• 제목/요약/키워드: heat/non-heat treatment

검색결과 518건 처리시간 0.022초

냉간 단조용 비조질강의 성형성과 기계적성질 연구 (The Study on the Mechanical Properties and Formability of Non-Heat-Treated Cold Forging Steels)

  • 이영선;이정환;이상용
    • 소성∙가공
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    • 제7권6호
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    • pp.530-538
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    • 1998
  • Elimination of the heat treatment process is very important in automation of metal forming since controlling heat treatment by computer has many difficulties and it has bottle neck problem. non-heat-treated steels materials which are not in need of heat treatment have been developed for cold forging. However to apply non-heat-treated steel to structural parts. it is necessary to prove reliability of mechanical properties. In order to define the reliability of mechanical properties we have investigated microstructure, hardness, the tensile strength compressive strength and tensile fatigue strength for both steels. Considering the results of high cycle fatigue test for both specimen the characteristics of non-heat-treated steel are decided on the yield strength, It has same tendency for heat-treated steel. Therefore non-heat-treated steel which has the appropriate yield strength may be applied in cold forging.

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looped wire의 하중변형도와 열처리에 의한 변화 (THE LOAD DEFLECTION RATE OF LOOPED WIRE AND ITS CHANGE BY HEAT TREATMENT)

  • 이용국
    • 대한치과교정학회지
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    • 제16권1호
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    • pp.133-144
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    • 1986
  • This study was conducted to evaluate the effects of loop formation and heat treatment upon the elastic properties of orthodontic wires. The specimens selected were .016', .018', .016x.022', and .018x.022' sized stainless steel (standard) and cobalt-chromium-nickel wires, and were divided into 7 groups as; 1. straight non-heat treated 2. U looped non-heat treated 3. L looped non-heat treated 4. Circle looped non-heat treated 5. U looped heat treated 6. L looped heat treated 7. Circle looped heat treated Heat treatment was performed in Big Jane furnace at 850' F for 3 minutes. The elastic limit and the elastic range of each specimen were determined by bending test, and load deflection rate was computed from those values. The findings were as follows; 1. The formation of loop resulted in increased load-deflection rate for both stainless steel and cobalt-chromium-nickel wires. 2. The heat treated group showed higher load-deflection rate than non-heat treated group, which was more apparent in cobalt-chromiumnickel wire than in stainless steel wire. 3. L loop had the highest load-deflection rate among 3 types of loops, followed by U loop and circle loop. 4. The specimens with greater diameter displayed the more increase in load-deflection rate by looping and heat treatment.

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수도종자의 방사선조사에 있어서 열처리의 효과 (The Effect of Heat Treatment on Biological Response and Mutation Frequency of Gamma Irradiated Rice Seeds)

  • 한창열;원종락;최광태
    • 한국작물학회지
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    • 제10권
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    • pp.45-50
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    • 1971
  • 방사선조사시 열처리의 효과를 알기 위하여 수도종자에 방사선조사시 열전후처리를 행하였던바$M_1$ 세대의 생물학적인 반응 및 $M_2$ 세대의 변이율에 대해 몇가지 결과를 얻었다. 1. 방사선선량 20kR에서 열전처리는 방사선단독조사에 비해 생물학적인 장해를 적게하고 변이율을 증가시켰다. 2. 방사선단독조사 및 조사전열처리에 비해 heat shocking으로서 열후처리하는 것은 변이율을 증가시켰다. 3. 열전처리에 의해 $M_1$ 세대의 장해가 적고 변이율이증가되는 가장 효과적인 열처리온도 및 시간은 6$0^{\circ}C$에서 30분간이었다. 4. 열처리는 방사선단독조사에 비해 mutation spectrum을 달리했다.

