용사된 도막의 내식성에 관한 전기화학적 평가

신중하(Joong-Ha Shin),오민석(Min-Seok Oh),이명훈(Myung-Hoon Lee),김윤해(Yun-Hae Kim),이성렬(Sung-Yul Lee),문경만(Kyung-Man Moon) 한국마린엔지니어링학회 2010 한국마린엔지니어링학회 학술대회 논문집 Vol.2010 No.4

There are many surface protection methods for steel structures under severely corrosive environment, one of them, metallizing(thermal spray) is a available protection method which is comparatively and recently developed for surrface protection of various steel structures. However coating film obtained by spraying is to be needed increasingly more good corrosion resistance due to accelerating of environmental contamination. In this study, coating films(DFT:200㎛) are made with arc spray with wire metal both of pure zinc or aluminum and their alloy metals with some ratio(Al:Zn=85:15, 85:5). And corrosion resistance of their films is investigated with electrochemical methods in seawater solution. Pure aluminum film showed a somewhat good corrosion resistance among those of other films and good corrosion resistance was also observed at alloy films with some ratio compared to pure zinc film. Especially film of galvarium spray(Al:Zn=85:15) showed not good corrosion resistance than that of pure aluminum film in seawater solution. Morphology of corroded surface of pure zinc film appeared the pattern like intergranlar corrosion, however film of pure aluminum showed a general corrosion pattern.

반동도에 따른 증기터빈의 설계 및 성능해석

신중하(Jung Ha Shin),이근식(Geun Sik Lee) 대한기계학회 2011 大韓機械學會論文集B Vol.35 No.12

반동도에 따른 증기터빈의 설계 및 성능 해석을 컴퓨터 시뮬레이션으로 수행하였다. 깃 각도와 출구면적, 노즐면적과 같은 설계변수들과 터빈동력, 선도효율, 축방향 추력과 같은 성능변수들을 반동도에 따라 나타내었다. 추가적인 설계 및 성능변수에 대한 정보를 제공하기 위하여, 깃 각도와 터빈동력, 선도효율, 축방향 추력과 같은 주된 설계 및 성능변수들을 유동계수(주속도에 대한 축방향속도)의 함수로 제시하였다. 터빈동력, 선도효율을 최대로 하는 반동도 및 유동계수가 존재함이 밝혀졌으며, 반동도가 증가함에 따라 동익의 깃 형상은 대칭형으로부터 많이 벗어남을 보여주었다. Design and performance analysis of a steam turbine for variations of degree of reaction were performed by computer simulation. Design parameters such as blade angles, exit areas, and heights of the nozzle and moving blade were represented as functions of the degree of reaction. The main performance factors such as turbine power, diagram efficiency, and axial thrust were also expressed in terms of the degree of reaction. For further information about the design and performance, the blade angles and main performance factors were investigated as functions of the flow coefficient. The turbine power and diagram efficiency reached a maximum value for a given degree of reaction and flow coefficient, and the symmetric shape of the moving blade showed distortion as the degree of reaction was increased.

용사 도막의 내식성에 관한 전기화학적 평가

신중하 ( Joong Ha Shin ),문경만 ( Kyung Man Moon ) 한국부식방식학회(구 한국부식학회) 2010 Corrosion Science and Technology Vol.9 No.6

Many surface protection methods have been developed to apply for constructional steels used under severe corrosive environment. Thermal spray coating has been known to be an attractive technique due to its relatively high coating speed. Furthermore high corrosion resistance of coated film with thermal spray is required to expand its application. Four types of coated films(DFT: 300 um) such as pure zinc, pure aluminum and two Al-Zn alloy (Al:Zn=85:15 and Al:Zn=95:5) onto the carbon steel (SS401) were prepared with arc spray, and the corrosion behavior of their samples were evaluated by electrochemical method in this study. Pure aluminum sample showed high corrosion resistance behavior exposed to sea water solution and pure zinc and alloy (Al:Zn=95:5) samples followed pure aluminum sample. The other alloy(Al:Zn=85:15) so called galvalume coated onto the carbon steel ranks the 4th corrosion resistance in this study. The results of porosity ratio of those samples by observation are well matched with the electrochemical data.

