• 제목/요약/키워드: 중탄

검색결과 66건 처리시간 0.032초

자동차 엔진 캡 소재의 절삭 특성에 관한 연구 (A Study on the Machining Characteristics of Engine Cap Meterials for a Automobile)

  • 채왕석;김동현
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1995년도 추계학술대회 논문집
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    • pp.185-188
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    • 1995
  • In this paper, We have analyzed dynamic characteristics of cutting force. Test materials are used in the tempered carbon steek and non-tempered carbon steel. The obtained results ase as follows: 1. Cutting force is smaller non-tempered carbon steel than tempered carbon steel when feed speed make a change. 2. Specific cutting force is smaller non-tempered carbon steel than tempered caron steel when cutting depth make a change

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무기(無機) 충진재(充鎭材) 첨가(添加)에 따른 재생(再生) 폐(廢)비닐의 특성(特性) 분석(分析) (I) - 중탄과 칼펫의 첨가(添加)에 따른 영향(影響) - (A Study on the Behaviors of Inorganic Fillers in Recycling of the Waste Agricultural Plastic Films (I) - Effects on the Addition of Calcium Carbonate and Calpet -)

  • 안태광;손상진;김혜태;김명호;주공명;진덕진
    • 자원리싸이클링
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    • 제17권3호
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    • pp.10-20
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    • 2008
  • 농업용 폐비닐의 재활용에 대한 무기충진재의 거동을 연구하기 위하여 한국환경자원공사 시화 및 정읍공장에서 세척된 PE fluff들을 각각 사용하였다. 먼저 PE 플러프에 무기충진재인 탄산칼슘과 칼펫을 배합비율별로 혼합하여 용융 압출을 통한 시험용 펠렛들을 제조한 후 프레스 몰딩을 거쳐 시료별로 시험용 시트들을 제작하였다. 이들 무기충진 복합재의 기계적 특성인 인장, 굴곡, Izod 충격시험을 실시하였고, 열적 특성인 열변형온도, vicat 연화온도, 용융흐름지수(MFI)를 시험 및 분석을 하였다. 또한 플라스틱 내부에서 무기충진재의 분산성 및 wetting정도를 확인하기 위하여 SEM을 통해 모폴로지를 조사하였다. 이들 결과로부터 물리적인 측면과 경제적인 관점에서 재생 PE와 무기충진재의 최적 배합비들을 얻었다.

자동차 차축 소재의 금속적 특징 및 밀링 절삭 특성 연구 (A Study on the Metrial Charcterisitics of Material Quality and Milling of Axle Materials for a Automobile)

  • 채왕석
    • 한국생산제조학회지
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    • 제6권1호
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    • pp.77-83
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    • 1997
  • In this paper, we have studied internal quality including chemical compositions, microscopic structure and nonmetalic inclusion of test materials. We have analyzed dynamic characteristics of cutting force of milling including tensile strength value, hardness etc. Test materials are used in the tempered carbon steel and the non-tempered carbon steel. The obtained results are as follows: 1. In analyzing internal quality, the tempered carbon steel have typical martensite structure and the non-tempered carbon steel have ferrite + pearlite structure. 2. Yield strength, tensile strength and hardness value are in the non-tempered carbon steel but elongation is maximum value in the tempered carbon steel. 3. Cutting force is smaller non-tempered carbon steel than tempered carbon steel when feed speed and depth on cut is constant. 4. Cutting force is smaller non-tempered carbon steel than tempered carbon steel when cutting speed and depth of cut is constant.

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중탄소강에서 합금원소 및 초석 페라이트가 기계적성질에 미치는 영향 (Effects of Alloying Elements and Pro-eutectoid Ferrite on Mechanicl Properties in Medium Carbon Steels)

  • 심혜정;송형락;남원종
    • 소성∙가공
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    • 제13권4호
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    • pp.350-358
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    • 2004
  • The effects of alloying elements on microstructural features and mechanical properties in 0.55%C medium carbon steels were investigated. The samples were austenitized at 105$0^{\circ}C$ for 30min. followed by quenching in a salt bath in the temperature range of 500 ~ $620^{\circ}C$. The addition of Cr resulted in the decrease of the volume fraction of pro-eutectoid ferrite and interlamellar spacing in pearlite and the increase of strength. However, the addition of B caused the increase of the volume fraction of pro-eutectoid ferrite. Reduction of area and Charpy impact values were influenced by the combined effect of microstructural features, such as the volume fraction of pro-eutectoid ferrite, interlamellar spacing and the thickness of lamellar cementite in pearlite.

