• Title/Summary/Keyword: carburizing

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Metallurgical Study of Iron Artifacts Yangju-Mountain Fortress (양주 대모산성 출토 철기유물의 금속학적 연구)

  • Lim, Sun-Ki;Kang, Dai-Ill;Moon, Whan-Suk;Park, Dong-Kyu;Kang, Sung-Goon
    • 보존과학연구
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    • s.14
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    • pp.1-34
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    • 1993
  • 1. Metallurgical Properties of Iron artifacts excavated from Yangju-Mountain fortress were studied for the scientific conservation and metallurgical history of ancient Iron artifacts.2. Iron artifacts form Yangju-Mountain fortress were found to be the products of having well-established Carburizing and remelting technique in that period.3. These artifacts seem to be manufactured from very pure ores, because very pure ferrite structure and low impurity.4. Especially evidence of very suitable carburizing technic well-established and usealloying method of Fe-C system on purpose were found.5. Cast iron artifacts were found to be eutectic composition (4.31%) having lowestmelting point in Fe-C system.

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Strength Change in Ultra Low Carbon Steel due to Carburizing Heat Treatment for Hot Press Forming (HPF 적용을 위한 극저탄소강의 강도에 미치는 침탄 열처리의 영향)

  • Kang, Soo Young
    • Korean Journal of Metals and Materials
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    • v.50 no.6
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    • pp.433-438
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    • 2012
  • Strength change in ultra low carbon steel carburized at $880^{\circ}C$ and $930^{\circ}C$ for 10, 30, 60 and 120 minutes was investigated. The results were analyzed by a tensile test, chemical composition analysis, optical microscopy and scanning electron microscopy. Stress in the 0.5% strain specimen in the tensile test increased as the time treated at $880^{\circ}C$ and $930^{\circ}C$ increased, because the carbon diffusion layer and the martensite of the specimen increased with increasing treatment time. Martensite was found in the ferrite region in the specimen treated at $880^{\circ}C$, which is attributed to grain boundary diffusion.

A Statistical Study on the Fatigue Behaviors of Nitro-Carburized SCM415 (침탄질화 처리된 SCM415재의 피로거동에 대한 통계적 연구)

  • Song, Sam-Hong;Lee, Sang-Hoon;Lim, Se-Hyuck
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.5
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    • pp.128-133
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    • 1997
  • Due to their high strength and good wear resistance, nitro-carburizing materials have been used for many machine components. However, the nitro-carburizing materials are found to have one disadvantage ; that is, their strength and fatigue life show larger scatter than those of non-heated metals. In this paper, therfore, the statistical chracteristics of non-heated and nitro-carburized specimens for SCM415 are investi- gated under two different of stress levels 1.15 .sigma. /sub .omega. / .leq. / .sigma. / sub .alpha. / .leq. / 1.25 .sigma. /sub .omega. /. Seven specimens at each stress level are tested by using rotating bending fatigue tester. The relation between a crack length and fatigue cycles can be arranged for Weibull distribution, and S-N curve using 95% reliability function is obtalined for nitro-carburized specimen.

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