• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.401-402
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• 2002

Diesel engines have many sliding parts with solid body contact. For example, a piston-ring and a cylinder bore, a valve and a valve-seat, a cam and a valve tappet. These parts have a severe wear problem. during engine life times. During these times, the valve tappet has abnormal wear such as scuffing and pitting due to a high hertzian contact stress between the cam and the tappet. Excessive wear problems frequently occur to both the cam and the tappet. To solve these problems, we developed an advanced wear resistant tappet. The developed tappet consisted of a hard-metal wear part and a steel body. To increase a bonding strength, those two parts, were directly bonded to each other. Also to decrease a bonding temperature, we developed the composition of Ni-binder materials in the hard metal. To estimate the wear characteristics of the newly developed tappet, we performed wear tests and engine dynamo tests in order to compare them with a conventional Fe-base tappet. As a result, the newly developed tappet has better wear characteristics than those of the conventional tappet. In addition, we performed a 100,000km field-test, and the newly developed tappet showed much improved wear resistance.

• 한국지역지리학회지
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• 제11권6호
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• pp.543-558
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• 2005

이 연구는 산업클러스터와 산업네트워크론의 관점에서 부산지역 기계 금속산업의 실태와 특성을 조사, 분석하였다. 이를 위해 산업네트워크와 산업클러스터의 관계를 재설정하고 산업네트워크의 구성부문들을 분석하는 이론적 작업을 시도하였다. 또, 부산지역 기계 금속산업의 발전과정 및 실태와 관련된 각종 통계 분석 작업과 함께, 이 분야의 기업들을 대상으로 설문조사를 실시하였다. 이 분석 결과로 다음의 세 가지 결론이 도출되었다. 첫째 부산지역 기계 금속산업은 비록 규모가 크지 않다고 하더라도 독자적인 산업클러스터를 형성하고 있다. 그것은 동남권 기계 금속산업벨트의 하위 구성요소로서 존재하기도 하지만 그 이전에 명확히 구별되는 국지적 산업클러스터를 형성하고 있다. 둘째, 부산지역 기계 금속산업의 기술수준 및 경쟁력은 여전히 낮은 수준에 머물러 있다. 이 지역의 업체들은 낮은 수준의 기술과 경쟁력의 균형상태에서 국지적 네트워크를 맺고 있는 것이다. 셋째, 부산지역 기계 금속산업클러스터를 현재의 정체상태에서 도약하여 고도화를 이루기 위해서는 선도기술형 산업클러스터로의 이행이 필요하며, 이 산업분야의 선도기술기업을 적극적으로 유치하거나 창업하도록 지원하는 것이 요구된다.

• Journal of Preventive Medicine and Public Health
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• 제22권3호
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• pp.337-354
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• 1989

In order to evaluate the noisy environment and hearing loss of workers served in noisy working environment, the author investigated 212 manufacturing industries located in Ulsan Industrial District that could be observed for 3 successive years from 1986 to 1988. The obtained results were as follows: 1. There was increased tendency in the number of workers served in noisy working environment and that of examined of hearing loss for three years. 2. In the noise level of working environment, the number of industries less than 89dB(A) was increased every year, while more than 90dB(A) was in decreasing tendency. 3. Mean hearing loss by frequency was the most prominent in 4,000Hz, the level of hearing loss was in increasing tendency yearly, and that of left eat was higher than right ear in almost all type of industry. 4. In 1986, the level of hearing loss by type of industry was highest in manufacture of electric and electronic, and followed by paper and plywood, and metal products in right ear: that was in the order of manufacture of electric and electronic, metal products and textile products in left ear. In 1987, that was in the order of manufacture of metal products, machinery and others in right ear, and metal products, machinery and food stuff in left ear in 1988, manufacture of others, food stuff and machinery in both ear. 5. In hearing loss by service duration, right ear of 5-9 years group was higher than that of less than 5 years in 1987, whereas in 1988, the longer in service duration, the higher in the level of hearing loss in both ear. 6. In 1986, 1987 and 1988, the prevalence rate of noise-induced hearing loss were showed increasing tendency as 0.4% ,0.8% and 1.5% , respectively, and manufacture of textile products was highest(1.0%) in 1986, machinery(1.2%) in 1987 and others(2.8%) in 1988. 7. The proportion of grade E in early loss index were 76.1% (1986), 78.2% (1987) and 80.5% (1988) in left ear, 75.9% (1986), 76.4% (1987) and 75.9% (1988) in right ear.

