• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.248-251
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• 2009

AB100 & CB100 are general products in the steel beam of the section shape. They are applied for construction, welding and shipbuilding structures. But currently roll damages are generated in the intermediate & finish mills during producing AB 100, CB100. The goal of this project is to conduct rolling & roll stress analysis using the 3D FEM program and to research the things which roll diameter affects roll stress. By the analysis results, it is determined that the recording roll stress where the roll diameter will be big comes to be small, and it is recognized that roll damage occurrences of finish rolling mills can be high by roll stress analysis results.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.4
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• pp.146-150
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• 2015

Steel is produced through the steel-making process with a desired shape by a rolling press. Scrap is removed according to the sheet edge to improve the quality of the product. This machine is called a side trimmer. This study aimed to develop a side trimmer for automatically changing the width of the trimming knife without line stopping. This machine consists of a housing opening device and a turning device. The measuring technologies of sheet width, trimming knife rotation angle, and knife gap for increasing the control accuracy. This experiment was conducted to evaluate the performance of the developed technologies. It was reduced by 10% compared with the operation time of the conventional method.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.5
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• pp.82-86
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• 2013

The automotive weather strip has the functions isolating of dust, water, noise and vibration from outside. The core of weather strip is made of steel with stiffness. By using the wire formed as the core of weather strip, weight can be reduced as much as 35% by comparing with existing steel core. For this reason, forming wire is necessary to keep the zigzag shape as it is. The deformation which is occurred during forming process can be predicted and it can be used in case of manufacturing dies through CAE. In this paper, rolling process conditions are deduced and the springback amount is predicted after rolling process by using the simulation. The springback amount of product is measured by using optical microscope, and measurement result is compared with the simulation result of springback as the same condition. The suitable gap between dies to compensate springback after rolling process is predicted through simulation and it is used for manufacturing dies.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.180-180
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• 2000

The shape of cold strip for the stainless process has been become issue in quality recently, and hence POSCO (Pohang Iron & Steel Co., Ltd) developed an automatic control system for strip shape in the sendzimir mill. The strip shape is measured by an outward measuring roll and is controlled by As_U roll and first intermediate roll. As_U roll consists of 8 saddles, which are controlled vertically. The fist intermediate rolls, which are controlled horizontally, consist of two pairs of rolls up and down. A developed shape control system is applied to real plant by using fuzzy logic and neural network method to control actuators; As_U roll and first intermediate roll. This system composes mainly of three parts as a real-time system, input to output conditioner board, and man-machine interface. The actual shape is recognized by neural network and converted into symmetric shape. The fuzzy controller, based on the shape from neural network and sensor, controls positions of the As_U roll and first intermediate roll. This paper verifies the shape controller performance. The experiments are made on line for the sendzimir mill. The shape control performance shows very efficient for the target tracking, shape symmetry, and fluctuation of shape.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.10a
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• pp.425-428
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• 2009

Aerospace engine application needs to stand high temperature and pressure. Because of its mechanical properties such as high strength at high temperature, Alloy 718 is used aerospace engine application about 80%. But alloy 718's mechanical properties cause some problem to manufacturing profile ring like damage of material and mold. In this study, alloy 718's mechanical properties investigated for knowing its formability and using FE-Simulation for designing profile ring roll process and mold shape. Profile ring rolling processing is designed with "Initial material$\rightarrow$Blank$\rightarrow$Linear Ring$\rightarrow$Profilering". Blank's heating temperature is setting $1100^{\circ}C$ for manufacturing a trial profile ring on the basis of FE-Simulation. As a result of manufacturing alloy 718 profile ring, it is possible to make near target profile shape ring with all of the processing condition which gives in this study.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.1
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• pp.58-61
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• 2003

Moisture content was 79.5%, banjhi shoot was 77.8% of the total and the weight was 29.4 g/100 buds in the harvested plant leaves used for manufacturing Okro tea. Okro tea heated at 75$^{\circ}C$ for 30 min showed the best quality among all the treatmants. Chemical components such as total nitrogen, theanine, arginine and chlorophyll were high in the tea treated at 75$^{\circ}C$ for 30 min compare with those of other treatments. The sensory evalution test In terms of appearance shape color and taste showed greater preferences in Okro tea treated at 75$^{\circ}C$ for 30 min than those of other treatments. The results suggested that heat treatment at 75$^{\circ}C$ for 30 min was the best condition for the final rolling process in manufacturing of Okro tea.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.08a
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• pp.308-312
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• 1999

Developed the model equations which calculate roll force, roll power during hot rolling in real time. The variables which mainly effect on the roll force, roll power are shape factor, reduction, roll diameter, roll velocity, strip inlet temperature, carbon content of strip and strip-roll contact friction coefficient. Among these variables roll diameter, roll velocity, inlet temperature, carbon content and friction coefficient can be excluded in interpolated model equation by introducing equation of die force(F'), power(p') of the frictionless uniform plane strain compression which can be calculated without iteration. At the case of coulomb friction coefficient of 0.3, we evaluated coefficient of polynomial equations of {{{{ { F} over {F' } }}}}, {{{{ { Pf} over {Pd }, { Pd} over {P' } }}}} from the result of finite element analysis using interpolation. It was found that the change of values of {{{{ { F} over {F' }, { P} over {P' } }}}} with the friction coefficient tend to straight line which slope depend only on shape factor. With these properties, developed model equations could be extended to other values of coulomb friction coefficient. To verify developed roll force, roll power model equation we compared the results from these model equation with the results from these model equation with the results from finite element analysis in factory process condition.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.426-429
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• 2005

In this study, the formed tool is used to machine of bearing raceway and a shape compensation scheme is proposed to compensate for shape of it in turning process. It is introduced the conventional design method of the formed tool; a simple depth compensation method and a drawing compensation method. And it is performed to investigate in detail properties of the formed tool about a tool angle and problems of a turning process of bearing raceway using the formed tool. The applicability of the proposed scheme is examined by comparing the experimental results obtained by a new designed formed tool with those obtained by a conventional tool.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.437-438
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• 2006

Generally, the vertical roll process is used to achieve extensive width reduction in hot strip mill. However, it is difficult to avoid the defects such as dog-bone and seam-defect. The sizing press has been developed in response to the defects mentioned above. Especially, this study is carried out to investigate the deformation of slab by two-step sizing press. The deformation behavior in the width sizing process is more favorable than that in conventional vertical rolling edger. The objective of this study is to determine the optimal anvil shape parameters in the sizing press with two-step die from the viewpoint of edge-seam length. In general, the edge-seam defect occurs parallel to the rolling direction at both edges in horizontal rolling process after sizing press. The optimal combination of the parameters is determined by FE-simulation and Artificial Neural Network (ANN). The slab deformation in sizing press with convex anvil is analyzed by FE-simulation. The most suitable profile of the anvil is also discussed fur the improvement of trimming loss because of the side seam defect by FE-simulation and ANN.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.417-420
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• 2009

The hot forming process of a CAM for vessel engine was designed by finite element (FE) simulation and experimental analysis. An aim of process design was to achieve the near-net shaped CAM forgings by hot forging process. Based on the compression test results of the low alloy steel, deformation processing map was generated using the superposition approach between the dynamic materials model (DMM) and flow stability and/or instability criteria. From the processing map, the initial heating temperature was determined as $1200^{\circ}C$. FE analysis was simulated to predict the formation of rolling defects and deformed shape with different forging designs. Optimum process design suggested in this work was made by comparing with the CAM for vessel engine manufactured by actual forging process.