• Title/Summary/Keyword: cold Processing

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Study on the Cold Forging Process of Aluminum Pipe Yoke using Sliding Die for Reducing Friction (마찰저감을 위한 슬라이딩 금형을 적용한 알루미늄 파이프 요크 냉간 단조공정에 관한 연구)

  • S. M. Lee;I. K. Lee;S. Y. Lee;;J. W. Park;W. S. Hwang;Y. H. Moon;S. K. Lee
    • Transactions of Materials Processing
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    • v.32 no.1
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    • pp.5-11
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    • 2023
  • The aim of this study is to manufacture an aluminum pipe yoke of automotive steering system for lightweight. In a multistage cold forging process for aluminum pipe yoke, the surface defects frequently occur due to excessive deformation or friction during extrusion process for forming hollow pipe part. It is import to reduce the friction between the material and the forging die. This study investigated a multistage forging process with sliding die to reduce friction for aluminum pipe yoke. After evaluating by FE analysis, the forging experiment with the sliding die was carried out. As a result, it was possible to manufacture a sound aluminum pipe yoke.

Study on the Deacidification of Wine Made from Campbell Early (Campbell Early를 이용하여 만든 포도주의 산도 감소에 관한 연구)

  • Lee, Ju-Kyung;Kim, Jae-Sik
    • Korean Journal of Food Science and Technology
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    • v.38 no.3
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    • pp.408-413
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    • 2006
  • The domestic grape cultivar Campbell Early has high levels of both malic acid and tartaric acid. Therefore, the processing of wine made from Campbell Early must include decreasing the acidity. Six different methods were tested for reducing excess acidity: traditional vinification, precipitation, cold stabilization, malolactic fermentation (MLF), carbonic maceration and cold fermentation. Wines had higher pH values and lower total acidity than control after all the processing methods except cold stabilization. With regard to the measured organic acid content, the control contained 2,927 ppm tartaric acid, 2,421 ppm malic acid and 486 ppm lactic acid, but the precipitated wine contained 2,346 ppm tartaric acid. The MLF wine contained 828 ppm malic acid and 2,394 ppm lactic acid. Wine after carbonic maceration contained 792 ppm malic acid and cold fermentation decreased the organic acid contents in general. Sensory analysis showed that the carbonic maceration and precipitation methods resulted in wines that were excellent in color, flavor, taste and overall preference.

A Study on the Competition Structure and Effective Factors for Management Performance of the Fisheries Cold-Storage Warehouse Industry (수산물 냉동냉장창고업의 경쟁구조와 경영성과 영향요인에 관한 연구)

  • 장영수;장수호;장홍석
    • The Journal of Fisheries Business Administration
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    • v.30 no.1
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    • pp.119-147
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    • 1999
  • This article is subject to the rationalization of the cold-storage warehouse management, which gives the stabilization of the fishery production and the food life with respect to fisheries industry. In this point of view, the article examines to the structure of the cold-storage warehouse industry from the perspective of the industrial organization. To put it concretely, the article intends to apprehend the state of the structure of the industry and analyze the cold-storage warehouse's management activities. In addition, I try to find know the factors that affect the management performance(profitablity) of the industry through the cross-sectional correlation analysis. Finally, the conclusion of the article can be described as follows : \circled1 On the basis of the cold-storage capacity, there is the tendency that the industry concentrate in the area of Pusan(41.7%). \circled2 By formulating step of development of the industry, it is divided by six types. Type I is designed as raw material-storage warehouse for self-processing. Type IIis the raw material-storage warehouse for self-processing and storage-sale warehouse. Type III is the raw material-storage warehouse for self.distribution. Type IV is the raw material-storage warehouse for self-distribution and storage-sale warehouse. Type V is the net storage-sale warehouse. Type Ⅵ is the physical distribution center warehouse. Although each region has one representative type,6 types exist in all regions. \circled3 The competition structure of the industry has double structure on the basis of cold-storage capacity. \circled4 With respect to the management activity of the cold-storage warehouse, there is no change or even a decrease not increasing or not any change in sales from 1996 to 1997 \circled5 In order to try to induce the amount of shipper's materials, services that a cold-storage warehouse supply with its users include a custody-fee discount, a distribution-process service, a finance service, quality management service and so on. One of the best attractive services is the custody-fee service. \circled6 In the structure and management activity of the industry, the factors that affect management performance (profitablity) are a custody-fee discount, sales ability and capital structure of individual firm. Positive factor is sales ability and capital structure of individual firm. But, The custody-fee discount turns out to be a negative capital structure of individual film.