• 소성∙가공
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• 제8권3호
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• pp.301-301
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• 1999

Austenitic stainless steels such as AISI 316L have been used in equipment in which fluid flows at high speeds which can induce cavitation erosion on metallic surfaces due to the collapse of cavities, where the collapse is caused by the sudden change of local pressure within the liquid. Usually AISI 316L is susceptible to cavitation erosion. This research focuses on developing a better material to replace the AISI 316L used in equipment with high speed fluid flow, such as impellers. The effects of Rare Earth Metal (REM) additions on the cavitation erosion-corrosion resistance of duplex stainless steels were studied using metallographic examination, the potentiodynamic anodic polarization test, the tensile test, the X-ray diffraction test and the ultrasonic cavitation erosion test. The experimental alloys were found to have superior mechanical properties due to interstitial solid solution strengthening, by adding high nitrogen (0,4%), as well as by the refinement of phases and grains induced by fine REM oxides and oxy-sulfides. Corrosion resistance decreases in a gentle gradient as the REM content increases. However, REM containing alloys show superior corrosion resistance compared with that of other commercial alloys (SAF 2507, AISI 316L). Owing to their excellent mechanical properties and corrosion resistance, the alloys containing REM have high cavitation erosion-corrosion resistance.

• 소성∙가공
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• 제8권3호
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• pp.289-289
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• 1999

This paper describes the investment casting of TiAl alloys. The effects of mold material and mold preheating temperature for the investment casting of TiAl on metal-mold interfacial reaction were investigated by means of optical micrography, hardness profiles and an electron probe microanalyzer. The mold materials examined were colloidal silica bonded ZrO₂, ZrSiO₄, A1₂O₃and CaO stabilized ZrO₂. When compared with conventional titanium a1loy, the high aluminum concentration of TiAl alloys helps to lower their reactivity in the molten state. The A1₂O₃mold is a promising mold material for the investment casting of TiAl in terms of the thermal stability, formability and cost. Special attention need to be paid to thermal stability and mold preheating when developing the investment calling of TiAl alloys.

• 한국산업보건학회지
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• 제6권2호
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• pp.249-264
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• 1996

This study was conducted for the purpose of obtaining the fundamental data on improvement of working environment and contributing to health improvement of workers who dealed with metal by assessing the metal concentration in air of industries located in Chang-Won Industrial Complex. Authors measured the concentration of metals(Al, Cd, Cr, Cu, Mn, Ni, Pb, Sn and Zn) is the air to 25 working processes of 73 industries by flame atomic absorption spectrometry from February to December 1994. Personal air sampler was used for air sampling with mixed cellulose-ester membrane filter. The results were as follows : 1. The geometric means(range) of metal concentration; 1) Al: $0.1505mg/m^3$ ($0.0147-18.6100mg/m^3$) 2) Cd: $0.0077mg/m^3$ ($0.0003-7.0710mg/m^3$) 3) Cr: $0.0163mg/m^3$ ($0.0013-1.1510mg/m^3$) 4) Cu: $0.0097mg/m^3$ ($0.0009-0.4950mg/m^3$) 5) Mn: $0.0412mg/m^3$ ($0.0006-4.7877mg/m^3$) 6) Ni: $0.0088mg/m^3$ ($0.0001-1.0170mg/m^3$) 7) Pb: $0.0152mg/m^3$ ($0.0015-0.4499mg/m^3$) 8) Sn: $0.0486mg/m^3$ ($0.0037-0.1500mg/m^3$) 9) Zn: $0.1911mg/m^3$ ($0.0122-8.2920mg/m^3$) 2. The geometric mean of lead exceeded TWA in assembling process of other general purpose machinery not elsewhere classified products manufacturing industries.

