• 보존과학회지
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• 제37권1호
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• pp.34-42
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• 2021

This study analyzes six slags excavated from the iron making site in Gogi-ri, Namwon, Korea to understand the characteristics of the ruins, and to confirm the iron making process performed at the time. The chemical components of the iron making by-products from the Gogi-ri site were analyzed, and the findings indicate total Fe contents between 23.24% and 37.56%, which are lower than the typical total Fe content found in ancient iron making processes. The deoxidation agent contents of the slags ranged from 43.88% to 58.13%, which are higher than the typical deoxidation agent content of ancient iron making processes. The high content suggests smooth separation between iron and slags, and TiO₂ detected from the site suggests the use of materials with high titanium content in the iron making in the region. As for the microstructures of the slags, some slags have long pillar-shaped fayalites, while others have pillar-shaped wüstite along with ulvöspinel. Slags from the forging furnace show hammer scales created by both the earlier stages and later stages of forging work. The findings suggest that the iron making site in Gogi-ri, Namwon, Korea used to be an iron making facility where a full range of iron making process was carried out ranging from smelting to forging, and the ironmakers used a wide array of technologies to manufacture iron products.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 추계학술대회 논문집
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• pp.197-198
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• 2008

The forging process produces complicated and designed components in a die at high productivity for mass production and minimizes the machining amount for favorable material utilization; the forging products used at highly stressed sections are well accepted at a wide range of industry such as automobile, aerospace, electric appliance and et cetera. Accordingly, recent R&D activities have been emphasized on improvement of forging die-life and near net shaping technology for cost effectiveness and better performance. Usually closing and consolidation of internal void defects in a ingot is a vital matter when utilized as large forged products. It is important to develop cogging process for improvement of internal soundness without a void defect and cost reduction by solid forging alone with limited press capacity. For experiments of cogging process, hydraulic press with a capacity of 800 ton was used together with a small manipulator which was made for rotation and overlapping of a billet. Size of a void was categorized into two types; ${\phi}$ 6.0 mm and ${\phi}$ 9.0 mm to investigate the change of closing and consolidation of void defects existed in the large ingot during the cogging process. In addition for forming experiment of piston grown air drop hammer with a capacity of 16 ton was used. The experiment with piston crown was carried out to show the formability and void closing status. In this paper systematic configuration for closing process of void defects were expressed based on this experiment results in the cogging process. Also forging defects through forming process for piston crown was improved using the experiment results and FE analysis. Consequently this paper deals with the effect of radial parameters in cogging process on a void closure far large forged products and formability of piston crown.

• 한국기계가공학회지
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• 제18권6호
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• pp.106-112
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• 2019

Rotary swaging is a method of forging automotive drive shafts. In this paper, we propose a new two-hammer forging technique by applying the problem-solving approach TRIZ to improve the efficiency and productivity of the rotary swaging automation process. We will simplify the materials and hammers via the 3D modeling tool SolidWorks for high accuracy of a comparative analysis of existing and proposed methods under the same boundary conditions. In addition, we will compare the stress trends of the proposed model using ANSYS Workbench and verify the feasibility through a comparison of the simulation results using DEFORM. Relative to the existing method, the proposed method can decrease production costs and improve efficiency of the automation process by reducing the power source.