• Proceedings of the KWS Conference
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• 2005.06a
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• pp.294-296
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• 2005

Several duplex overlaied-weldments which have different ferrite ratio were prepared by changing welding heat input ant post weld heat treatment were carried out to understand the effect of the ferrite ratio on the precipitation during post weld heat treatment. High heat input weldment indicated low ferrite ratio, while low heat input weldment has high ferrite ratio. Low ferrite ratio weldment showed much and faster precipitation. But high ferrite ratio weldment showed less and slower precipitation.

• Journal of the Korean Society for Heat Treatment
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• v.8 no.1
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• pp.75-83
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• 1995

The purpose of this study is to investigate the effect of heat treatments on the martensite transformation and tensile deformation behavior in Ti-Ni-B alloys with various boron concentration. Three types of heat treatment are given to the specimens; i) solution treatment ii) aging iii) thermo-mechanical treatment. In solution treated specimens. R-phase transition which is related to abnormal increase of electrical resistance prior to martensitic transformation has been formed at a boron content of 0.2at % and the $M_s$ temperature has been decreased with the increasing of boron content. However. It has not been affected by aging, while that of thermo-mechanically treated specimens has been remarkably increased in the vicinity of recrystallization temperature. The thermo-mechanically treated specimen has showed a good thermal fatigue characteristics, shape memory effect and superelasticity in comparison with the solution treated specimen.

• Journal of Dairy Science and Biotechnology
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• v.35 no.1
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• pp.55-72
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• 2017

The second article of 'Effects of heat treatment on the nutritional quality of milk,' titled 'Destruction of microorganisms in milk by heat treatment' and authored by Dr. Seong Kwan Cha, who worked at the Korea Food Research Institute, covers the heat-stable microorganisms that exist in milk after pasteurization. The article focusses on the microbiological quality of raw milk and market milk following heat treatment, and is divided into four sub-topics: microbiological quality of raw milk, survey and measurement of microorganisms killed in raw milk, effect on psychrophilic and mesophilic microorganisms, and effect of heat treatment methods on thermoduric microorganisms. Bacillus spp. and Clostridium spp. are sporeforming gram-positive organisms commonly found in soil, vegetables, grains, and raw and pasteurized milk that can survive most food processing methods. Since spores cannot be inactivated by LTLT (low temperature long time) or HTST (high temperature short time) milk pasteurization methods, they are often responsible for food poisoning. However, UHT (ultra high temperature) processing completely kills the spores in raw milk by heating it to temperatures above $130^{\circ}C$ for a few seconds, and thus, the UHT method is popularly used for milk processing worldwide.

• Carbon letters
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• v.8 no.2
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• pp.127-133
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• 2007

In this study, commercially available pitch-based carbon fibers of general grade were post-heat-treated using a boxtype high temperature furnace at $1800^{\circ}C$, $2000^{\circ}$, $2200^{\circ}C$, and $2400^{\circ}C$, respectively. The fundamental characteristics of each heat-treated carbon fibers were investigated in terms of chemical composition, morphology, thermal stability, X-ray diffraction, single filament tensile test, and electrical resistivity. The result showed that the fiber properties were significantly influenced by the post-heat-treatment, indicating the greater effect with increasing treatment temperature. The carbon contents, thermal stability, and tensile properties of the carbon fibers used here were further increased by the post-heat-treatment, whereas the d-spacing between graphene layers and the electrical resistivity were reduced with increasing post-heat-treatment temperature.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.391-394
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• 1998

The effect of the heat treatment of the AZO transparent conductive film prepared by rf magnetron sputtering was investigated. The variations of the electrical and optical properties with heat treatment ambient and temperature were studied. After the heat treatment in air above 300.deg. C, the resistivity of AZO films increased by 1 to 8 orders of magnitude. However, no significant change in the AZO films after th eheat treatment in vacuum was not observed.

• Journal of Korea Foundry Society
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• v.9 no.6
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• pp.463-473
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• 1989

This study is aimed to investigate the effect of cyclic heat treatment which is special heat treatment on the strength and toughness in Multi-phase(Ferrite-Bainite-Martensite) Ductile cast Irons. Spceimens were austenitized at eutectoid transformation temperature range(${\alpha}+{\gamma}$) for 30min and austempered at $300^{\circ}C$ and $400^{\circ}C$ for different holding times, and then quenched in ice water to obtain the multi-phase(Ferrite-Bainite-Martensite) structure from various prior structures, which was obtained by various cyclic heat treatments. As the number of cycle in cyclic heat treatment increased, volume fraction of pearlite increased and the its morphology was refined. As the number of cycle in cyclic heat treatment increased, the multi-phase(Ferrite-Bainite-Martensite) was dispersed in whole matrix as refined island phase. Particularly, martensite among the multi-phase gradually became a spherical shape. Good combination in impact energy and tensile strength was detained in $840^{\circ}C-300^{\circ}C-15min$ condition after 10 cycles in cyclic heat treatment, and its multi-phase volume fraction is Ferrite(50%)-Martensite(l3%)-Bainite(37%).

• International Journal of Precision Engineering and Manufacturing-Green Technology
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• v.9
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• pp.485-492
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• 2021

The athermal effect of electric current during electrically assisted (EA) annealing, which is a simple and cost-effective heat treatment technique, is assessed by comparing the performances of EA annealing and induction heat treatment (IHT), using aluminum alloy specimens with a high dislocation density from cold rolling. The dislocation densities after EA annealing and IHT are calculated using X-ray diffraction data to compare the performance of the processes. The performance of EA annealing clearly surpasses that of IHT in a certain temperature range. However, at higher temperatures, the thermal effect alone is able to induce nearly complete annihilation of dislocation density, thus, the practical advantage of EA annealing may diminish.

• Journal of the Korean Wood Science and Technology
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• v.36 no.2
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• pp.1-8
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• 2008

This study was performed to evaluate the burning characteristics of wood-based materials and the effect of surface treatment of fire retardant using cone calorimeter. Four types of wood-based materials, such as Plywood, Oriented Strand Board (OSB), Particle Board (PB) and Medium Density Fiberboard (MDF), were tested at a constant heat flux of $50kW/m^2$ to investigate the time to ignition, mass loss rate, heat release rate, effective heat of combustion, etc. In addition, each type of wood-based material was tested at the same heat flux after fire retardant treatment on the surface to evaluate the effect of this treatment on the burning characteristics. The surface treatment of fire retardant, by the amount of $110g/m^2$, delayed the time to ignition almost twice. However, it was indicated that heat release rate, mass loss rate, and effective heat of combustion were not significantly affected by fire retardants treatment for all types of wood-based materials.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.4
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• pp.539-544
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• 2009

The constraint effect $A_2$ has to be evaluated within plastic region near crack tip front using opening displacement. Plastic boundary and stress or strain conditions in the vicinity of the crack tip using recrystallization heat treatment was represented. It was found that the plastic deformation boundary by recrystallization heat treatment method was the true strain of ${\epsilon}t$ = 0.05mm/mm. With the estimation of constraint effects $A_2$, the region of proper displacement measurement point near crack tip was between 0mm and 1mm distance toward direction of crack propagation, and was between 1mm to 3mm distance toward direction of load line.

• Journal of the Korean Society for Heat Treatment
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• v.17 no.6
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• pp.342-345
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• 2004

In this work, a new method of measuring volume fraction of deformation-induced ${\varepsilon}$ martensite is proposed using endothermic heat on reverse transformation. As grain size increases, the amount of ${\varepsilon}$ martensite forming on cooling increases. However, with a decrease in grain size, more ${\varepsilon}$ is induced by deformation, improving shape memory effect.