• Title/Summary/Keyword: Finishing Mill

Search Result 112, Processing Time 0.031 seconds

A Study on the roll gap set-up at top-end in plate rolling using finite element analysis (유한요소해석을 이용한 후판 압연공정의 선단부 롤갭 설정연구)

  • Yim, H.S.;Jang, J.H.;Choi, M.K.;Seo, J.H.;Moon, Y.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 2009.05a
    • /
    • pp.252-255
    • /
    • 2009
  • The roll gap set-up in the finishing mill is one of the most important technologies in the hot plate rolling process. As the target thickness can be obtained by the correct set-up of the roll gap, improving the roll gap set-up technology is very critical for plate thickness accuracy. The main cause of thickness variation in hot plate mills is the non-uniform temperature distribution along the length of the slab. The objective of this study is to adjust the roll gap set-up for the thickness accuracy of plate in hot rolling process considering top-end temperature drop. Therefore this study has concentrated on determining the correct amounts of roll gap to compensate thickness variation due to top-end temperature drop. The off-line simulation of compensated roil gap significantly decreases top-end thickness variation.

  • PDF

Simulation of H-beam rolling process using FEM (FEM을 이용한 H형강 압연공정 해석)

  • Park, C.S.;Kim, J.M.;Woo, K.M.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 2008.05a
    • /
    • pp.419-422
    • /
    • 2008
  • It is most important to design the roll pass in shape rolling process. However, roll pass design has been accomplished by experience and intuition of a skilled engineer up to now. And it has being produced throughout a lot of trial and error. Thus, in this study, we tried to analysis the rolling process of H-beam by using FEM program for the quantitative evaluation of the plastic deformation. It could be predicted that rolling load, torque, shape of cross section and distribution of effective strain each pass by the analysis of rolling from break down mill(2 Hi rolling) to finishing rolling(Universal rolling) considering the heat transfer.

  • PDF

Effects of the Low-Crude Protein and Lysine (Low CP/lys) Diet and a Yeast Culture Supplemented to the Low CP/lys Diet on Growth and Carcass Characteristics in Growing-finishing Pigs

  • Ha, Seung-Ho;Park, Byung-Chul;Son, Seung Won;Ha, Duck-Min;Lee, C. Young
    • Journal of Animal Science and Technology
    • /
    • v.54 no.6
    • /
    • pp.427-433
    • /
    • 2012
  • The present study was performed to investigate long-term effects of the low-crude protein and lysine (low CP/lys) diet and a yeast culture supplemented to the low CP/lys diet on growth and carcass characteristics in growing-finishing pigs. Forty-five gilts and 45 barrows weighing approximately 25 kg born to Yorkshire ${\times}$ Landrace dams and Duroc sires were allocated to nine pens, with five gilts and five barrows assigned per pen. Every three pens received CP/lys-rich grower and finisher diets (control), low CP/lys grower and finisher (basal), or the low CP/lys grower and finisher supplemented (2%) with a yeast culture providing $3.2{\times}10^8$ Saccharomyces cerevisiae cells/kg diet (yeast) for 31 and 79 days, respectively. The ADG was less in the low CP/lys (basal + yeast) group than in the control group (P<0.01) during both grower (0.59 vs. 0.70 kg) and finisher (0.75 vs. 0.89 kg) phases. However, marbling score was greater (P<0.05) in the low CP/lys group vs. control (3.86 vs. 3.12) at slaughter, which resulted in a twice percentage of the $1^+$-quality grade carcasses in the former compared with that for the latter. Supplementation of the yeast culture to the basal diet caused a decrease in ADG during the grower phase (P<0.01), but not during the finisher phase (0.64 vs. 0.53 kg and 0.73 vs. 0.77 kg for the basal vs. yeast group during the grower and finisher phases, respectively), without influencing the marbling score or percentage of the $1^+$-quality grade carcasses. In conclusion, results indicate that long-term provision of the low CP/lys diet has a beneficial effect on marbling and carcass quality grade as well as a negative effect on weight gain and that the yeast culture supplemented to the low CP/lys diet has no beneficial effect on weight gain or carcass quality.

