coarse grains were mixed. Both the strength and ductility of the CCWN alloy were improved by combining high-temperature short-time recrystallization and LTHT.

Grain Structure and Surface Roughness of Four Commercial NiTi Orthodontic Archwires

2017 ◽  
Vol 266 ◽  
pp. 257-263
Author(s):  
Wassana Wichai ◽  
Rutchadakorn Isarapatanapong ◽  
Niwat Anuwongnukroh ◽  
Surachai Dechkunakorn
Keyword(s):  
Surface Roughness ◽  
Grain Size ◽  
Optical Microscope ◽  
Grain Structure ◽  
Wire Surface ◽  
Average Grain Size ◽  
Electron Mode ◽  
The Mean ◽  
The Wire ◽  
Orthodontic Archwires

This study investigated four commercially available NiTi orthodontic archwires from different manufactures for their grain structure and surface roughness.Four commercially available pre-formed NiTi orthodontic archwire (Ormco, Sentalloy, Highland and NIC) with diameter 0.016 x 0.022 inch2 were tested. The wire samples were polished and etched to evaluate the morphology and structure of wire surface. Each NiTi archwire was investigated under a reflected light microscope of an Optical Microscope to analyze its grain structure and size, in longitudinal surfaces. The surfaces of wire were qualitatively examined in the secondary electron mode at common magnification (500X). The surface roughness was also evaluated by a surface roughness tester. The descriptive statistic was evaluated the mean and standard deviation of surface roughness and Medcale T-Test was to test the mean difference of the surface roughness in each brands. This study showed an average grain size of 2-8 μm for each NiTi archwire. The wire surface of Ormco and Highland showed straiations along the longitudinal axes, however Sentalloy and NIC showed small pores on the wire surface. The surface roughness was 0.09 μm for Highland, 0.25 μm for Sentalloy, 0.28 μm for Ormco and 0.46 μm for NIC archwire. The Highland was smoothest and NIC was the roughest. There were in significant (p < 0.05) difference of surface roughness of each brands. The results showed that the four manufactures NiTi archwires were different in grain size, wire surface and surface roughness. During clinical application, these archwires may exhibit different mechanical properties, such as strength, hardness, ductity, and friction because of their microstructure.

Microstructure of Semi-Solid Extruded Copper Alloy after Heat Treatment

2019 ◽  
Vol 285 ◽  
pp. 146-152
Author(s):  
Nai Yong Li ◽  
Han Xiao ◽  
Chi Xiong ◽  
De Hong Lu ◽  
Rong Feng Zhou
Keyword(s):  
Heat Treatment ◽  
Heat Treatment Temperature ◽  
Copper Alloy ◽  
Treatment Time ◽  
Solid Phase ◽  
Treatment Temperature ◽  
Primary Phase ◽  
Holding Time ◽  
Average Grain Size ◽  
Semi Solid

The semi-solid extruded ZCuSn10P1 copper alloy were annealed at different temperatures and time. The influences of heat treatment temperature and holding time on the microstructure of semi-solid ZCuSn10P1 copper alloy were investigated. The results show that with the increase of heat treatment temperature, the morphology of the semi-solid microstructure was improved, the sharp angle around the primary phase α-Cu and the liquid droplets were reduced. With the increase of heat treatment time, the solid-liquid segregation of the semi-solid structure was improved. The average grain size of the solid phase increased with the increasing of the holding time. After heat treatment, the solid solubility of the primary phase α-Cu increased, and the Sn and P elements in the liquid phase continued to diffuse to the primary phase α-Cu. The microstructure of semi-solid copper alloy was the most uniform after heat treatment at 350°C for 120 min.

scholarly journals Effect of Heat-Treatment on the Thermal and Mechanical Stability of Ni/Al2O3 Nanocrystalline Coatings

2020 ◽  
Vol 4 (1) ◽  
pp. 17
Author(s):  
Kavian O. Cooke ◽  
Tahir I. Khan ◽  
Muhammad Ali Shar
Keyword(s):  
Heat Treatment ◽  
Grain Size ◽  
Mechanical Stability ◽  
Chemical Properties ◽  
Treatment Temperature ◽  
Al2o3 Coating ◽  
Operational Temperature ◽  
Average Grain Size ◽  
Properties Of Materials ◽  
Physical And Chemical

Heat-treatment is a frequently used technique for modifying the physical and chemical properties of materials. In this study, the effect of heat-treatment on the mechanical properties, thermal stability and surface morphology of two types of electrodeposited coatings (pure-Ni and Ni/Al2O3) were investigated. The XRD analyses showed that the crystal structure of the as-deposited coating changes from slightly amorphous to crystalline as the heat-treatment temperature increases. The heat-treatment of both the pure-Ni and the Ni/Al2O3 coating caused an increase of the grain size within the coatings. However, the unreinforced Ni coating experienced a faster growth rate than the Ni/Al2O3 coating, which resulted in a larger average grain size. The temperature-driven changes to the microstructure of the coatings caused a reduction in the hardness and wear resistance of the coatings. The presence of nanoparticles within the Ni/Al2O3 coating can successfully extend the operational temperature range of the coating to 473 K by pinning grain boundaries.