• 기술혁신학회지
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• 제16권2호
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• pp.391-407
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• 2013

본 연구에서는 산업연관표를 통해서 특정연도(1990년) 기술의 진부화 정도를 측정하고, 노동생산성과의 연관성을 밝힘으로써 체화가설(embodiment hypothesis)을 검증한다. 이는 기술에 강한 경제적 의미를 부여한 Salter(1969)의 주장에 근거한 것으로, 경제적 잉여율의 감소를 기술진부화 정도로 보았다. 분석대상은 우리나라 제조업에 속한 주요 업종인 음식료, 섬유의복, 화학, 비금속광물, 철강, 금속제품, 일반기계, 전기전자, 정밀기기, 수송기계 등이다. 연구결과, 우리나라 제조업 전체에 대해서 일률적으로 체화가설의 성립여부를 판단하기는 어려웠다. 그러나 제조업 주요 업종 중 섬유의복, 화학, 비금속광물, 금속제품, 전기전자, 수송기계 등의 산업에서는 체화가설이 성립함을 확인하였다. 즉 이들 6개 산업에서는 기존 자본설비에 현대적인 새로운 자본설비가 연속적으로 도입됨에 따라 특정시점에서 자본설비에 체화되어 도입된 기술은 진부화 하지만, 시현되는 노동생산성은 증가하는 것으로 분석되었다. 따라서 개별기업들은 설비투자에 대한 의사결정 시에 관련설비에 체화된 기술진보에 관한 정보를 적극 고려해야 하며, 정부는 R&D지원 일변도의 정책에서 벗어나 체화기술진보 효과가 큰 산업에 대해서는 설비투자를 지원하는 정책도 고려해야 한다.

• 한국표면공학회지
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• 제52권4호
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• pp.187-193
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• 2019

Electroless Ni-P coatings are widely used in the chemical, mechanical, and electronic industries because of their excellent wear and abrasion resistance. In this study, the effect of $TiO_2$ particles of composite coating was investigated. To improve the corrosion resistance, electroless $Ni-P-TiO_2$composite coating was studied by varying the $TiO_2$ content. The morphology and phase structure of $Ni-P-TiO_2$ composite coatings were analyzed by scanning electron microscopy(SEM), X-ray diffractometry(XRD) and X-ray photoelectron spectroscopy(XPS). The result showed that $Ni-P-TiO_2$composite coating is composed of Ni, P, Ti and O. It exhibits an amorphous structure, high hardness and good corrosion resistance to the substrate. $Ni-P-TiO_2$ composite coatings have higher open circuit potential than that of the substrate, which obtained at $TiO_2$ content of 5.0 g/L optimal integrated properties.

• International Journal of Safety
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• 제2권1호
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• pp.45-49
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• 2003

In this paper, we investigated the relationship between the variables of the industrial accident factors and the manufacturing performances such as production quantity, quality, cost, and delivery. For this investigation, we collected the real data from 30 small/medium-sized manufacturing industries by performing a questionnaire survey and a on-site inter-view with the workers. Thirty industries were made up of 10 from each of the following three industries: metal processing, machinery manufacturing, and chemical products manufacturing. The data analysis was made using SPSS PC+. Based on the result of the analysis, we came to the tentative conclusion that only two variables such as work skill and load affected all four manufacturing performances and the rest of them two or three performances.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.918-920
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• 2006

Metal sulfide powders such as MnS, $MoS_2$ and FeS are simply used to the machinery processing improvement agent and solid lubricant in powder metallurgy industrial. And then, metal sulfide powders have received relatively little attention from powder metallurgy. Recently, the portable machine is one of the important interfaces between human or human and electronic machine. With the increase of the intelligent activity, the social and industrial demands for information display device and power source are increasing. The transition metal sulfide materials (FeS, ZnS) have received considerable attention due to the large variety of its electric, optical and magnetic properties. Among the metal sulfide, $FeS_2$ is appealing superior material for applications in $Li-2^{nd}$ battery because of high capacity. ZnS is also a famous phosphor material with various luminescence properties, such as photoluminescence (PL) and electroluminescence (EL). So generally used in the fields of display, sensors and laser. Metal sulfide materials, therefore, are provided for most widely application in all industries. In recent years, material researchers have become increasingly interested in studying with synthesis of metal sulfide.