The Experts below are selected from a list of 38373 Experts worldwide ranked by ideXlab platform
Bojan Težak - One of the best experts on this subject based on the ideXlab platform.
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A simulation of heat transfer during Billet transport
Applied Thermal Engineering, 2002Co-Authors: Anton Jaklič, Branislav Glogovac, Tomaž Kolenko, Borut Zupančič, Bojan TežakAbstract:This paper presents a simulation model for Billet cooling during the Billet's transport from the reheating furnace to the rolling mill. During the transport, the Billet is exposed to radiation, convection and conduction. Due to the rectangular shape of the Billet, the three-dimensional finite-difference model could be applied to calculate the heat conduction inside the Billet. The Billets are reheated in a gas-fired walking-beam furnace and are exposed to scaling. The model takes into account the effect of the thin oxide scale. We proved that the scale significantly affects the temperature distribution in the Billet and should not be neglected. The model was verified by using a thermal camera.
Anton Jaklič - One of the best experts on this subject based on the ideXlab platform.
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A simulation of heat transfer during Billet transport
Applied Thermal Engineering, 2002Co-Authors: Anton Jaklič, Branislav Glogovac, Tomaž Kolenko, Borut Zupančič, Bojan TežakAbstract:This paper presents a simulation model for Billet cooling during the Billet's transport from the reheating furnace to the rolling mill. During the transport, the Billet is exposed to radiation, convection and conduction. Due to the rectangular shape of the Billet, the three-dimensional finite-difference model could be applied to calculate the heat conduction inside the Billet. The Billets are reheated in a gas-fired walking-beam furnace and are exposed to scaling. The model takes into account the effect of the thin oxide scale. We proved that the scale significantly affects the temperature distribution in the Billet and should not be neglected. The model was verified by using a thermal camera.
Jeong-rock Kwon - One of the best experts on this subject based on the ideXlab platform.
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Ultrasonic transducers for continuous-cast Billets
Sensors and Actuators A: Physical, 1995Co-Authors: Byoung-chul Shin, Jeong-rock KwonAbstract:Abstract In order to detect internal defects larger than 20 mm in continuous-cast steel Billets, our team investigated the frequency and beam width of ultrasonic transducers. Internal defects larger than 20 mm cannot be detected by measuring defect echoes because large defects absorb ultrasonic wave energy. So, large defects should be detected by means of the energy loss. The energy loss is related to the intensity of the back echo. If a steel Billet has large defects, it absorbs ultrasonic wave energy and the intensity of the back echo decreases. This means that the energy loss is available for detecting the large defects. Therefore, in order to detect a large defect by back echo, the back echo through a defect-free Billet should be of greater intensity than a set value. Because the average density of continuous-cast steel Billets is lower than that of hot-rolled Billets, the back echoes through the cast Billets are weaker than those through the rolled ones. For detecting large flaws in cast Billets, the back echoes through defect-free zones should be higher than a set level, such as 50 dB in our system. Our team changed the center frequencies of the transducers from 1 to 4 MHz by changing the thickness of the piezoelectric ceramic plates. 2.25 MHz transducers having 9 mm wide piezoelectric ceramics show the best characteristics for detecting large defects (20 mm) in continuous-cast steel Billets.
Carl M. Lombard - One of the best experts on this subject based on the ideXlab platform.
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Effect of core insulation on the quality of the extrudate in canned extrusions of γ-titanium aluminide
Journal of Materials Processing Technology, 1992Co-Authors: R. L. Goetz, Vinod K. Jain, Carl M. LombardAbstract:Abstract Non-isothermal forward extrusions of cast γ-TiAl (Ti-49.5Al-2.5Nb-1.1Mn, at%) were performed with Billet temperatures of 1050, 1150, and 1225°C and a die and container temperature of 260°C. The Billets were canned using 304 stainless steel tubing. Finite-element analysis indicates that rapid heat loss occurs from the canned Billet to the die during the extrusion process. The temperature gradient in the Billet produces non-uniform microstructure. A technique was developed to insulate the Billet with layers of 0.050 inch (1.27 mm) thick silica fabric. The use of an insulator reduces Billet heat loss during its transfer from furnace to press and during the extrusion process. Differences in microstructure and mechanical properties of the extrusions performed with and without the silica insulation were investigated and compared.
Tomaž Kolenko - One of the best experts on this subject based on the ideXlab platform.
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A simulation of heat transfer during Billet transport
Applied Thermal Engineering, 2002Co-Authors: Anton Jaklič, Branislav Glogovac, Tomaž Kolenko, Borut Zupančič, Bojan TežakAbstract:This paper presents a simulation model for Billet cooling during the Billet's transport from the reheating furnace to the rolling mill. During the transport, the Billet is exposed to radiation, convection and conduction. Due to the rectangular shape of the Billet, the three-dimensional finite-difference model could be applied to calculate the heat conduction inside the Billet. The Billets are reheated in a gas-fired walking-beam furnace and are exposed to scaling. The model takes into account the effect of the thin oxide scale. We proved that the scale significantly affects the temperature distribution in the Billet and should not be neglected. The model was verified by using a thermal camera.