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열처리가 냉간가공한 stainless steel wire의 복원양상에 미치는 영향 (EFFECTS OF LOW-TEMPERATURE HEAT TREATMENT ON ELASTIC MEMORY PROCESS OF COLD WORKED STAINLESS STEEL WIRE)

  • 오정세;박수병;손우성
    • 대한치과교정학회지
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    • 제22권3호
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    • pp.647-656
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    • 1992
  • The purpose of this study was to evaluate the elastic memory process in cold worked stainless steel wire and the effect of heat treatment on it. 0.018 inch round and $0.019\times0.025$ inch rectangular wire (ORMCO stainless wire) were used in this study. Each wire type had 4 groups: non-heat treatment group, furnace heat treatment group, electric current heat treatment group, and bending after heat treatment group. Each group was consisted of 10 specimens. With the Jig, each wire was bent into v-shape uniformly, and width of two free ends of each v-shaped wire was measured by caliper (to the point of 0.1 mm correctly) at time interval of offjig, after heat treatment, 1, 2, 3, 4 hours, 1, 2, 3, 4, 5, 6 days, 1, 2, 3, 4 weeks after. The results were as follows: 1. In non-heat treatment group and bending after heat treatment group, elastic memory process was occured $60\%$ within 1 hour, and more than $90\%$ within 1 week. 2. In furnace and electric current heat treatment group, almost all elastic memory process was occured during teat treatment, and then specimen was stabilized dimensionally. 3. Magnitude of deformation by elastic memory was greater in heat treatment group than non heat treatment group and bending after heat treatment group. 4. There was no remarkable difference in deformation pattern between 0.018 inch round wire and $0.019\times0.025$ inch rectangular wire.

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플라즈마 용사코팅강재의 피로균열성장에 미치는 감화열처리의 영향 (Effect of Heat Treatment of Fatigue Crack Growth of Plasma-Sprayed Coating Steels)

  • 김귀식;현창해;김영식
    • 동력기계공학회지
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    • 제7권4호
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    • pp.55-60
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    • 2003
  • This paper is to investigate the fatigue crack growth of plasma-sprayed coating steels according to heat treatments. The experimental materials are carbon steels(substrate: S45C) with plasma-sprayed coating layers of Ni-4.5%Al and $TiO_2$. The fatigue test is conducted on compact tension specimen by a servo-hydraulic fatigue testing machine. The specimens are heat-treated at $400^{\circ}C\;and\;800^{\circ}C$, respectively. Loading condition is a constant amplitude sinusoidal wave with a frequency of 10Hz and a load ratio of 0.1. The fatigue crack growth length is automatically measured by a compliance method. In the case of non-heat treated specimens, the fatigue crack growth rates of both substrate and coating specimen are almost same. The crack growth rates of substrates and coating steels by heat treatment are larger than those of the non-heat treated one, because the ductile property increase by heat treatment. In ${\Delta}K<18MPa{\cdot}m^{1/2}$, the crack growth rates of the heat-treated specimens are slightly taster than non-heat treated one. But the both heated and non-heated one are almost same in ${\Delta}K>18MPa{\cdot}m^{1/2}$.

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가열 및 비가열 처리 액젓을 첨가하여 제조한 김치의 특성 비교 (Characteristics of Kimchi Added with Anchovy Sauce from Heat and Non-heat Treatments)