중탄소강(中炭素鋼)의 파속인성치(破續靭性値)에 관(關)한 실험적(實驗的) 연구(硏究) (An Experimental Study on the Fracture Toughness of Middle Carbon Steel)

  • 심관식
    • 산업기술연구
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    • 제2권
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    • pp.69-75
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    • 1982
  • The fracture of a hot rolled SM 45C steel plate was investigated for various crack ratio, thickness and loading point using the method of J-integral. It was found that the stable crack growth increased as the thickness and crack ratio of the specimen. The results are summerized as follows. 1. The more crack ratio increase, the less fracture toughness tend to. 2. Considering fracture toughness, a thin specimen is stronger a thick one. 3. Considering only the bending of specimen without thickings of the axial direction, we can get $J_{1c}$ value decreased about 10 percentage within the scope of experimental crack ratio.

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레이저 표면경화처리에서 빔의 형태가 경화층 크기에 미치는 영향에 관한 연구 (A Study on the Effect of Beam Mode on the Size of Hardened Zone in Laser Surface Hardening)

  • Kim, J.W.
    • 한국정밀공학회지
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    • 제10권4호
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    • pp.64-72
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    • 1993
  • Analytical models for the prediction of the size of hardened zone in laser surface hardening are presented. The models are based on the solutions to the problem of three-dimensional heat flow in plates with infinite thickness. The validity of the model was tested on medium carbon steel for Gaussian mode of beam. Then the model for rectagular beam was used for the predicition of the size of hardened zone on various hardening process parameters. From the calculation results it appeared that the size and shape of the hardened zone are strongly dependent on process parameters such as beam mode, beam size, and traverse speed.

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승용차용 CYLINDER ROD 소재의 밀링 적삭 특성 연구 (A Study on the Machining Charcterisitics of Milling of cylinderical Rod Materials for Passenger Car)

  • 채왕석
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 1996년도 춘계학술대회 논문집
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    • pp.143-148
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    • 1996
  • In this paper, we have studied internal quality including chemical compositions, microscopic structure and nonmetalic inclusion of test materials. We have analyzed dynamic characteristics of cutting force of milling including tensile strength value hardness etcs. Test materials are used the tempered carbon steel and the non-tempered carbon steel. The obtained results are as follows: 1.In analyzing internal quality, the tempered carbon steel have typical martensite structure and the non-tempered carbon steel have ferrite+pearlite structure. 2.Yield strength, tensile strength and hardness value are in the non-tempered carbon steel but elongation is maximum value in the tempered carbon steel. 3.Cutting force is smaller non-tempered carbon steel than tempered carbon steel when feed speed and depth of cut is constant. 4.Cutting force is smaller to the tempered carbon steel and smaller non-tempered carbon steel than tempered carbon steel when cutting conditions

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염소 가스 중독에서 나트륨 중탄산염의 흡입치료 2례 (Two Cases of Sodium Bicarbonate Inhalation Therapy in Chlorine Gas Intoxication)

  • 이동훈;어은경
    • 대한임상독성학회지
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    • 제2권1호
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    • pp.49-53
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    • 2004
  • A chlorine gas is a common irritant and when exposed, it result in mild occular, oropharyngeal, or respiratory symptoms. In severe case, however, it may result in pulmonary edema, interstitial pneumonia, or respiratory failure. We report the case of 29-year-old and 46-year-old men is accidentally exposed to chlorine gas during cleaning water. The patients complained dyspnea, chest tightness, cough and both eye pain. During hospitalization, they were treated with inhalation of humidified oxygen, beta-adrenergic agonist and $2\%$ sodium bicarbonate. After several days, patients were discharged without respiratory symptoms and complication. In treatment of chlorine gas toxicity the inhalation of sodium bicarbonate is a possible initial therapy can improve respiratory symptoms in spite of lack of evidence.