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Reduced Finite Element Simulation of Cold Forging Processes Based on the Forming Experiment (성형실험을 통한 냉간단조 공정의 단축 유한요소 시뮬레이션)

  • Lee, Chung-Ho
    • Transactions of Materials Processing
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    • v.6 no.5
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    • pp.395-399
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    • 1997
  • There exists a certain functional relation between Vickers hardness and flow stress in the strain-hardened material. Using this relation, the Vickers hardness values in the strain-hardened material can be converted into the flow stress values in good approximation. Therefore, the information about the flow stress distribution in the material can be easily acquired through a forming experiment. That makes it possible to simulate the process state for a critical moment of cold forging under the given boundary conditions very quickly without calculating the foregoing history of the actual deformation from the beginning.

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The Rotary Powder Compacting Process by the Cold Rotary Forging (회전성형법에서 Rotary Powder Compacting 공정에 관한 특성 연구)

  • 윤덕재;임성주;최석우;나경환
    • Transactions of Materials Processing
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    • v.6 no.3
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    • pp.227-232
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    • 1997
  • This study is concerned with the rotary powder compacting by the cold rotary forging process. An experiment has been carried out using the rotary powder forging press(500kN) which was designed and constructed in the authors' laboratory. The detailed comparisons of several mechanical test by rotary powder forging and rotary powder compacting process are given. It is found that the highly densified P/M parts can be obtained and this process is very effective for improving quality of the powder products.

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Finite Element Analysis of a Cold Forging Process Having a Floating Die (부유금형을 가진 냉간단조 공정의 유한요소해석)

  • 류찬호;전만수
    • Transactions of Materials Processing
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    • v.9 no.2
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    • pp.159-164
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    • 2000
  • In this paper, a computer simulation technique for the forging process having a floating die is presented. The penalty rigid-plastic finite element method is employed together with an iteratively force-balancing method, in which the convergence is achieved when the floating die part is in force equilibrium within the user-specified tolerance. The force balance is controled by adjusting the velocity of the floating die in an automatic manner. An application example of a three-stage cold forging process is given.

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Effects of Various Thawing Methods on the Quality Characteristics of Frozen Beef

  • Kim, Young Boong;Jeong, Ji Yun;Ku, Su Kyung;Kim, Eun Mi;Park, Kee Jae;Jang, Aera
    • Food Science of Animal Resources
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    • v.33 no.6
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    • pp.723-729
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    • 2013
  • In this study, the quality characteristics due to the influence of various thawing methods on electro-magnetic and air blast frozen beef were examined. The loin and round of second grade Hanwoo were sliced into 5-7 cm thickness and packed with aerobic packaging. The packaged beef samples, which were frozen by air blast freezing at $-45^{\circ}C$ and electro-magnetic freezing at $-55^{\circ}C$, were thawed by 4 thawing methods with refrigeration ($4{\pm}1^{\circ}C$), room temperature (RT, $25^{\circ}C$), cold water ($15^{\circ}C$), and microwave (2450 MHz). These samples were thawed to the point, which were core temperature reached $0^{\circ}C$. Analyses were carried out to determine drip and cooking loss, water holding capacity (WHC), moisture contents and sensory evaluation. Frozen beef thawed by microwave indicated a lower drip loss (0.66-2.01%) than the other thawing methods (0.80-2.50%). Cooking loss after electro-magnetic freezing indicated 52.0% by microwave thawing for round compared with 41.8% by refrigeration, 50.1% by RT, and 50.8% by cold water. WHC thawing by microwave with electro-magnetic freezing didn't showed any difference depending on the thawing methods, while moisture contents was higher thawing by microwave with electro-magnetic freezing than refrigeration (71.9%), RT (75.0%), and cold water (74.9%) for round. The texture of sensory evaluation for round thawed by microwave result was the highest than refrigeration (4.7 point), RT (6.4 point) and cold water (6.6 point), while sensory evaluation was no significant difference. Therefore, it was shown that microwave thawing is an appropriate way to reduce the deterioration of meat quality due to freezing.

