• 제목/요약/키워드: 온간

검색결과 166건 처리시간 0.022초

합금화 용융 아연 도금강판의 온간 디프드로잉 성형성에 관한 연구 (A Study on the Warm Beep Drawabilities of Galvannealed Steel Sheet)

  • 장성호;최치수;최이천;서대교
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2000년도 추계학술대회 논문집
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    • pp.168-173
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    • 2000
  • The limiting drawing ratio (LDR) under uniform heating of blanks was measured at the various temperature ranges between 25 and $250^{\circ}C$ by using two different blank shapes, square and circular blanks, and six different blank sizes with the drawing ratios(DR) of 2.4 to 2.9. The galvannealed steel sheet (SCP3CM 60/60) of 0.7mm thickness was used. The LDR at warm forming condition reached 1.2 times of that at room temperature, and the maximum drawing depth reached 1.9 times. The higher temperature was adopted, the more stable and uniform thickness strain distribution was observed.

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온간단조 윤활제의 윤활 및 냉각특성 (Lubrication and Cooling Characteristics of Warm Forging Lubricants)

  • 강종훈;고병호;제진수;강성수
    • 소성∙가공
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    • 제14권7호
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    • pp.619-623
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    • 2005
  • Lubrication and cooling characteristics are the most important factors of elevated temperature forging lubricants. Usually adopted lubricants in warm forging processes are graphite, synthetic and emulsion lubricants. Most widely and effectively applied lubricants are graphite lubricants, but these have a lot of problems like tool corrosion and dusty environment. In this research, boronite lubricant is considered, because it is able to substitute for graphite. Hot ring compression test, cooling test and mass production test are performed to check the validity of new lubrication pigment.

알루미늄 튜브 온간 하이드로포밍 성형성에 관한 연구 (Studies on the Warm Hydroformability of Aluminum Tubes)

  • 김봉준;류종수;김대현;김동우;문영훈
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2004년도 춘계학술대회 논문집
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    • pp.198-201
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    • 2004
  • Aluminum alloys have high potential for weight reduction in automotive and other applications. But aluminum alloys have relatively low tubular hydroformability which can be enhanced by conducting the hydroforming at elevated temperatures. Hot working processes are commonly used in bulk forming such as forging and rolling, but still is rare in sheet metal forming like hydroforming. In this study hydroforming test at elevated temperatures is performed by special designed induction heating system to investigate the hydroformability of aluminum alloys. The high temperature formability characteristrics are obtained by 1?fitting forming test and circular bulging test and the effects of the process parameters such as feeding amount, internal pressure and temperatures on the tubular forming limits are mainly investigated.

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Mg 합금 온간 판재 성형시 공정 변수의 영향에 관한 연구 (An Effect on the Process Parameter of Mg Alloy at Warm Sheet Forming)

  • 이영선;권용남;김민철;최상운;이정환
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2006년도 춘계학술대회 논문집
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    • pp.43-47
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    • 2006
  • Since the sheet metal forming of Mg alloy is performing at elevated temperature, the effect of process conditions related with the forming temperature is very important factor. Therefore, the investigation for process variables is necessary to design the tools and process conditions. In this study, the effects of process variables were studied by the experimental and FE analysis using the square cup deep drawing. The temperature, forming speed, and lubricant condition were investigated. When forming temperature was $250^{\circ}C$, speed forming was low, and teflon sheet was used as lubricant, the formed parts were good without defects.

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Cu기 비정질 합금의 과냉각 액상구간에서 온간 압연시 Roll 온도의 영향 (Evolution of temperature gradients during rolling of $Cu_{54}Ni_6Zr_{22}Ti_{18}$ bulk metallic glass in the super cooled liquid region)

  • 박은수;이주호;김휘준;배정찬;허무영
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2006년도 춘계학술대회 논문집
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    • pp.409-412
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    • 2006
  • Bulk metallic glass (BMG) strips of $Cu_{54}Ni_6Zr_{22}Ti_{18}$ were produced by warm rolling of the amorphous powder canned with copper. Controlling of temperatures of the rolled sample and rolls was essential for the successive rolling process. Because improper controlling of the sample temperature gave rise to the crystallization of BMG loading to the catastrophic fracture of BMG strips, the temperature of rolls should be properly controlled for achieving successful powder rolling of BMG. The variations of the strain state and temperature in the roll gap was simulated by the finite element method(FEM) using various roll temperatures.

