• 열처리공학회지
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• 제34권6호
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• pp.272-280
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• 2021

The influence of acetylene flow rates on the carburizing behavior of an AISI 4115 steel in 1 ton-class mass production-type vacuum carburizing furnace has been studied through microstructure, carbon concentration, hardness analyses. The AISI 4115 steels were carburized with various flow rates (20, 32.7, 60 l/min) and locations in the furnace (top, center, bottom) at 950℃. The acetylene flow rate played an important role in controlling the carburizing properties of carburized samples, such as effective case depth and uniformity carburizing according to location in the furnace. At an acetylene flow rate of 20 l/min, the carburized samples had a shallow average hardened layer (0.645 mm) compared to the target hardening depth (1 mm) due to low carbon flux and spatial uniformity of carburization (17.8%) in the furnace. At a flow rate of 60 l/min, the carburized samples showed an average hardened layer (1.449 mm) deeper than the target hardening depth and had the spatial uniformity of carburization (98.8%). In particular, at a flow rate of 32.7 l/min, the carburized samples had an average hardened layer (1.13 mm) close to the target hardening depth and had the highest carburizing uniformity (99.1%). As a result, an appropriate flow rate of 32.7 l/min was derived to satisfy the target hardening depth and to have spatial uniform hardened layer in the furnace.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 추계 학술논문 발표대회
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• pp.161-162
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• 2017

As the use of cement increases with the development of modern society along with the increase of buildings, environmental pollution intensifies and researches on industrial byproducts are continuing. Research on blast furnace slag and fly ash as industrial byproducts is increasing, and research on industrial byproducts such as polysilicon sludge and paper ash used in this study is increasing. Blast furnace slag, which is one of the industrial byproducts, has been widely studied as a material used with cement. However, in this study, we fabricated lightweight matrix of polysilicon sludge and paper ash replaced based on blast furnace slag, and performed SEM analysis.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.1068-1071
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• 2002

In this study, first, we show that the furnace process which requires maintaining high temperature is effected grievously by the temperature of surrounding air. Second, an alternative which maintains the relatively constant temperature dispersion surrounding the furnace and at the same time has economical advantages will be proposed.

• 대한기계학회논문집B
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• 제24권11호
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• pp.1549-1554
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• 2000

A new method to determine the total heat exchange factor was proposed for the prediction of billet temperature in a reheating furnace. This method employed the squared of the difference between measured and predicted temperatures as an objective function. The real billet temperature in a walking beam type reheating furnace with 19.75m of its effective length was directly measured by thermocouples. The present method was validated by showing that the predicted billet temperature was in a good agreement with the measured one.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2011년도 전력전자학술대회
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• pp.498-499
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• 2011

In this paper, the fundamental features of the arc stability DC arc furnace have been investigated, from the converter point of view. To compare of measurement arc data from DC arc furnace and the advanced arc simulations of magneto-hydrodynamics (MHD) and the well known Cassie-Mayr arc model have been extensively used. The MHD based arc simulation has been validated in the subcomponent level, for the free burning arc set up in the laboratory. The arc simulation predicted the arc voltage for different currents with the accuracy which satisfies engineering requirements. It has been shown that the arc current steepness at current zero determines the arc stability, and the associated peak arc resistance can be used as its quantitative measure. Based on the presented insight into the DC arc stability, a converter topology solution which realizes an optimal arc stability has been proposed. The main results presented in this paper provide a design guideline for the future DC arc furnace converter topology developments.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 춘계 학술논문 발표대회
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• pp.173-174
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• 2017

Recently, many experiments using industrial by-products have been going on in Korea and abroad. Most of the studies on blast furnace slag and fly ash have been conducted, and the blast furnace slag based two and three component experiments have been conducted in many places. Therefore, this study is an additional study of research using polysilicon sludge and paper ash, which is a study using existing industrial by-products based on blast furnace slag, as strength properties of alkali activator according to kind and mixing ratio and to obtain basic data do.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 추계 학술논문 발표대회
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• pp.135-136
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• 2019

Recently, as the interest in environmental issues increases, the construction industry needs to recycle blast furnace slag, circulating fluidized bed Combustion fly ash, etc. to solve industrial by-products, and to develop artificial stone. In this study, the strength characteristics based on blast furnace slag according to the addition rate of alkali stimulant NaOH are investigated. The experimental results showed that the flexural and compressive strengths increased with the addition of alkali stimulants. Based on these results, it will be presented as a basic research data for the manufacture of artificial stone and will be tested later.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1993년도 추계학술대회 논문집
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• pp.406-410
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• 1993

In the industria; heat treatment fields, some parts of the continous funcae have been automated, but there are not enough interests and achievements for sutomatic charging machine. The automatic charging machine is set up to the industrial mesh belt type continuous furnace which continuously orintermittently charge and extract industrial units for the heat treatments.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2013년도 제46회 KOSCO SYMPOSIUM 초록집
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• pp.121-122
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• 2013

In recent years, the usage of fossil fuels has caused problems of climate change and global warming. Because the combustion of fossil fuels is related to the production of greenhouse gases ($CO_2$, $CH_4$, etc.), new technology in the field of combustion is needed in order to handle the crisis of climate change and the global warming. As one of the efforts to reduce the emission of greenhouse gases, the concept of regenerative oxy-fuel combustion for energy efficiency and carbon capture was suggested, In the current study, the development of an industrial regenerative oxy-fuel combustion furnace was introduced, which has been being performed at Korea Institute of Energy Research (KIER).

• 자원리싸이클링
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• 제19권6호
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• pp.86-92
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• 2010

본 연구는 생산원가 절감은 물론 에너지절감 및 환경보존을 목적으로 산업부산물인 고로슬래그 미분말을 컬러콘크리트의 활용방안으로 모색하고자 색상발현에 어려움이 있는 블랙색상을 선택하여 고로슬래그 미분말의 혼입률에 따른 기초 물성 및 색상발현정도 등을 확인하였다. 산업부산물인 고로슬래그 미분말을 활용한 컬러모르타르는 안료의 혼입시 유동성이 떨어지는 경향을 나타내었으나 입자표면이 산성피막에 의해 치밀하고 매끈하며 잠재수경성의 특성을 가진 고로슬래그 미분말의 혼업률에 비례하여 유동성이 증가하였다. 또한 일반 백색시멘트를 활용한 컬러모르타르보다 초기강도는 낮았으나 혼입시 우수한 장기강도 발현성을 나타내었다. 특히 현재 컬러콘크리트 시공시 색상발현에 가장 적합한 백색시멘트와 비교하여 동동하거나 그 이상의 색상발현성을 나타내었으며 명도 값 -30이하의 우수한 검정색상 발현이 가능하였다.