• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2001년도 제33회 춘계학술대회 개최
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• pp.105-113
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• 2001

The effect of silver particle introduction on the rolling friction of AISI 52100 steel pairs has been investigated. Experiments were performed in dry conditions using a thrust bearing-type rolling test rig at a load range of 12 - 960 N and a sliding velocity range of 8 - 785 mm/sec with pure(99.99%) silver particles. Results showed that the introduced silver particles formed transfer layer, which protected virgin bearing surfaces and resulted in low rolling friction. By changing the quantity of silver particles, transitions in the rolling friction wear found. Results also showed that the variations in normal load and rolling speed also affected the rolling friction behavior. Analyses using SEM and EPMA showed that tile formation of transfer layer was mainly governed by the silver particle quantity, normal load and rolling speed, and this resulted in the different behavior of rolling friction. In this study, it was found that the low and stable rolling friction was resulted from the shakedown phenomena occurred at the silver transfer layer.

• 대한기계학회논문집
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• 제16권7호
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• pp.1363-1372
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• 1992

본 연구에서는 고속 냉간 압연유를 개발하기 위한 기초 연구로써 압연유의 기본이 되는 기유의 종류와 압연유에 첨가되는 각종 첨가제중 고속, 고압하 압연에서 가장 문제가 되는 히트 스크래치를 방지하는 역할을 하는 극압제의 종류 및 함량이 압연유의 윤활성과 내소부성에 어떠한 영향을 주는가를 소다식 진자형 마찰계수 시험 기, Falex 시험기 그리고 Four Ball 시험기와 같은 실험실적 평가방법과는 달리 실제 롤과 스트립 사이의 접촉조건이 상사한 시험압연기를 사용한 윤활성 및 내소부성 평가 실험을 통하여 검토하였다. 본 평가 실험에 사용된 시험압연기는 압하배분, 압연 채 터링(chattering), 장력 제어, 압연윤활 특성, 압연재 형상 제어, 이주속 압연특성 등 을 시험할 수 있는 다목적 냉간압연기로써 그 구조와 제원을 Fig.1과 Table 1에 나타 내었다. 또한 극압제를 함우하고 있는 압연유와 스트립 표면간의 화학반응에 의한 극압막의 존재여부를 확인하기 위하여 EDS(energy dispersive spectrometer) 분석법과 ESCA (electron spectroscopy for chemical analysis) 분석법을 이용하여 분석하였다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 춘계학술대회논문집
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• pp.160-163
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• 2003

For the purpose of rolling hard metals such as silicon steel and non-ferrous metals, the backup roll driven-type mill has been widely used in cold rolling industry. Since the backup roll drive results in horizontal bending of the work rolls and therefore exerted reciprocal action on the roll gap contour, the selection of slim work rolls is very restricted. In this paper, we present an analytic equation based scheme to determine a proper horizontal position of work roll minimizing the horizontal force subject to mechanical constraints.

• 조명전기설비학회논문지
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• 제27권6호
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• pp.59-67
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• 2013

This paper presents a neural net type process model for enhancing learning compensation function in hot strip finishing rolling mill. Adequate input and output variables of process model are chosen, the proposed model was designed as single layer neural net. Equivalent carbon content, strip thickness and rolling speed are suggested as input variables, and looper's manipulation variable is proposed as output variable. According to simulation result using process data to show the validity of the proposed process model, neural net type process model's outputs give almost similar data to process output under same input conditions.

• Tribology and Lubricants
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• 제17권6호
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• pp.417-426
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• 2001

The effect of silver particle introduction on the rolling friction of AISI 52100 steel pairs has been investigated. Experiments ware performed in dry conditions using a thrust bearing-type rolling test rig at a load range of 12-960 N and a sliding velocity range of 8-785 mm/sec with pure (99.99%) silver particles. Results showed that introduced silver particles formed transfer layers, which protected the virgin bearing surfaces and resulted in the low lolling friction. By changing the quantity of silver particles, transitions in the rolling friction were found. Results also showed that the variations in normal load and rolling speed also affected the rolling friction behavior. Analyses of SEM and EPMA showed that the formation the transfer layer was mainly governed by the silver particle quantity, normal load and rolling speed, and this resulted in the different behavior of rolling friction. In this study, it was found that the low and stable rolling friction was resulted from the, shakedown phenomena occurred at the silver transfer layer.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.438-441
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• 2004

Reduction of a ship's rolling is the most important performance requirement for improving the safety of the crew on board and preventing damage to cargos as well as improving the comfort of the ride. A mass driving anti-rolling system (MD-ARS) might be one candidate of several systems against the ship's rolling. In this paper, a sea-trial test on a pendulum-type MD-ARS passively operated is carried out in Suyoung, Busan. After the system is installed on the cabin of the small leisure boat, a series of test is conducted before and after operating the system. Through the test, it is confirmed that the roll rate of the ship is pretty well reduced by the system.

• 한국정밀공학회지
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• 제21권10호
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• pp.57-64
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• 2004

The objective of this study is to suggest the form rolling technology to produce high precision worm on the base of three dimensional finite element simulation and experiment. It is important to determine the initial workpiece diameter in form rolling because it affects the quality of tooth profile. The calculation method of the initial workpiece diameter in form rolling is suggested and it is verified by finite element simulation. The form rolling processes of worm shaft used as automotive part using both the rack dies of counter flow type and the roll dies are considered and simulated with the same numerical model as actual process by the commercial finite element code, BEFORM-3D. Deformation modes of workpiece between the form rolling by the rack dies of counter flow type and the roll dies are investigated from the result of simulation. The experiments using rack dies and roll dies are performed under the same conditions as those of simulation. The surface roughness, the straightness and the profile of worm are measured precisely using the worm shafts obtained from experiment. The results of simulation and experiment in this study show that the form rolling process of worn shaft using the rack dies is decidedly superior to that using roll dies from the aspect of the precision of worm such as the surface roughness, the straightness and the profile of worm.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.544-548
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• 2007

In general, final width of hot strip should be accomplished in this stage because width reduction of strip hardly appears during typical finishing mill. However, it is difficult to control the width of strip in the roughing mill process as the horizontal rolling of strip is subsequently performed after the vertical rolling. It is therefore important to obtain the deformation rolling direction on strip width to minimize the width spread of strip during horizontal rolling after vertical rolling. Generally there is Sizing press type and Edger-roll type. The width reduction process in sizing press has small amount of width spread compared with the edger. However, productivity by the sizing press process is much lower than those of the edger. In this study, sizing press and Edger-roll process parameters in a sheet rolling mill were set at specified values and the effect of the change in these parameters on product quality and process performance were evaluated.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 춘계학술대회 논문집
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• pp.55-55
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• 2009

• 한국소음진동공학회논문집
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• 제20권7호
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• pp.629-636
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• 2010

A Mobile Harbor is a new transportation platform which can load and unload has containers to and from very large container ships on the sea. Currently designed Mobile Harbor a catamaran type which is equipped with precisely controlled gantry crane on the deck, and can transport 250 TEUs at a time. Loading and unloading works by crane require very small motion of Mobile Harbor in waves, because it may be operated outside of harbors. In this project, applicability of both tuned-type anti-rolling tank and maglev-type active mass driver is studied as anti-rolling systems.