• 제목/요약/키워드: Bake

검색결과 139건 처리시간 0.028초

일괄 풀림처리된 강판의 예비 변형정도에 따른 소열경화 특성 (Bake hardenability of batch annealed steel sheets with prestrain)

  • 허훈;황필상
    • 오토저널
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    • 제12권1호
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    • pp.40-48
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    • 1990
  • Bake hardenability of batch annealed steel sheets is investigated in connection with the amount of tensile deformation and the bake hardening condition. This study associates with the method for producing bake hardening materials by means of batch annealing process and for measuring bake hardenability which is not yet fully established. The experimental result demonstrates the relationship between strain distribution and bake hardening behavior in various bake hardening conditions, which provides an essential information for automobile design and related sheet metal forming in a press shop. The result also shows the bake hardenability of the tested material increases as the baking temperature is increased from 150.deg. C. The result assures the bake hardening materials can guarantee reasonably high strength as well as good uniformity in yield strength for the automobile body by sheet metal forming process.

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과학위성1호 비행모델 Bake-Out 시험결과 분석

  • 조혁진;서희준;이상훈;조창래;문귀원;최석원
    • 항공우주기술
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    • 제2권2호
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    • pp.45-49
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    • 2003
  • 한국항공우주연구원 위성시험동에 설치된 Bake-Out 챔버를 통하여 과학위성 1호 비행모델(STSAT-1FM)에 대한 Bake-Out 시험이 수행되었다. 본 시험은 시험 후에 장착될 FIMS라는 광학장비에 영향을 미칠 Outgassing Rate의 측정 및 고온에서의 Bake-Out을 통한 오염물질 제거에 목적을 둔 시험으로 총 10일여 동안 시험이 수행되었다. Honeycomb Panel 및 Harness에 대한 시험(Batch 1), 조립된 비행모델에 대한 Bake-Out(batch 2), 그리고 part별로 펼쳐진 상태로의 Bake-Out 시험(Batch 3), 총 세 번의 시험으로 이루어졌다. 각각의 시험에 대하여 TQCM(Thermoelectric Quartz Crystal Microbalance) 및 RGA(Residual Gas Analyzer)를 통하여 Outgassing 물질에 대한 정량적, 정성적 측정 및 분석이 이루어졌다.

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자동차용 소부경화형(BH) 강의 고주기 피로 특성에 미치는 미세 황화물의 영향 (Effect of Fine Copper Sulfides on the High Cycle Fatigue Properties of Bake Hardening Steels for Automotive)

  • 강성규;김진용;최일동;이승복;홍문희
    • 대한금속재료학회지
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    • 제49권3호
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    • pp.203-210
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    • 2011
  • Bake hardening steels have to resist strain aging to prevent the yield strength increment and stretcher strain during press process and to enhance the bake hardenability during baking process after painting. The bake hardening steels need to control the solute carbon and the solute nitrogen to improve the bake hardenability. Ti and/or Nb alloying for nitride and carbide precipitation and low carbon content below 0.003% are used to solve strain aging and formability problem for automotive materials. However, in the present study, the effect of micro-precipitation of copper sulfide on the bake hardenability and fatigue properties of extremely low carbon steel has been investigated. The bake hardenability of Cu-alloyed bake hardening (Cu-BH) steel was slightly higher (5 MPa) than that of Nb-alloyed bake hardening (Nb-BH) steel, but the fatigue limit of Cu-BH steel was far higher (45 MPa) than that of Nb-BH steel. All samples showed the ductile fracture behavior and some samples revealed distinct fatigue stages, such as crack initiation, stable crack growth and unstable crack growth.

시판 소금의 중금속 함량과 천일염의 온도변화에 따른 중금속 함량 (Heavy Metal Contents of Marketing Salts and Bay Salts by Heating)

