크롬강에서 석출한 M23C6 형 복합탄화물의 조대화 특성에 관한 연구

노용식,이상윤 대한금속재료학회 1985 대한금속재료학회 학술대회 개요집 Vol.1985 No.0

Sursulf처리후 고주파 표면경화된 저탄소강의 경도 및 마모특성에 미치는 Sursulf처리시간 및 고주파 경화 이송속도의 영향

노용식,김영희,이평호,신호강,이상윤 ( Y . S . No,Y . H . Kim,P . H . Lee,H . K . Shin,S . Y. Lee ) 한국열처리공학회 1989 熱處理工學會誌 Vol.2 No.2

This study has been performed to investigate into some effects of the Sursulf treatment time and the traveling speed of surface hardening treatment on the hardness and the wear characteristics by applying the combined heat treating techniques of Sursulf process followed by induction hardening treatment to mild steel. It has been shown that increasing the Sursulf treatment time increases the case depth, but both hardness and wear resistance are not considerably improved. When the combined heat treating technique of high frequency induction heating after Sursulf treatment is applied, an improvement in case depth as well as wear resistance is obtained. In particular, the hardness in diffusion zone is greatly increased due mainly to the formation of martensite and possibly lower bainite. Iron oxides formed during induction heating and subsequent water spray cooling in the outermost part of compound layer may be considered to cause some increases in hardness and wear resistance.

혁신도시 이전공공기관 종사자의 거주이전 결정요인 분석

노용식,이영환 한국융합학회 2021 한국융합학회논문지 Vol.12 No.2

본 논문은 인구이동의 이론에 따라 혁신도시 이전기관 종사자 구성세대의 이동 요인을 추출하고 요인들의 상대 적 영향을 설명하고자 하였다. 개인 및 가구변수와 거리와 인구의 중력모델, 네트워크변수, 지방재정․지역경제․교육․문화․ 주택 등 전입지와 전출지의 상대적 유용성판단의 지역변수를 선정하였다. 종속변수의 이산성과 데이터의 구조를 감안하 여 다층로짓모형 구축하였고 최종모형은 확률절편모델을 선택하였다. 실증분석 결과 개인․가구변수에서는 남성보다 여 성이, 30대 미만보다는 30-40대가, 대졸이하보다는 박사학위취득자가, 취업한 배우자보다는 미취업배우자의 이전종사 자가 주민등록을 더하였다. 지역변수에서는 중력모델과 관련하여 기관까지 거리가 멀수록 주민등록을 더 한 반면, 이전 시기(t-1)의 일반 유입이 클수록 주민등록 이전을 덜 하였다. 지역간 상대적 유용성과 관련하여 전입지의 지역경제, 교 육환경, 주거환경이 클수록 이전을 더하였고 지방재정의 경우는 반대였다. This paper identify factors of migration of employees’ household who work for relocated public institutions. As a factors of migration, we consider individual and household characteristics, the gravity model of distance and population and so on. Considering discrete dependant variable and structure of data, we employ the logistic multilevel model and random intercept model. The result indicates employees’ who are female, 30s and 40s, higher education level(PhD) and whose spouse are unemployed tend to transfer their residential registration to new city near relocated public institution. Regarding regional variable, the distance from employee’s previous residential location and number of migration of prior year are statistically significant. Also the model indicate regional economy, educational and residential environment of new city influence employee’s decision for transferring residential registration.

질소-프로판-공기분위기에서 저탄소 합금강의 침탄시 내부산화 특성에 미치는 가스조성의 영향

노용식,김성만,김영희,김한군,이상윤 ( Y . S . Roh,S . M . Kim,Y . H . Kim,H . K . Kim,S . Y . Lee ) 한국열처리공학회 1991 熱處理工學會誌 Vol.4 No.4

This study has been performed to investigate into the internal oxidation characteristics of low carbon steel with respect to the added amount of air in nitrogen-propane atmosphere after gas carburizing for various times at 930℃. The results obtained from the experiment are as follows ; (1) Optical micrographs have shown that the internal oxidation is unlikely to occur in the gas atmosphere without air and that oxidized zone in the outer surface layer is formed in the gas atmosphere with air revealing that the depth of oxidized zone increases with increasing the added amount of air. (2) The formation of internally oxidized zone in the outer surface layer has been found to be inhibited as Ni content increases, i, e, the amount of alloying element increases. (3) The depth of oxidation has been measured to increase with almost parabolically gas carburizing time of up to 6 hours.