  • 강현우
    • 한국조리학회지
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    • 제19권5호
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    • pp.49-58
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    • 2013
  • 본 연구는 가열 및 비가열 처리 액젓을 첨가하여 제조한 김치의 이화학적 특성을 평가한 것으로 염도를 측정하였을 때 가열 처리 액젓 첨가 김치보다 비가열 처리 액젓 첨가 김치가 0.2% 높았고 pH는 0.09의 차이를 확인하였다. 무기질 분석에서 Ca과 Fe 함량은 비가열 처리 액젓 첨가 김치가 높았고 P, Zn, Na 함량은 가열 처리 액젓 첨가 김치가 높았다. 또한, 환원당은 비가열 처리 액젓첨가 김치에서 수치가 가장 높았고 히스타민 함량은 가열 처리 액젓 첨가 김치가 낮은 결과를 확인하였다. 총 균수와 2종류의 유산균을 실험하였을 때 총 균수는 비가열 처리 액젓을 첨가한 김치에서 많이 검출 되었지만 2종류의 유산균을 비교하였을 때는 가열 처리 액젓의 김치가 더 높았다. 본 결과는 가열 처리한 액젓을 첨가한 김치가 제조 시 대부분의 무기질 및 유산균 등에 좋은 영향을 끼친 것을 확인하였으나 향후 다양하고 명확한 분석법을 확립하여 김치 첨가제로써 액젓에 대한 최적의 결과를 도출 할 수 있을 것으로 사료된다. 본 연구를 바탕으로 향 후 식품산업 및 조리에 관련한 기초자료를 제공할 수 있을 것으로 판단된다.

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비조질 선재 제품에 대한 소개 및 최근 연구개발 동향 (Introduction of Non-Heat Treated Steel Wire Rod Developed by POSCO)

  • 이유환;김동현;이상윤;이덕락
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2009년도 추계학술대회 논문집
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    • pp.137-138
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    • 2009
  • There is a growing interest to replace the commercial steels with non-heat treated steels, which does not involve the spheroidization and quenching-tempering treatment in the steel-wire industry production. However, non-heat treated steels should satisfy high strength and good formability without performing heat treatment. Therefore, it is important to investigate optimum materials showing a good combination of strength and formability after the cold drawing process. In this presentation, non-heat treated steel wire rod produced by POSCO will be introduced and discussed on detail technical concepts.

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가열과 비가열 처리를 통한 액젓의 이화학적 특성 (Characteristics of Salt Fermented Anchovies with Heat Treatment)

  • 강현우;조영제
    • 동아시아식생활학회지
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    • 제23권1호
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    • pp.92-97
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    • 2013
  • This study was conducted to understand the quality characteristics of salt fermented anchovies with heat treatment by measuring their chemical compositions. The heat-treated and non-heat treated salt fermented anchovies contained, respectively, 63.21 and 66.51% of moisture, 2.24 and 2.12% of total nitrogen (TN), and 1,537 and 1,520 mg/100 g of amino nitrogen (AN). In addition, heat-treated and non-heat-treated salt fermented anchovies contained 127 and 134 mg/100 g of volatile basic nitrogen (VBN), respectively. Moreover, measured the microbial level of heat-treated and non-heat-treated salt fermented anchovies was $2.58{\times}10^4$ and $3.61{\times}10^2$ CFU/mL, respectively. Also, the heat-treated and non-heat-treated salt fermented anchovies 3.65 and 0.30 units of protease activities, respectively. The total free amino acid contents in heat-treated and non-heat-treated salt fermented anchovies was 4,964 and 6,638 mg/100 g, respectively. The major free amino acid were glutamic acid, leucine, lysine, alanine, valine, isoleucine. Our results provide the characteristics of salt fermented anchovies and encourage their application for the food industry and cooking.

냉간 가공시 조질 및 비조질강의 성형성과 기계적성질의 비교 연구 (The Study on Mechanical Properties and Formability of Non-Heat-Treated and Heat-Treated Cold Forging Materials)

  • 이영선;이정환;이상용;강종훈;김주현
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 1998년도 춘계학술대회논문집
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    • pp.224-230
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    • 1998
  • Non-heat-treated type material has been investigated for formability compared to heat-treated material. It is very important in automation of metal forming, since it has difficulties of controlling heat treating system by the computer and has bottle neck problem related with heat treatment. In this paper, we have concerned about mechanical properties of non-heat-treated material after the forging. To compare the characteristics between heat-treated material and non-heat-treated material, tensile, compression and fatigue test has been performed. Considering results of mechanical properites of non-heat-treated material, it can replace heat-treated material. Therefore non-heat-treated material may be applied to cold forging.

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