Development of Hot and Cold Forging Process for Manufacturing a Hub of Dual Clutch Transmission (변속기용 허브 부품 제조를 위한 열간 및 냉간 복합단조 공정 개발)

  • Jo, A.R.;Jeong, M.S.;Lee, S.K.;Cho, Y.J.;Hwang, S.K.
    • Transactions of Materials Processing
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    • v.28 no.6
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    • pp.321-327
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    • 2019
  • In this study, a hot and cold forging process was investigated to produce a complex-shaped hub of dual clutch transmission with low material loss and high productivity. The process was designed by the commercial finite element (FE) analysis program, DEFORM-2D (hot forging) and 3D (cold forging). And, the material flow and ductile fracture characteristics were studied to check the surface crack initiation of the specimen. The simulation results indicated that the proposed process could manufacture the complex-shaped hub with no surface crack and high-efficiency compared to the conventional machining process. For verification the numerical results, the hub of the SCM440 was fabricated by the proposed process and the mechanical properties and microstructure evolution were studied. It was demonstrated that the suggested hot and cold forging process might be useful in producing the key components of the automobile industry as a high-efficiency and environmentally friendly process.

Effect of laser shock peening and cold expansion on fatigue performance of open hole samples

  • Rubio-Gonzalez, Carlos;Gomez-Rosas, G.;Ruiz, R.;Nait, M.;Amrouche, A.
    • Structural Engineering and Mechanics
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    • v.53 no.5
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    • pp.867-880
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    • 2015
  • Mechanical fastening is still one of the main methods used for joining components. Different techniques have been applied to reduce the effect of stress concentration of notches like fastener holes. In this work we evaluate the feasibility of combining laser shock peening (LSP) and cold expansion to improve fatigue crack initiation and propagation of open hole specimens made of 6061-T6 aluminum alloy. LSP is a new and competitive technique for strengthening metals, and like cold expansion, induces a compressive residual stress field that improves fatigue, wear and corrosion resistance. For LSP treatment, a Q-switched Nd:YAG laser with infrared radiation was used. Residual stress distribution as a function of depth was determined by the contour method. Compact tension specimens with a hole at the notch tip were subjected to LSP process and cold expansion and then tested under cyclic loading with R=0.1 generating fatigue cracks on the hole surface. Fatigue crack initiation and growth is analyzed and associated with the residual stress distribution generated by both treatments. It is observed that both methods are complementary; cold expansion increases fatigue crack initiation life, while LSP reduces fatigue crack growth rate.

Dimensional Changes and Residual Stress of Spur Gear According to the Manufacturing Processes -Comparison of Cold Forging Part with Machining Part- (스퍼기어의 제조공정에 따른 치수변화와 잔류응력에 관한 연구 -냉간 단조기어와 기계가공기어 비교-)

  • Kwon, Y.C.;Lee, J.H.;Lee, C.M.;Lee, Y.S.
    • Transactions of Materials Processing
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    • v.16 no.8
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    • pp.575-581
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    • 2007
  • The high dimensional accuracy of the cold forged part could be acquired by the accurate dimensional modification for the die, which is, the dimensional changes from the die through forged part to final part after heat treatment were considered. The experimental and FEM analysis are performed to investigate the dimensional changes from the die to final part on cold forged part, comparing with the machined gear. The dimension of forged part is compared with the die dimension at each stage, such as, machined die, cold forged part, and heat-treated-part. The elastic characteristics and thermal influences on forging stage are analyzed numerically by the $DEFORM-3D^{TM}$. The analyzed residual stress of forged part is considered into the FE-analysis for heat treatment using the $DEFORM-HT^{TM}$. The effects of residual stress affected into the dimensional changes could be investigated by the FEA. Each residual stress of gears was measured practically by laser beam type measurement.