• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1996년도 추계학술대회논문집
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• pp.166-173
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• 1996

There are kinds of materials for protective heat shield, i.e.Zn-coated steel, AI-coated steel and aluminum alloy sheets. This study compare formability, corrosion resistance, heat protectability, weight, and cost of these materials for heat protective shield. Generally aluminum alloy sheets are less formable than steel sheets, but A1100 alloy sheet shows almost same press quality of steel parts, using the press dies which producing steel parts. The heat shields using aluminum alloy sheet and steel sheet show almost same heat protectibility. It is the conclusion that Zn-coated merit, and AI-coated steel sheet and aluminum alloy sheet can be used to protect functional corrosion in severely corrosive market area. The material cost of AI-coated steel sheet and aluminum alloy sheet for a mid-size car is almost same, so aluminum alloy sheet is more recommendable in the point of weight reduction of vehicle.

• 분석과학
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• 제14권6호
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• pp.494-498
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• 2001

크로메이트를 대체하기 위한 새로운 표면처리 화합물로서 cerium nitrate를 사용하고 Al도금강판에 적용하였을 때, 그 표면의 특성을 정밀하게 분석하였다. 그 결과, cerium nitrate로 처리된 Al도금강판의 표면층에서 cerium은 (+4) 산화 상태와 (+3) 산화 상태의 혼합된 형태로 존재하며 각각의 상대적 비율은 57 % 및 43 %인 것으로 나타났다. 이러한 cerium 화합물의 피막은 Al도금층의 자연산화막과 더불어 도금강판의 표면에 보호 피막을 형성하여 Al도금강판의 표면 부식을 방지하게 된다.

• Corrosion Science and Technology
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• 제2권4호
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• pp.165-170
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• 2003

Atmospheric corrosion behaviors of Zn, Zn-5%Al and Zn-55%A l coated steels have been investigated under cyclic wet-dry environments containing chloride ions. The wet-dry cycle was carried out by alternate exposure to immersion in 0.5 M (or 0.05 M) NaCl solutions and drying at $25^{\circ}C$ and 60 %RH. The polarization resistance $R_p$ and solution resistance $R_s$ were monitored by AC impedance technique. From the obtained $1/R_p$ and $1/R_s$ values, the corrosion rate of the coatings and the Time of Wetness (TOW) were estimated, respectively. Effects of chloride ions and TOW on the corrosion rates of Zn, Zn-5%Al, Zn-55%Al coatings and appearance of red rust (onset of underlying steel corrosion) under wet-dry cycles are discussed on the basis of the corrosion monitoring data.

• 한국세라믹학회지
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• 제42권2호
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• pp.88-93
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• 2005

아크 이온 플레이팅과 스퍼터로 구성된 하이브리드 시스템을 이용하여 다성분계 Ti-Al-Si-N 코팅막을 WC-Co 기판에 증착하였다. 증착시 Si 함량을 변화시켜 코팅막의 마모특성에 Si 함량이 미치는 영향에 대하여 조사하였다. 마모 특성을 관찰하기 위하여 Ti-Al-Si-N 코팅막이 증착된 WC-Co 원판에 3N의 하중, 0.1 m/s의 속도로 볼 온 디스크(ball-on-disk) 형태의 마모시험기를 이용하여 건식 마모 실험을 하였다. 상대재로는 스틸볼과 지르코니아볼을 사용하였다. 상대재가 스틸볼의 경우 Ti-Al-Si-N 코팅막의 마찰계수가 Ti-Al-N 코팅막의 마찰계수보다 낮게 나타났다 이는 Si가 첨가되어 마모시 상대재와 코팅막 사이에 자기윤활효과(self-lubricant effect)에 의한 것으로 여겨진다. 코팅막과 스틸볼 사이에 응착 마모 거동을 보였으며, Si의 함량이 증가함에 따라 마찰계수는 감소하였다. 한편, 상대재가 지르코니아 볼의 경우 코팅막과 지르코니아 볼 사이에서 연삭마모 거동이 더 지배적이었고, Si 함량이 증가할수록 마찰계수는 증가하였다.