  • 홍광택;이종영;장봉기
    • 환경위생공학
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    • 제11권3호
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    • pp.79-84
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    • 1996
  • In order to determine the content of heavy metal in common salts, 35 bay salt samples, 7 refined salt samples, 7 fine salt samples, 5 bake salt samples and 5 bamboo bake salt samples were collected from old market in major cities. Heating bay salt 35 samples, it made heating bay salt of $500^{\circ}C$, /TEX>(34 samples), heating bay salt of $1000^{\circ}C$(35 samples). These were analysed for contents of lead(Pb), cadmium(Cd), iron(Fe) and zinc(Zn) by atomic absorption spectrophotometer. The results were as follows : Mean content of lead in bay salts was $0.124{\pm}0.035ppm$ refined salt was $0.130{\pm}0.019ppm$, fine salt was $0.073{\pm}0.036ppm$ bake salt was $0.097{\pm}0.023ppm$, bamboo bake salt was $0.117{\pm}0.020ppm$, heating bay salt was $0.063{\pm} 0.021ppm$ in $500^{\circ}C$, heating bay salt was $0.063{\pm}0.039ppm$ in $1000^{\circ}C$. And bay salt refined salt bamboo bake salt were not significant one another. Mean content of cadmium in bay salts was $0.031{\pm}0.008ppm$ refined salt was $0.032{\pm}0.003ppm$, fine salt was $0.037{\pm}0.005ppm$, bake salt was $0.169{\pm}0.117ppm$ bamboo bake salt was $0.079{\pm}0.052ppm$, heating bay salt of $500^{\circ}C$ was $0.030{\pm}0.029ppm$ heating bay salt of $1000^{\circ}C$ was $0.017{\pm}0.013ppm$. And bay salt refined salt, fine salt were not significant one another. Mean content of iron in bay salts was $1.025{\pm}0, 634ppm$, refined salt was $0.359{\pm}0.163ppm$ fine salt was $0.267{\pm}0.068ppm$, bake salt was $2.929{\pm}1.963ppm$, bamboo bake salt was $5.378{\pm}3.676ppm$, heating bay salt of $500^{\circ}C$ was $0.847{\pm}0.315ppm$ heating bay salt of $1000^{\circ}C$ was $0.991{\pm}0.868ppm$. And bay salt refined salt, fine salt, bake salt, bamboo bake salt were significant one another(p<0, 01). Mean content of zinc in bay salts was $0.253{\pm}0.154ppm$, refined salt was $0.263{\pm}0.091ppm$ fine salt was $0.187{\pm}0.015ppm$, bake salt was $0.166{\pm}0.034ppm$, bamboo bake salt was $0.282{\pm}0.064ppm$, heating bay salt of $500^{\circ}C$ was $0.253{\pm}0.085ppm$, heating bay salt of $1000^{\circ} C$ was $0.242{\pm}0.179ppm$. And bay salt refined salt fine salt, bake salt, bamboo bake salt were not significant one another.

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Bake Out에 의한 실내오염물질 저감에 관한 연구 (A Study on the Reducing Ratio of VOCs and Formaldehyde by Bake Out)

  • 조현;박용승;유복희;홍천화
    • 한국주거학회:학술대회논문집
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    • 한국주거학회 2004년도 추계학술대회 논문집
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    • pp.319-322
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    • 2004
  • The purpose of this study is to evaluate the reduction effect of bake out on the concentration of indoor air pollutants by measuring the concentration of indoor pollutants(VOCs, HCHO) after the bake out. As a result of the study, bake out was considerably effective in reducing the concentration o( indoor air pollutants, showing relatively high reduction ratio around 40${\sim}$56%. However, continuous attention and control after the bake out is required for the prevention of the rise of the concentration by subsequent emission.

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2상 조직을 갖는 소부경화강의 항복 거동과 변형 시효 특성 (Yielding Behavior and Strain Aging Properties of Bake Hardening Steel with Dual-Phase Microstructure)

  • 이승완;이상인;황병철
    • 한국재료학회지
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    • 제30권6호
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    • pp.315-320
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    • 2020
  • This study deals with the yielding behavior and strain aging properties of three bake hardening steels with dual-phase microstructure, fabricated by varying the annealing temperature. Bake hardening and aging tests are performed to examine the correlation of martensite volume fraction with yielding behavior and strain aging properties of the bake hardening steels with dual-phase microstructure. The volume fraction of martensite increases with increasing annealing temperature. Room-temperature tensile test results show that the yielding behavior changes from discontinuous-type to continuous-type with increasing volume fraction of martensite due to higher mobile dislocation density. According to the bake hardening and aging tests, the specimen with the highest fraction of martensite exhibited high bake hardening with low aging index because solute carbon atoms in ferrite and martensite effectively diffuse to dislocations during the bake hardening test, while in the aging test they diffuse at only ferrite due to lower aging temperature.

