• 제목/요약/키워드: hot deformation

검색결과 460건 처리시간 0.03초

급냉응고 및 열간가공된 Al-Zr계 합금의 석출거동 (Precipitation Behaviors of Rapidly Solidified and Hot Worked Al-Zr Base Alloys)

  • 박원욱
    • 한국주조공학회지
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    • 제15권2호
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    • pp.194-200
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    • 1995
  • Rapidly Solidified (RS) Al-Zr base splats with various alloy contents were prepared by atomization-splat quenching method to understand the continuous and discontinuous precipitation in the aged alloys. And the RS alloys were consolidated by hot extrusion and swaging to analyze the effect of plastic deformation on the precipitation behavior. Discontinuous precipitation dominated at relatively low temperature in the Al-Zr alloy, whereas both V additions to Al-Zr alloys and hot metal working appeared to suppress the discontinuous precipitation. As continuous precipitation is favored in the grain interiors, the driving force for discontinuous precipitation become to disappear with a further process.

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보론강을 이용한 CTBA의 후열처리 공정 실험 및 해석 (Try out and Analytical Researches on Quenching Process of Coupled Torsion Beam Axle using Boron Steel Tube)

  • 윤석진;박종규;김양수;서창희;이경훈;김헌영
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2009년도 추계학술대회 논문집
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    • pp.181-184
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    • 2009
  • The hot press farming process, which is the press hardening of steel parts using cold dies, can utilize both ease of shaping and high strength due to the hardening effect of rapid quenching during the pressing. In this study, a thermo-elastoplastic analysis of the hot press forming process using the finite element method was performed in order to investigate the deformation behavior and temperature history during the process and the mechanical properties of the pressed parts.

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유한요소법을 이용한 Inconel 718의 열간단조공정시 동적재결정거동 예측 (Prediction of the Behavior of dynamic Recrystallization in Inconel 718 during Hot Forging using Finite Element Method)

  • 최민식;강범수;염종택;박노광
    • 소성∙가공
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    • 제7권3호
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    • pp.197-206
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    • 1998
  • This paper presents the prediction of dynamic recrystallization behavior during hot forging of Inconel 718. Another experiment of pancake forging was also carried out to examine the recrystallization ration dynamically recrystallizaed grain size, and grain growth in the forging. In experiments cylindrical billets were forged by two operations with variations of forging temperature, reduction ration of deformation. and preheating process at each forging step. Also the finite element program, developed here for the prediction using the metallurgical models was used for the analysis of to Inconel 718 upsetting and the results were compared with experimental ones.

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열연화를 고려한 금형마멸모델에 관한 연구(II) -마멸모델의 적용 (A Study on Die Wear Model considering Thermal Softening(II) -Application of Suggested Wear Model)

  • 강종훈;박인우;제진수;강성수
    • 소성∙가공
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    • 제7권3호
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    • pp.282-290
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    • 1998
  • In bulk metal forming processes prediction of tool life is very important for saving production cost and achieving good material properties. Generally the service life of tools in metal forming process is limited to a large extent by wear, fracture and plastic deformation of tools. In case of hot and warm forging processes tool life depends on wear over 70%. In this study finite element analyses are con-ducted to warm and hot forging by adopting suggested wear model. By comparison of simulation and eal profile of die suggested wear model. By comparison of simulation and real profile of die suggested model is verified.

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격자압축법을 이용한 3차원 단조공정해석 (3-D Analysis of Hot Forging Processes using the Mesh Compression Method)

  • 홍진태;양동열
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 춘계학술대회논문집C
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    • pp.492-497
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    • 2001
  • In the finite element analysis of metal forming processes using general Lagrangian formulation, element nodes in the mesh move and elements are distorted as the material is deformed. The excessive degeneracy of mesh interrupts finite element analysis and thus increases the error of plastic deformation energy. In this study, a remeshing scheme using so-called mesh compression method is proposed to effectively analyze the flash which is generated usually in hot forging processes. In order to verify the effectiveness of the method, several examples are tested in two-dimensional and three-dimensional problems.

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Dynamic Rheological Invest igation of Hot Pepper-soybean Paste Mixed with Acetylated Starch: Effect of Storage Time and Temperature

  • Yoo, Byoung-Seung
    • Food Science and Biotechnology
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    • 제17권5호
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    • pp.1119-1121
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    • 2008
  • The effects of storage time (0, 1, and 2 month) and temperature (5, 15, and $25^{\circ}C$) on the dynamic rheological properties of hot pepper-soybean paste (HPSP) mixed with acetylated starches (AS) were studied by small-deformation oscillatory measurements. Dynamic moduli (G', G", and $\eta^*$) values of HPSP-AS mixtures increased with an increase in storage time and also decreased with increasing storage temperature. However, dynamic moduli values of the control (no added AS) were independent on storage time and temperature. Tan $\delta$ values (ratio of G"/G') in all HPSP samples did not change much with an increase in storage time and temperature. After 2 months of storage, the dynamic moduli of the HPSP-AS mixture samples were much lower than those of the control, indicating that the addition of AS can inhibit the retrogradation that developed over a long period of storage. Structural and rheological properties of HPSP samples seem to be stabilized by the presence of AS.