The development and application of on-line model for the prediction of roll force in hot strip rolling (얼간 사상 압연중 압하력 예측 모델 개발 및 적용)

  • Lee J. H.;Choi J. W.;Kwak W. J.;Hwang S. M.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 2004.08a
    • /
    • pp.175-183
    • /
    • 2004
  • In hot strip rolling, a capability for precisely predicting roll force is crucial for sound process control. In the past, on-line prediction models have been developed mostly on the basis of Orowan's theory and its variation. However, the range of process conditions in which desired prediction accuracy could be achieved was rather limited, mainly due to many simplifying assumptions inherent to Orowan's theory. As far as the prediction accuracy is concerned, a rigorously formulated finite element(FE) process model is perhaps the best choice. However, a FE process model in general requires a large CPU time, rendering itself inadequate for on-line purpose. In this report, we present a FE-based on-line prediction model applicable to precision process control in a finishing mill(FM). Described was an integrated FE process model capable of revealing the detailed aspects of the thermo-mechanical behavior of the roll-strip system. Using the FE process model, a series of process simulation was conducted to investigate the effect of diverse process variables on some selected non-dimensional parameters characterizing the thermo-mechanical behavior of the strip. Then, it was shown that an on-line model for the prediction of roll force could be derived on the basis of these parameters. The prediction accuracy of the proposed model was examined through comparison with measurements from the hot strip mill.

  • PDF

A Study on the Optimal Cutting Depth upon Surface Roughness of Al Alloy 7075 in High-speed Machining (알루미늄 합금 7075의 표면 거칠기에 미치는 고속가공의 최적 절삭 깊이에 관한 연구)

  • Bae, Myung-Whan;Park, Hyeong-Yeol;Jung, Hwa
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.21 no.5
    • /
    • pp.74-81
    • /
    • 2013
  • The high-speed machining in the manufacturing industry field has been widely applied for parts of vehicles, aircraft, ships, electronics, etc., recently, because the effect of cost savings for shortening processing time and improving productivity is great. The purpose in this study is to investigate the effect of cutting depth on the surface roughness of workpiece with the spindle rotational speed and feed rate of high-speed machines as a parameter to find the optimal depth in the finishing for ball end mill of the aluminum alloy 7075 which is used much in aircraft parts. When the cutting depth for the respective feed rate and spindle rotational speed is varied from 0.1 mm to 0.7 mm at intervals of 0.2 mm in the wet finishing of the aluminum alloy 7075 by the insoluble cutting oils and high-speed machining used in the rough machining of previous study, the surface roughness values and the cutting temperature are measured. In addition, the cutting surface shapes of test specimens are observed by optical microscope and compared with respectively. It is found that the surface roughness values and the temperature generated during machining are increased as the feed rate and cutting depth are raised, but those are decreased as the spindle rotational speed is increased.

Anticorit Prelube oils for sheet metal forming Lubricity joined to corrosion protection for steel mill and automotive press shop application

  • LOSCH A.;KUBICKI F.
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
    • /
    • 2004.11a
    • /
    • pp.249-254
    • /
    • 2004
  • The pressing of car body parts is one of the most important sheet metal drawing processes. The corrosion protection oil applied by the steel mills plays a part in every sheet metal forming operation and also makes up the largest proportion of lubricants used. The idea to combine the corrosion protection properties of a corrosion preventive oil with the lubricity of a drawing oil lead to the development of the Anticorit prelubes. Applied at the finishing lines of the steel mills, they finally serve as lubricant in the press shops. A prerequisite for the suitability of a prelube-type oil is the absolute compatibility with all single processes from the coil to the Body in White. The use of prelubes in steel mills reduces the number and quantity of spot lubricants for additional press shop oiling dramatically. But their true benefits can only be fully achieved if the compatibility principle is applied throughout the manufacturing chain. Therefore, modem prelubes systems are modular, even different viscosities can be part of the same concept. This results in a far-reaching multifunctionality of the Anticorit prelube system for all applications.

