• Title/Summary/Keyword: press-die making

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Variation of microstructures and mechanical properties of hot heading process of super heat resisting alloy Inconel 718 (초내열 합금 Inconel 718 열간 헤딩 공정에서의 조직 및 기계적 특성 변화)

  • Choi, Hong-Seok;Ko, Dae-Chul;Kim, Byung-Min
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.1373-1378
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    • 2007
  • Metal forming ins the process changing shapes and mechanical properties of the workpiece without initial material reduction through plastic deformation. Above all, because of hot working carried out above recrystallization temperature can be generated large deformation with one blow, it can produce with forging complicated parts or heat resisting super alloy such as Inconel 718 has the worst forgeability. In this paper, we established optimal variation of hot heading precess of the Inconel 718 used in heat resisting component and evaluated mechanical properties hot worked produce. Die material is SKD61 and initial temperature is $300^{\circ}C$. Initial billet temperature and punch velocity changed, relatively. Friction coefficient is 0.3 as lubricated condition of hot working. CAE is carried out suing DEFORM software before making the tryout part, and it is manufactured 150 ton screw press with optimal condition. It is known that forming load was decreased according to decreasing punch velocity.

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Evaluation of incremental sheet forming characteristics for 3D-structured aluminum sheet - part 2 (3D 구조 알루미늄 판재의 점진판재성형 특성 평가 (제2보))

  • Kim, Young-Suk;Do, Van-Cuong;Ahn, Dae-Chul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.3
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    • pp.1585-1593
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    • 2015
  • 3D-structured (embossed) aluminum sheets have been used in the heat insulation purpose for automative exhaust parts because of increasing their surface areas and stiffness reinforcement imposed in making the embossing pattern. However, there are many restrictions in press forming of the embossed sheet compared with the flat sheet (non-embossed one) because of its difference in the mechanical properties and the geometrical 3-dimensional shape. In this paper we investigated the deformation characteristic of embossed aluminum sheet in the incremental sheet forming process which has frequently used in the design verification and the trial manufacturing of sheet products. The single point incremental forming (SPIF) experiments for the rectangular cone forming using the CNC machine with a chemical wood-machined die and a circular tool shape showed that the formability of the embossed sheet are better than that of the flat sheet in view of the maximum angle of cone forming. This comes from the fact that the embossed sheet between the tool and the elastic die wall is plastically compressed and the flatted area contributes to increase the plastic deformation. Also the tool path along the outward movement from the center showed a better formability than that of the inward movement from the edge. However the surface quality for the tool path along the outward movement evaluated from the surface deflection is inferior than that of the tool path along the inward movement.

A Study on Human Rights in North Korea in terms of Haewon-sangsaeng (해원상생 관점에서의 북한인권문제 고찰)

  • Kim Young-jin
    • Journal of the Daesoon Academy of Sciences
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    • v.43
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    • pp.67-102
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    • 2022
  • The purpose of this study is to analyze the human rights found in the North Korean Constitution and their core problem by focusing on elements of human rights suggested by Daesoon Jinrihoe's doctrine of Haewon-sangsaeng (解冤相生 the Resolution of Grievances for Mutual Beneficence). Haewon-sangsaeng is seemingly the only natural law that could resolve human resentment lingering from the Mutual Contention of the Former World while leading humans work for the betterment of one another. Haewon-sangsaeng, as a natural law, includes the right to life, the right to autonomous decision-making, and duty to act according to human dignity (physical freedom, the freedom of conscience, freedom of religion, freedom of speech, freedom of press, etc.), the right to equal treatment in one's social environment, and the right to ensure the highest level of health through treatment. The North Korean Constitution does not have a character as an institutional device to guarantee natural human rights, the fundamental principle of the Constitution, and stipulates the right of revolutionary warriors to defend dictators and dictatorships. The right to life is specified so that an individual's life belongs to the life of the group according to their socio-political theory of life. Rights to freedom are stipulated to prioritize group interests over individual interests in accordance with the principle of collectivism. The right to equality and the right to health justify discrimination through class discrimination. The right to life provided to North Koreans is not guaranteed due to the death penalty system found within the North Korean Criminal Code and the Criminal Code Supplementary Provisions. The North Korean regime deprives North Koreans of their right to die with dignity through public executions. The North Korean regime places due process under the direction of the Korea Worker's Party, recognizes religion as superstition or opium, and the Korea Worker's Party acknowledge the freedoms of bodily autonomy, religion, media, or press. North Koreans are classified according to their status, and their rights to equality are not guaranteed because they are forced to live a pre-modern lifestyle according to the patriarchal order. In addition, health rights are not guaranteed due biased availability selection and accessibility in the medical field as well as the frequent shortages of free treatments.