• 수산해양기술연구
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• 제14권2호
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• pp.69-78
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• 1978

알루미나이징강에 대하여 초기마모영역에서 rolling-sliding 마모시험을 한 결과를 요약하면 다음과 같다. 1) 2차 확산재의 내마모성이 가장 우수하고 처녀재에 비하여 저응력 레벨에서 약 18%, 고응력에서 약 40%의 마모감소를 나타낸다. 2) 2차 확산재는 피복층과 합금층 경계부근의 공공생성으로 인하여 예상보다 내마모성이 낮다. 3) 알루미나이징강의 rolling-sliding 접촉에 의한 마모파양의 형태는 spalling 이며 spalling crack은 합금속의 경계부근에서 발생한다.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2000년도 춘계학술강연 및 발표대회 강연 및 발표논문 초록집
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• pp.9-10
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• 2000

An important business-field of world-wide steel-industry is the coating of thin metal-sheets with zinc, zinc-aluminum and aluminum based materials. These products mostly go into automotive industry. in particular for the car-body. into building and construction industry as well as household appliances. Due to mass-production, the processing is done in large continuously operating plants where the mostly cold-rolled metal-strip as the substrate is handled in coils up to 40 tons unwind before and rolled up again after passing the processing plant which includes cleaning, annealing, hot-dip galvanizing / aluminizing and chemical treatment. In the liquid Zn, Zn-AI, AI-Zn and AI-Si bathes a combined action of corrosion and wear under high temperature and high stress onto the transfer components (rolls) accounts for major economic losses. Most critical here are the bearing systems of these rolls operating in the liquid system. Rolls in liquid system can not be avoided as they are needed to transfer the steel-strip into and out of the crucible. Since several years, ceramic roller bearings are tested here [1.2], however, in particular due to uncontrollable Slag-impurities within the hot bath [3], slide bearings are still expected to be of a higher potential [4]. The today's state of the art is the application of slide bearings based on Stellite\ulcorneragainst Stellite which is in general a 50-60 wt% Co-matrix with incorporated Cr- and W-carbides and other composites. Indeed Stellite is used as the bearing-material as of it's chemical properties (does not go into solution), the physical properties in particular with poor lubricating properties are not satisfying at all. To increase the Sliding behavior in the bearing system, about 0.15-0.2 wt% of lead has been added into the hot-bath in the past. Due to environmental regulations. this had to be reduced dramatically_ This together with the heavily increasing production rates expressed by increased velocity of the substrate-steel-band up to 200 m/min and increased tractate power up to 10 tons in modern plants. leads to life times of the bearings of a few up to several days only. To improve this situation. the Mechanical Alloying (MA) TeChnique [5.6.7.8] is used to prOduce advanced Stellite-based bearing materials. A lubricating phase is introduced into Stellite-powder-material by MA, the composite-powder-particles are coated by High Energy Milling (HEM) in order to produce bearing-bushes of approximately 12 kg by Sintering, Liquid Phase Sintering (LPS) and Hot Isostatic Pressing (HIP). The chemical and physical behavior of samples as well as the bearing systems in the hot galvanizing / aluminizing plant are discussed. DependenCies like lubricant material and composite, LPS-binder and composite, particle shape and PM-route with respect to achievable density. (temperature--) shock-reSistibility and corrosive-wear behavior will be described. The materials are characterized by particle size analysis (laser diffraction), scanning electron microscopy and X-ray diffraction. corrosive-wear behavior is determined using a special cylinder-in-bush apparatus (CIBA) as well as field-test in real production condition. Part I of this work describes the initial testing phase where different sample materials are produced, characterized, consolidated and tested in the CIBA under a common AI-Zn-system. The results are discussed and the material-system for the large components to be produced for the field test in real production condition is decided. Outlook: Part II of this work will describe the field test in a hot-dip-galvanizing/aluminizing plant of the mechanically alloyed bearing bushes under aluminum-rich liquid metal. Alter testing, the bushes will be characterized and obtained results with respect to wear. expected lifetime, surface roughness and infiltration will be discussed. Part III of this project will describe a second initial testing phase where the won results of part 1+11 will be transferred to the AI-Si system. Part IV of this project will describe the field test in a hot-dip-aluminizing plant of the mechanically alloyed bearing bushes under aluminum liquid metal. After testing. the bushes will be characterized and obtained results with respect to wear. expected lifetime, surface roughness and infiltration will be discussed.