용사 도막의 내식성에 관한 전기화학적 평가

문경만,신중하,이명훈,이성렬,김윤해,Moon, Kyung-Man,Shin, Joong-Ha,Lee, Myung-Hoon,Lee, Sung-Yul,Kim, Yun-Hae 한국마린엔지니어링학회 2010 한국마린엔지니어링학회지 Vol.34 No.5

There are many surface protection methods for numerous steel structures being used under severely corrosive environment, one of them, metallizing(thermal spray) is a available protection method which is comparatively and recently developed for surrface protection of various steel structures. However coating film obtained by spraying is to be needed increasingly more good corrosion resistance due to accelerating of environmental contamination. In this study, coating films(DFT:$200{\mu}m$) are performed with arc spray by wire metal and their types of films are pure zinc, pure aluminum, alloy film(Al:Zn=85:15) and alloy film(Al:Zn=95:5). And corrosion resistance of their films was investigated with electrochemical methods in seawater solution. Pure aluminum film showed a relatively somewhat good corrosion resistance compared to among those of other films and alloy films also showed a good corrosion resistance compared to pure zinc film. Especially it was observed that pure aluminum film showed a comparatively good corrosion resistance than that of alloy film named as galvarium spray(Al:Zn=85:15) in seawater solution. Morphology of corroded surface of pure zinc film appeared the pattern like intergranlar corrosion, however films of pure aluminum and alloy metal showed a general corrosion pattern. 가혹한 부식환경 하에 사용되어 지고 있는 다양한 강구조물에 대해서 많은 표면방식법이 있다. 그 중의 한방법인 용사는 다양한 강구조물의 표면방식을 위하여 비교적 최근에 개발된 유용한 방식법이다. 그러나 용사피막도 환경오염의 가속화에 따라 점차 더욱 좋은 내식성을 필요로 하고 있다. 본 연구에서는 아아크 용사에 의해서 도막두께 $200{\mu}m$의 피막을 만들었으며, 피막의 종류는 순 아연,순 알류미늄, 합금피막(Al:Zn=85:15) 및 (Al:Zn=95:5)의 합금피막이었다. 그리고 이들 피막의 내식성을 해수용액에서 전기화학적인 방법으로 고찰 하였다. 순 알류미늄 피막은 다른 피막에 비해서 비교적 상당히 좋은 내식성을 보였다. 그리고 합금피막도 역시 순 아연피막에 비해서 좋은 내식성을 보였다. 특히 순 알류미늄 피막은 갈바륨 용사라고 알려진 합금피막(Al:Zn=85:15)보다 해수용액에서 내식성이 상대적으로 좋았음이 관찰되었다. 순 아연의 부식된 표면양상은 입게부식의 형태를 나타내었으나 순 알류미늄과 합금피막은 균일부식의 형태를 나타내었다.

인천국제공항 제4활주로 건설 타당성 연구

최동엽,박성도,신중하,정찬혁 한국항공운항학회 2019 한국항공운항학회지 Vol.27 No.2

Although This study is to produce various considerations for the proper time and feasibility of new runway with Incheon international airport 4th runway development case. In order to validate the feasibility of runway development, it is main considerations to be increased airport capacity for accommodating increase air traffic demand, secure stable airport operation without degrading service level, cope with emergency situation and maintain competitive among competitive airports which are developing new runway. Conclusionally, to develop new runwlay at the proper time for sustainable and stable airport operation without stop is the best way of maintaining competitiveness among foreign competitive airports

인천공항 4단계 건설사업 제4활주로 포장설계 사례 분석

김동철,이동혁,신중하,장찬혁 한국도로학회 2021 한국도로학회지 Vol.23 No.2

인천국제공항 제4활주로 광폭편대(Echelon) 포장공법

김동철,이동혁,신중하,이성재 한국도로학회 2020 한국도로학회지 Vol.22 No.4

용사 도막의 내식성에 관한 전기화학적 평가

문경만(Kyung-Man Moon),신중하(Joong-Ha Shin),이명훈(Myung-Hoon Lee),이성렬(Sung-Yul Lee),김윤해(Yun-Hae Kim) 한국마린엔지니어링학회 2010 한국마린엔지니어링학회지 Vol.34 No.4