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S45C 기계구조용 중탄소강의 Nd:YAG Laser용접성에 관한 연구 (A Study on the Weldability of S45C Medium Carbon Steel for Machine Structural Use by Nd:YAG Laser)

  • 방한서;김영표;일본명
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 2001년도 추계학술발표대회 개요집
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    • pp.134-139
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    • 2001
  • This paper describes the weldability of JIS S45C medium carbon steel (same material with KS SM45C and SAE 1045) for machine structural use by Nd:YAG laser. This material have a limitation to the industrial application in spite of good mechanical characteristics. This is due to its difficult welding work from high carbon contents. We therefore have investigated laser weldability of this material to extend the application of medium carbon steel. The results of this study provide application possibility of Nd:YAG laser welding for medium carbon steel.

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최근 10년간 강원도내 소아의 혈중 칼슘농도의 변화 (The Change of Serum Calcium Level during Last Decade in Kangwondo, Korea)

  • 전고운;심준용;이재승;김병길;남궁미경
    • Childhood Kidney Diseases
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    • 제6권2호
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    • pp.188-197
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    • 2002
  • 목적 : 최근 우리 나라의 음식물에는 칼슘을 보강한 제품이 널리 유통되고 있고, 사람들의 칼슘섭취에 대한 인식도 달라지고 있다. 최근 본원에서는 혈뇨를 주소로 내원하여 검사를 시행한 환아에게서 고칼슘뇨증 소견에 합당한 경우가 늘어나 이에 본원을 방문한 소아를 대상으로 최근 10년간의 혈중 칼슘치와 그에 관계된 혈중 ALP, 크레아티닌, 나트륨, 칼륨, 혈중 중탄산염과 요중 pH와의 상관관계 및 변화 양상을 비교 분석해 보았다. 대상 및 방법 : 1991년, 1992년과 2000년, 2001년 본원에서 편도선 및 아데노이드 제거수술과 고환 고정술 및 탈장 봉합술을 시행한 환아를 대상으로, 혈중 칼슘, ALP, 크레아티닌, 나트륨, 칼륨, 중탄산염과 요중 pH 값을 조사하였다. 연도군 별로는 1991년, 1992년에 355명의 환아와 2000년, 2001년에 488명의 환아를 대상으로 하여 각 연령군 간에 t-test를 통해 분석하였다. 결과 : 2001년도군에서는 칼슘, ALP, 크레아티닌, 나트륨, 칼륨, 소변 pH의 값이 각각 $9.91{\pm}0.50\;mg/dL,\;248.58{\pm}94.98\;U/L,\;0.61{\pm}0.14\;mg/dL,\;138.64{\pm}2.22\;mM/L,\;4.35{\pm}0.40\;mM/L,\;6.18{\pm}0.86$으로 1991년도군의 각 각의 값인 $9.13{\pm}0.68;mg/dL,\;198.26{\pm}79.34\;U/L,\;0.433{\pm}0.18\;mg/dL,\;137.86{\pm}2.67\;mM/L,\;4.22{\pm}0.36\;mM/L,\;5.83{\pm}0.95$에 비해 모두 P-value 0.05이하의 유의한 증가를 보였고, 혈중 중탄산염은 2001년도군에서는 $23.64{\pm}2.57\;mM/L$로 1991년도군의 $24.60{\pm}2.23\;mM/L$에 비해 P-value 0.000으로 통계적으로 유의한 감소를 보였다. 각 연령별, 성별 비교에서도 같은 양상을 보인다. 결론 : 최근 10년간의 강원도 소아의 혈중 칼슘치는 의미 있게 증가하였다. 이는 칼슘의 경구 섭취량의 증가에 기인한 것이 큰 영향을 미친다고 사료되며 이에 대한 재인식과 교육이 필요하다고 생각한다.

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