Formaldehyde Emissions and Moisture Content Change of Wood Composites during Bake-out

  • Lee, Young-Kyu;Kim, Hyun-Joong
    • Journal of the Korean Wood Science and Technology
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    • 제40권2호
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    • pp.101-109
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    • 2012
  • Wood composites are a hygroscopic material and have ability to exchange its moisture content with air. This study investigated the formaldehyde emission and moisture content change of four wood composites (particleboard (PB), medium density fiberboard (MDF), high density fiberboard (HDF), laminated HDF (L-HDF)) as a function of bake-out temperature and time. The composites were baked out for 1, 3, 5, 7, 10, 14, 21, and 28 days at temperatures of $20{\pm}2$, $35{\pm}2$, and $50{\pm}2^{\circ}C$ in a dry oven. The moisture content change was used to determine the emission bake-out of the composites. Best bake-out time results were obtained with after 7 days all composites. Formaldehyde emission values of composites decreased with decreasing moisture content for both temperatures. The formaldehyde emission results of bake-out temperature 35 and $50^{\circ}C$ showed a similar tendency.

저온 Si계 에피 성장기술에서 실험계획법에 의한 in-situ H$_2$ bake 및 GeH$_4$ clean 공정 최적화 (The process optimization of in-situ H$_2$ bake and GeH$_4$ clean in low temperature Si epitaxy using design of experiment)

  • 이경수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1994년도 추계학술대회 논문집
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    • pp.54-58
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    • 1994
  • H$_2$ bake and GeH$_4$ clean are used as a in-situ pre-clean method in low temperature Si based epitaxial growth technology using rapid thermal processing chemical vapor deposition (RTPCVD). In this paper, the H$_2$ bake and GeH$_4$ clean processes are optimized for low surface defect density using Taguchi method. In H$_2$ bake process, the epitaxial growth temperature affects dominantly on the surface defect density, and the next affecting factors are H$_2$ bake temperature and rinse time in de-ionised water. In GeH$_4$ clean process, GeH$_4$ clean temperature affects most strongly on the surface defect density, and the minor factor is GeH$_4$flow rate. The optimum process conditions predicted fly Taguchi method agree well with tile experimental data in both in-situ clean processes.

Bake-Out에 의한 신축 아파트의 실내 오염물질농도 저감효과 평가 (The Impact of Bake-Out Method on the Reduction of Pollutant Concentration in New Apartments)

  • 방승기;박병윤
    • 설비공학논문집
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    • 제18권4호
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    • pp.335-343
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    • 2006
  • Indoor air pollution has been significantly aggravated due to hazardous pollutants emitted from petrochemical finishing materials in new apartments. Pollutants emitted into indoor environment have significant effects on the health of occupants, causing undesirable symptoms related to sick building syndrome such as headache, dizziness, difficulty in concentration, etc. Therefore, this paper attempted to investigate the reduction effect of bake out on VOCs emission in new apartments. Experiments were carried out in three households, one of which was naturally ventilated. The naturally ventilated showed the lowest indoor pollutant concentration and also showed the highest reduction rate by the use of bake out. The most desirable result was observed when the household was naturally ventilated after bake out. More detailed experiments are expected to be carried out afterwards on the prediction of reduction rate of each pollutant.

Effect of Pre-Aging Conditions on Bake-Hardening Response of Al-0.4 wt%Mg-1.2 wt%Si-0.1 wt%Mn Alloy Sheets

  • Lee, Kwang-jin;Woo, Kee-do
    • 대한금속재료학회지
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    • 제49권6호
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    • pp.448-453
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    • 2011
  • Pre-aging heat treatment after solution heat treatment (SHT) of Al-0.4 wt%Mg-1.2 wt%Si-0.1 wt%Mn alloy sheets for auto-bodies was carried out to investigate the effect of pre-aging and its conditions on the bake-hardening response. Mechanical properties were evaluated by a tensile and Vickers hardness test. Microstructural observation was also performed using a transmission electron microscope (TEM). It was revealed that pre-aging treatments play a great role in the bake-hardening response. In addition, it was found that the sphere-shaped nanosized clusters that can directly transit to the needle-shaped ${\beta}$" phase during the paint-bake process, not being dissolved into the matrix, are formed at 343 K. The result, reveals that the dominant factor of the bake-hardening response is the pre-aging temperature rather than the pre-aging time.