가혹한 부식환경 하에 사용되어 지고 있는 다양한 강구조물에 대해서 많은 표면방식법이 있다. 그 중의 한방법인 용사는 다양한 강구조물의 표면방식을 위하여 비교적 최근에 개발된 유용한 방식법이다. 그러나 용사피막도 환경오염의 가속화에 따라 점차 더욱 좋은 내식성을 필요로 하고 있다. 본 연구에서는 아아크 용사에 의해서 도막두께 200㎛의 피막을 만들었으며, 피막의 종류는 순 아연,순 알류미늄, 합금피막(Al:Zn=85:15) 및 (Al:Zn=95:5)의 합금피막이었다. 그리고 이들 피막의 내식성을 해수용액에서 전기화학적인 방법으로 고찰 하였다. 순 알류미늄 피막은 다른 피막에 비해서 비교적 상당히 좋은 내식성을 보였다. 그리고 합금피막도 역시 순 아연피막에 비해서 좋은 내식성을 보였다. 특히 순 알류미늄 피막은 갈바륨 용사라고 알려진 합금피막(Al:Zn=85:15)보다 해수용액에서 내식성이 상대적으로 좋았음이 관찰되었다. 순 아연의 부식된 표면양상은 입게부식의 형태를 나타내었으나 순 알류미늄과 합금피막은 균일부식의 형태를 나타내었다. There are many surface protection methods for numerous steel structures being used under severely corrosive environment, one of them, metallizing(thermal spray) is a available protection method which is comparatively and recently developed for surrface protection of various steel structures. However coating film obtained by spraying is to be needed increasingly more good corrosion resistance due to accelerating of environmental contamination. In this study, coating films(DFT:200㎛) are performed with arc spray by wire metal and their types of films are pure zinc, pure aluminum, alloy film(Al:Zn=85:15) and alloy film(Al:Zn=95:5). And corrosion resistance of their films was investigated with electrochemical methods in seawater solution. Pure aluminum film showed a relatively somewhat good corrosion resistance compared to among those of other films and alloy films also showed a good corrosion resistance compared to pure zinc film. Especially it was observed that pure aluminum film showed a comparatively good corrosion resistance than that of alloy film named as galvarium spray(Al:Zn=85:15) in seawater solution. Morphology of corroded surface of pure zinc film appeared the pattern like intergranlar corrosion, however films of pure aluminum and alloy metal showed a general corrosion pattern.

사다리꼴 형상 그루빙의 공항 활주로 적용성 평가 연구

조남현,김동철,피승우,신중하 한국항공운항학회 2021 한국항공운항학회지 Vol.29 No.4

This study is to evaluate the applicability and performance of trapezoidal-shaped grooves on domestic airport runways. For this, the constructability, drainage performance, and friction resistance characteristics of trapezoidal-shaped grooves compared to square-shaped grooves were evaluated through test construction on pavement at Incheon Airport. As a result of the test construction, the trapezoidal-shaped grooves satisfies the required geometry standards and tolerance, and secured a macrotexture that was 25% improved compared to the square-shaped grooves. It was confirmed that trapezoid-shaped grooves secured drainage performance of more than 7-9%, and surface friction performance improved compared to existing grooves when the surface of the pavement was wet as the test speed increased in the dry state. In addition, after trapezoidal-shaped grooves was installed on the RWY 16R/34L of Incheon Airport, the friction coefficient was 0.84, which satisfies the design level of the new runway surface of 0.82 at the test speed.

반동도에 따른 증기터빈의 설계 및 성능해석

이근식(Geun Sik Lee),신중하(Jung Ha Shin) 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.5

반동도에 따른 증기터빈의 설계 및 성능 해석을 컴퓨터 시뮬레이션으로 수행하였다. 깃 각도와 출구면적, 노즐면적과 같은 설계변수들이 반동도에 따라 제시되었다. 터빈동력, 선도효율, 축방향 추력과 같은 성능변수들을 반동도에 따라 제시하였다. 추가적인 설계 및 성능변수에 대한 정보를 제공하기 위하여, 깃 각도와 터빈동력, 선도효율, 축방향 추력과 같은 주된 성능변수들을 유동계수(주속도에 대한 축방향속도)의 함수로 제시하였다. 터빈동력, 선도효율을 최대로 하는 반동도 및 유동계수가 존재함이 밝혀졌으며, 반동도가 증가함에 따라 동익의 깃 형상은 대칭형으로부터 많이 벗어남을 보여주었다. Design and performance analysis of a steam turbine for variations of degree of reaction were performed with aid of computer simulation. Design parameters such as blade angles and exit areas and heights of nozzle and moving blade were represented as a function of degree of reaction. Main performance factors such as turbine power, diagram efficiency, and axial thrust were expressed in terms of degree of reaction. For further information of design and performance, blade angles and main performance factors were investigated as a function of flow coefficient. It was found that there exist maximum values of turbine power and diagram efficiency for both a degree of reaction and a flow coefficient and moving blade has a tendency to deviate from symmetric shape as a degree of reaction is increased.