  • PDF

Improving the Performance of Hot Rolling Process through Cross Control (Cross Control 기법을 통한 열연 공정의 성능 개선)

  • Jung, Jae-Kyung;Park, Ju-Hyun;Shim, Woo-Chul;Kwon, Oh-Min;Won, Sang-Chul
    • Proceedings of the KIEE Conference
    • /
    • 1999.11c
    • /
    • pp.561-563
    • /
    • 1999
  • The looper of a hot strip finishing mill is installed between each pair of stands and plays a key role to enhance the product quality of strip by controlling the tension and height of strip in each inter-stand. Though the conventional looper control has achieved the mass products of strip so far, it has difficulties not only tuning gains by means of errors which are caused by coupling effects between strip tension and looper angle both utilizing tension feedback. Therefore, the non-interactive control employing cross controller and tension feedback has been introduced in looper control system in order to overcome the coupling effects existing between tension and looper angle and track the reference tension efficiently. In this paper, we present the cross controllers which play a role to decouple reciprocal effects between tension and looper angle and show better performance.

  • PDF

Fabrication of the Fine Magnetic Abrasives by using Mechanical Alloying Process and Its Polishing Characteristics (기계적 합금화 공정을 이용한 초미세 자성연마입자의 제조 및 특성 평가)

  • Park Sung-Jun;Lee Sang-Jo
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.21 no.10
    • /
    • pp.34-41
    • /
    • 2004
  • A new method to fabricate the fine magnetic abrasives by using mechanical alloying is proposed. The mechanical alloying process is a solid powder process where the powder particles are subjected to high energetic impact by the balls in a vial. As the powder particles in the vial are continuously impacted by the balls, cold welding between particles and fracturing of the particles take place repeatedly during the ball milling process using a planetary mill. After the manufacturing process, fine magnetic abrasives which the guest abrasive particles c lung to the base metal matrix without bonding material can be obtained. The shape of the newly fabricated fine magnetic abrasives was investigated using SEM and its polishing performance was verified by experiment. It is very helpful to finishing the injection mold steel in final polishing stage. The areal ms surface roughness of the workpiece after several polishing processes has decreased to a few nanometer scales.

Effects of Varying Contact back-up Roll on the strip flatness (VCR 롤이 판평판도에 미치는 영향)

  • Chen, Xianlin;Zhang, Jie;Yang, Quan;Zhang, Quingdong
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 1998.03a
    • /
    • pp.144-147
    • /
    • 1998
  • VCR is a back-up roll with a special contour which leads to the length of the contact line between back-up roll and work becones self adjustable in accordance with the width of the strip. The simulation of a finite element model and the on-line test at production mill demonstrate that the VCR roll may keep the crown of the roll gap relatively stable, and at same time, permit the rolling pressure to be adjusted over a wider range, and increase the effect of work roll bending on the roll gap. The VCR rolls have been successfully used at the first stands of two largest cold rolling mills in China, and on-line test has been done at a wide hot strip finishing train. The use of VCR roll has created favorable conditions for subsequent rolling passes and the achievement of better flatness quality.

  • PDF

The Effect of Oxide Layer Thickness to the Scale Defects Generation during Hot finish Rolling (열연사상 압연시 스케일 결함발생에 미치는 산화피막 두께의 영향)

  • 민경준
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 1999.08a
    • /
    • pp.412-422
    • /
    • 1999
  • Scale defects generated on the strip surface in a tandem finishing mill line are collected from the strip trapped among the production mills by freezing the growing scale on the strip by the melt glass coating and shutting down the line simultaneously. The samples observed of its cross sectional figure showed the process of scale defect formation where the defects are formed at the base metal surface by thicker oxidized scale during each rolling passes. The properties of the oxidized layer growth both at rolling and inter-rolling are detected down sized rolling test simulating carefully the rolling condition of the production line. The thickness of the oxidized layer at each rolling pass are simulated numerically. The critical scale thickness to avoid the defect formation is determined through the expression of mutual relation between oxidized layer thickness and the lanks of the strip called quality for the scale defects. The scale growth of scale less than the critical thickness and also to keep the bulk temperature tuning the water flow rate and cooling time appropriately. Two units of Inerstand Cooler are designed and settled among the first three stands in the production line. Two units of scale defect is counted from the recoiled strip and the results showed distinct decrease of the defects comparing to the conventionaly rolled products.

  • PDF