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마그네슘 합금 판재의 온간 딥드로잉 공정의 성형해석 (Forming Analysis for Warm Deep Drawing Process of Magnesium Alloy Sheet)

  • 이명한;김헌영;김형종;김흥규;오수익
    • 소성∙가공
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    • 제16권5호통권95호
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    • pp.401-405
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    • 2007
  • Due to the low densities and high specific strength and stiffness, magnesium alloy sheets are very attractive lightweight materials for automotive and electrical products. However, the magnesium alloy sheets should be usually formed at elevated temperature because of their poor formability at room temperature. For the use of the magnesium alloy sheets for an industrial, their mechanical properties at elevated temperature and appropriate forming process conditions have to be developed. In this study, non-isothermal simulation of a square cup drawing of magnesium alloy sheets have been conducted to evaluate a proper forming process conditions such as the tool temperature, the tool shoulder radius, friction between the blank and the tools. According to this study, appropriate forming process conditions of square cup drawing at elevated temperature from magnesium alloy sheets are suggested.

AZ31B 마그네슘 합금판재의 온간 성형한계도 및 스프링백 특성 시험 (Experiments for Forming Limit Diagram and Springback Characteristics of AZ31B Magnesium Alloy Sheet at Elevated Temperature)

  • 김헌영;최선철;이한수;김형종;이경택
    • 소성∙가공
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    • 제16권5호통권95호
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    • pp.364-369
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    • 2007
  • The effect of temperature on the forming limit diagram was investigated for AZ31B magnesium alloy sheet through the limit dome height test in the range from room temperature to $300^{\circ}C$. The formability of AZ31B sheet was improved significantly according to the increasing temperature. Also we studied the springback characteristics through the 2D draw bending test with different blank holding forces at elevated temperatures. Springback quantity was considerably reduced as temperature went up. The blank holding force in the range used, however, had little influence on springback. Experimental results obtained in this study may provide a material database for AZ31B sheet.

마그네슘 판재 온간 성형의 파단 예측 모델 비교 연구 (A Comparative Study of Failure Criteria for Magnesium Alloy Sheet under Warm Press Forming Condition)

  • 김흥규;김종덕;허영무;김우진
    • 소성∙가공
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    • 제21권2호
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    • pp.113-118
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    • 2012
  • Magnesium sheet alloys possess limited plastic formability at room temperature but their formability is substantially improved at elevated temperatures and optimum strain rates. In the present paper, three different types of failure criteria, namely, strain-based, stress-based, and work-based criteria, are compared for their applicability to warm press forming of magnesium sheet alloys. Warm deep-drawing experiments were conducted on AZ31 alloy sheet, and the results were used to assess the strength and weakness of the failure criteria.

국소 가열방법을 이용한 2단게 축대칭 디프 드로잉 공정의 해석 및 설계

  • 이동우;송인섭;양동열
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1992년도 춘계학술대회 논문집
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    • pp.104-108
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    • 1992
  • 국소가열 가공방법은 종래 사용 되어온 온간,열간 가공의 경우와는 달리 프레스 성형의 응력조건 또는 양긱,열(온도)에 의한 재료 성질의변화 등을 고려하여, 가공하는 박판의 필요 부분을 선택적으로가열, 냉각 또는 두가지를 조합하여 처리하는 것이다. 온도 구배의 영향이 박판 성형의 공정에 많은 영향을 줌에도 불구하고 종래의 박판 성형가공은 주로 열을 고려하지않은 성형해석이 대부분이었고 열을 고려 하였다라도 대 부분이 실험에의존 한 방법이었다. 그러나 실제의 공정 설계에서 실험만을 통한 공정 변수의규명은 많은 노 력과 시간을 필요로 하기 때문에 컴퓨터를 통한 시뮬레이션의 필요성이 대두 되었다. 본 연구는 박판 축대칭 온도 구배와, 변형해석을 유한 요소적 방법을 통해 행하고 이를 실제 공정 설계에 적용할 수있도록 도움을 주고자 하는 데에 있다.

크롬 코팅 처리된 금형에서 박판의 온간 딥드로잉 성형성에 관한 연구 (A Study on the Warm Deep Drawing Ability of Sheets on Cr-Coating Die)

  • 공경환
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 1999년도 춘계학술대회논문집
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    • pp.63-70
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    • 1999
  • Some deep drawing characteristics to the elevated temperatures were investigated for the SCP1 steel sheets by using the Cr-coated die. For this investigations six steps of temperature ranges from room temperature to 25$0^{\circ}C$ and six kinds of drawing ratio from 2.4 to 2.9 were adopted. As a result the limiting drawing ration maximum drawing force and the maximum drawing depth were sensitively affected by the elevated temperatures and the more stable thickness strain distribution was observed to the elevated temperatures, Some experimental results were compared with analytical results using the DYNA-3D code.

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