유동상 침탄시 저탄소 합금강의 침탄능에 미치는 Ni 함량 및 분위기 가스압력의 영향

노용식,김영희,이상윤 ( Y . S . Roh,Y . H . Kim,S . Y . Lee ) 한국열처리공학회 1990 熱處理工學會誌 Vol.3 No.3

This study has been conducted to establish the carburizing characteristics of low carbon alloy steels with varying amount of Ni element gas-carburized for 2hours at 930℃ in an atmosphere of 94% N₂-6% C₃H_8 gas mixture with some changes in gas pressure passing throgh the diffusion plate in the fluidized-bed furnace. The results obtained from the experiment are as followes : (l) Optical micrograph has shown that the carburized layer consists of retained austenite and plate martensite and that retained austenite increases as the pressure of gas mixture passing through the diffusion plate as well as Ni content increase. (2) Chemical analysis has shown that carbon potential increases and carburizability is also improved due to a less degree of fluidization as the pressures of gas mixtures passing through the diffusion plate increase, resulting in, however, a severe formation of soot, and the gas pressure is necessarily regulated. (3) It has been revealed that carbon concentration hardness values at a given distance measured from the surface within the carburized case. Increase with increasing the pressure of gas mixtures passing through the diffusion plate and decrease with increasing Ni content. (4) The effective case depth has been shown to almost linearly increase as the pressure of gas mixtures passing through the diffusion plate is increased and to decrease with increasing Ni content.

질소-프로판 가스 분위기에서 유동상 침탄 처리시 침탄 특성에 미치는 공기 첨가량의 영향

노용식,이상윤 동아대학교 공과대학 부설 한국자원개발연구소 1990 硏究報告 Vol.14 No.2

This study has been conducted to establish she variation of micro-hardness values and carbon concentrations with various added amounts of air in 0.2% carbon steel gas-carburized in a fluidized-bed furnace for 2,4 and 6 hours at 930℃ in various gas atmospheres of 6% propane, nitrogen and air. The results obtained from the experiment are as follows : (1) Chemical analysis has shown that changes in carbon potential decrease slowly as the amount of air addition is increased up to 18%, whereas their reduction rate increases rapidly with increasing the amount of air more than 24%. (2) Hardness measurement has revealed that the variation of hardness values and carbon cocentration with distance measured from the surface within the carburized case is little change for the air addition of less than 18%, whilst hardness values and carbon concentration decrease very rapidly for the air addition of more than 24%. (3) The effective case depth has been shown to be little change for the air addition of than 18%. The reduction rate of effective case depth, however, has been measured to increase abruptly for the air addition of more than 24%.

식품제조업의 지역경제 효과

노용식 서울대학교 환경대학원 2015 環境論叢 Vol.55 No.-

유동상 가스 침탄시 내부산화특성에 미치는 저탄소강의 Ni함량 및 분위기 가스 조성의 영향

노용식,이상윤 동아대학교 공과대학 부설 한국자원개발연구소 1990 硏究報告 Vol.14 No.2

This study has been performed to investigate into the internal oxidation characteristics of steels containing various Ni content with respect to the added amount of air in nitrogen-propane atmosphere after gas carburizing for various times at 930℃. The results obtained from the experiment are as follows ; (1) Optical micrographs have shown that the internal oxidation is unlikely to occur in the gas atmosphere without air and that oxidized zone in the outer surface layer is formed in the gas atmosphere with air, revealing that the depth of oxidized zone increases with increasing the added amount of air, considerably more than 18% of air. (2) The formation of internally oxidized zone in the outer surface layer has been found to be inhibited as Ni content increases, i.e. the amount of alloying element increases. (3) The depth of oxidation has been measured to increase with almost linearly increasing gas carburizing time of up to 6 hours.

독일 추크슈피체 산악열차와 지역경제 활성화

노용식,최유,권영섭 국토연구원 2017 국토 : planning and policy Vol.431 No.-

크롬 鋼에서 析出된 M23C6形 複合 炭化物의 粗大化 特性에 관한 硏究

李相允,盧用植 東亞大學校 1989 東亞論叢 Vol.26 No.1

This study has been carried out to elucidate the Ostwald Ripening behavior of M?C? type complex carbide precipitated in 13.5% Cr steel during spheroidizing treatment at a range of 650℃ to 710℃ after standarding the initial particle size distribution. The results obtained from the experiment are as follows. 1. Average particle size measurements have shown that based on the results obtained from the relation between the log of average particle radius and the log of spheroidizing time for three different temperatures 650℃, 680℃ and 710℃ the radius of (Cr, Fe)?C? complex carbide is proportional to the cubic root of spheroidizing time. 2. It has been found from the measurements of average particle radius and the number of particles per unit area that the average value of activation energy is obtained to be 53.5Kcal/mole, which shows that the coarsening of complex carbide precipitates is governed by the interdiffusion mechanism of Fe, Cr and C atoms. 3. Complex carbide particle size distribution curves appears to approach the steady state distribution curve obtained for diffusion controlled mechanism and does not reach it within a spheroidizing time of 1800 hours. 4. X-ray diffraction analysis has shown that complex carbide precipitated during spheroidizing treatment is (Cr, Fe)?C? and that for the same spheroidizing time values for lattice parameter increase with increasing spheroidizing temperature.