Annealing Treatment for Superplastic Forming of Twin Roll Casted AZ31 Magnesium Sheet

2011 ◽  
Vol 239-242 ◽  
pp. 50-54 ◽  
Author(s):  
Guo Dong Shi ◽  
Jun Qiao
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Mechanical Test ◽  
Dynamic Balance ◽  
Annealing Treatment ◽  
Optical Microscope ◽  
Grain Structure ◽  
Average Grain Size ◽  
Az31 Sheet ◽  
Twin Roll

Annealing treatments at 200°C, 250 °C, 300°C, and 350°C were conducted on a twin-roll casted AZ31 sheet with an initial average grain size of 10.11 mm. Microstructure and mechanical behaviors were studied by optical microscope observation and tensile mechanical test. Expermeintal results show that grain size experienced three stage evolution during 180 min annealing at each temperature: recrystallization refinement, stabilization under dynamic balance of recrystallization and grain growth, and grain growth. The minimum average grain size of 5.96 μm was achieved after 120 min annealing at 200°C. The refined grain structure causes a decrease of ultimate tensile strength and an increase of elongation, and facilitates superplastic deformation of the material.

Preparation and Catalytic Performance of Ti(SO4)2/γ-Al2O3 Catalysts for Oligomerization of 1-Butene

2013 ◽  
Vol 634-638 ◽  
pp. 696-700
Author(s):  
Lin Jiu Xiao ◽  
Peng Li ◽  
Yong Gang Sheng
Keyword(s):  
Heat Treatment ◽  
Physicochemical Properties ◽  
Heat Treatment Temperature ◽  
Catalytic Performance ◽  
Treatment Temperature ◽  
Impregnation Method ◽  
X Ray Diffraction ◽  
Isothermal Adsorption ◽  
X Ray ◽  
Adsorption Desorption

A series of Ti(SO4)2/γ-Al2O3 catalysts were prepared by impregnation method and the catalytic performance of these catalysts in 1-butene oligomerization was investigated. The heat treatment temperature played great influences on the catalytic performance of these catalysts in the oligomerization. 90.1 wt.% conversion of 1-butene and 92.2 wt.% selectivity of dimers were obtained on Ti(SO4)2/γ-Al2O3(450) catalyst at 80 °C, 1.0 Mpa and LHSV=0.6 h−1. The heat treatment temperature determined the crystallinity of TiOSO4 and specific surface area of these catalysts, which affected the catalytic performance of these catalysts in 1-butene oligomerization. In addition, the physicochemical properties of these catalysts were comparatively characterized by powder X-ray diffraction (XRD), N2 isothermal adsorption-desorption techniques.

Phase Separation in Alumina-Chromia

2002 ◽  
Vol 731 ◽  
Author(s):  
M. S. McIntosh ◽  
T. H. Sanders ◽  
J. M. Hampikian
Keyword(s):  
Heat Treatment ◽  
Heat Treatment Temperature ◽  
Treatment Temperature ◽  
Miscibility Gap ◽  
Mole Percent ◽  
Tem Analysis ◽  
X Ray ◽  
Heat Treated ◽  
Solution Models ◽  
Liquid And Solid Phases

AbstractThe alumina-chromia system shows complete mutual solubility and is represented by an isomorphous phase diagram. However, the alumina-chromia system exhibits an asymmetric miscibility gap under 1300°C. Using existing data from the literature, the alumina-chromia system was assessed using thermodynamic modeling by Kim and Sanders [1]. Regular and subregular solution models for the liquid and solid phases were used to define the phase boundaries for the miscibility gap in this system. Using this thermodynamic representation of the miscibility gap to select temperatures of interest, 75 mole percent Al2O3samples were synthesized via combustion of powders, followed by pressing into pellets and heat-treated for various times and temperatures. Both X-ray and TEM analysis showed evidence of spinodal decomposition after heat-treatment. X-ray analysis showed that decreasing the heat-treatment temperature increases the compositional difference between the phases present. The experimentally observed microstructures exhibit lamella-like structures that vary in spacing from 8nm to 3nm as the heat-treatment temperature varies from 400°C to 800°C.

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