• 한국생산제조학회지
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• 제7권4호
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• pp.50-55
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• 1998

Mould level control system for continuous casting process involves stick-slip friction in the sliding gate , time-delay, non-linearity, and certain uncertainties such as friction force variations between molten steel and the inner wall of mould. In this paper, sliding mode control technique was used to solve these complex control problem. The controller is then designed and implemented onto the continuous casting process. Testing result shows that sliding mode controller can decrease the fluctuating magnitude of the mould level and is superior to the existing PID controller.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.387-392
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• 2002

A portable mould oscillation analyzer with an integrated computer, developed by POSCO, records the movement of the mould in every spatial direction. The system uses the gap sensors to measure the mould movement (displacement) in two horizontal directions according to the mould narrow and broad faces and the vertical strokes in the four corners of mould. The gap sensor is a non-contacting minute displacement-measuring device using the principle of high frequency eddy current loss. The mould oscillation diagnostic system integrates the gap sensors, their converters and the industrial portable computer with plug-in data acquisition boards. In an own expert module, which is included in the diagnosis program, one can obtain much information about the mould oscillation equipment.

• 한국주조공학회지
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• 제16권2호
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• pp.116-123
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• 1996

The equipment for the horizontal continuous casting was built to produce hyper-eutectic Al-Si bars with a small cross-section of 25mm in diameter. The manufacturing processes including withdrawal cycle and secondary cooling methods were modified to refine the primary and the eutectic Si. The longitudinal casting speeds varied over the ranges of 670-1100mm/min for pure Al, and 200-350mm/min for Al-17wt%Si alloy. Due to the difference of cooling rate in the mould, microstructural asymmetry between the lower and the upper part of bar was observed. Thus, manufacturing processes such as cooling and withdrawal method were optimally combinated to get the homogeneous cast structure. With the increase of casting speed, the primary Si size was refined down to $30{\mu}m$ near the surface, and $80{\mu}m$ in the center of the bar.

• 한국산학기술학회논문지
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• 제16권5호
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• pp.2993-2999
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• 2015

강 제조 회사들은 연속주조금형의 표면을 보호하기 위해 Ni-B 또는 Ni-Co 합금 도금을 적용하고 있으며, 도금 층에 균열이 생기게 하는 황을 함유한 사카린 윤활제를 사용하고 있다. 균열 및 인장 응력을 유발하는 것은 Ni-S 화합물로 여겨진다. Ni-Mn-B 삼원합금은 Ni-S 화합물이 형성되기 이전에 Mn-S 화합물을 형성하여 균열을 억제하기 위해서 개발되었으나, Ni-Mn-B 합금 도금에 관한 국내나 해외 기준이 없다. 그리하여 새로이 개발된 Ni-Mn-B 도금을 평가하기 위한 신뢰성 평가기준을 개정하려한다. 가속수명시험을 개발하기 위해 FMEA(고장형태 영향분석)가 사용되어 도금의 주요 파괴 원인을 분석하였다. Ni-Mn-B 신뢰성 기준은 가속수명시험 방법을 포함하였고, 기본 성능 시험과 환경시험, 가속수명시험으로 분류되었으며, 80% 신뢰수준으로 B10수명 1 000시간을 보장하도록 고안되었다.