• 한국정밀공학회지
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• 제20권1호
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• pp.179-186
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• 2003

This paper is to investigate the wear behavior of submerged-arc claddings by the wear test with a ball-on-disk type wear testing machine in air. The specimens were clad with Stoody105 alloy wire on a medium carbon steel (SM45C) substrate by submerged-arc cladding process under different welding parameters. The wear behavior of the cladding through ball-on-disk test has been studied under the wear load from 5 to 16 N and the sliding speed from 8 to 35 cm/s. The weight loss of the specimen was measured. Scanning electron micrographs of the worn surface show a layer of oxide film formed on the worn surface. Oxidation wear mechanism controls the wear process. The spatting of the oxide is caused by the repeated rubbing fatigue mechanism.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1154-1159
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• 2004

Laser beam welding is increasingly being used in welding of structural steels. The laser welding process is one of the most advanced manufacturing technologies owing to its high speed and deep penetration. The thermal cycles associated with laser welding are generally much faster than those involved in conventional arc welding processes, leading to a rather small weld zone. Experiments are performed for Inconel 600 plates changing several process parameter such as laser power, welding speed, shielding gas flow rate, presence of surface pollution, with fixed or variable gap and misalignment between plate and plate, etc. The follow conclusions can be drawn that laser power and welding speed have a pronounced effect on size and shape of the fusion zone. Increase in welding speed resulted in an increase in weld depth/ aspect ratio and hence a decrease in the fusion zone size. The penetration depth increased with the increase in laser power . Welding characteristics of austienite Inconel 600 using a continuous wave Nd:YAG laser are experimentally investigated. This paper describes the weld ability of inconel 600 for machine structural use by Nd:YAG laser.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1996년도 춘계학술대회 논문집
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• pp.177-182
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• 1996

The objective of this thesis is to investigate the influence of welding residual stresses on the fatigue growth behavior of welding residual stresses on the fatigue growth behavior of cracks located transverse to the weld bead. For this purpose, G.T.A. (Gas Tungsten Arc) welding was performed on the Al. Alloy 1100-0 plate and the same initial crack is made on HAZ(Heat Affected Zone), weld metal and base metal respectively. C.T.(Compact Tension) specimens were used as experimental material. Initial welding residual stresses were measured by using strain gage sectioning method. All specimens were tested under constant amplitude load with stress ratio R=0.1

• 전력전자학회:학술대회논문집
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• 전력전자학회 2008년도 하계학술대회 논문집
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• pp.624-627
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• 2008

It is generally used the boost converter for the welding machine using fuel cell. But this type generates the duplicate loss between boost converter and inverter. As a result, the whole efficiency is lower than conventional inverter arc welder and the cost is expensive due to additional switching device. Therefore, we proposed the inverter rectification type DC-DC converter with boost converter function in fuel cell based TIG welder. The performance of the proposed technique is evaluated on a 1.2kW fuel cell stack based experimental prototype circuit.

• Journal of Welding and Joining
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• 제24권5호
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• pp.37-42
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• 2006

The robotic arc welding is widely employed in the fabrication industry fer increasing productivity and enhancing product quality by its high processing speed, accuracy and repeatability. Basically, the bead geometry plays an important role in determining the mechanical properties of the weld. So that it is very important to select the process variables for obtaining optimal bead geometry. In this paper, the possibilities of the Infrared camera in sensing and control of the bead geometry in the automated welding process are presented. Both bead width and thermal images from infrared thermography are effected by process parameters. Bead width and isotherm radii can be expressed in terms of process parameters(welding current and welding speed) using mathematical equations obtained by empirical analysis using infrared camera. A linear relationship exists between the isothermal radii producted during the welding process and bead width.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 추계학술대회 논문집
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• pp.170-174
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• 2004

Despite the widespread use in the various manufacturing industries, the full automation of the robotic CO$_2$ welding has not yet been achieved partly because the mathematical model for the process parameters of a given welding task is not fully understood and quantified. Several mathematical models to control welding quality, productivity, microstructure and weld properties in arc welding processes have been studied. However, it is not an easy task to apply them to the various practical situations because the relationship between the process parameters and the bead geometry is non-linear and also they are usually dependent on the specific experimental results. Practically, it is difficult, but important to know how to establish a mathematical model that can predict the result of the actual welding process and how to select the optimum welding condition under a certain constraint. In this paper, an attempt has been made to develop an Radial basis function network model to predict the weld top-bead width as a function of key process parameters in the robotic CO$_2$ welding. and to compare the developed model and a simple neural network model using two different training algorithms in order to verify performance. of the developed model.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2005년도 춘계학술대회 논문집
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• pp.66-70
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• 2005

The full automation of welding has not yet been achieved partly because the mathematical model for the process parameters of a given welding task is not fully understood and quantified. Several mathematical models to control welding quality, productivity, microstructure and weld properties in arc welding processes have been studied. However, it is not an easy task to apply them to the various practical situations because the relationship between the process parameters and the bead geometry is non-linear and also they are usually dependent on the specific experimental results. Practically, it is difficult, but important to know how to establish a mathematical model that can predict the result of the actual welding process and how to select the optimum welding condition under a certain constraint. In this paper, an attempt has been made to develop an neural network model to predict the weld top-bead height as a function of key process parameters in the welding. and to compare the developed model and a simple neural network model using two different training algorithms in order to select an optimal neural network model.

• 문화기술의 융합
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• 제9권1호
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• pp.605-611
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• 2023

본 연구에서는 자연환경에 영향을 주는 에너지를 절감하기 위해 피복아크용접에서 가동철심형 용접기와 전력사용량이 적은 디지털 용접기(인버터 방식)를 비교하여 전력 사용은 적으며 용접성은 동일한 조건을 갖춰야 하는 부분을 확인하고자 한다. 가동철심형 용접기는 정현파를 출력하는 교류를 사용하며 디지털 용접기 또한 정현파 교류를 발생시켜 동일 조건을 갖추고 전력사용량은 적으며 같은 용접성을 갖추어야 한다. 다만 용접성은 다양하게 검증할 수 있으나 국가기술자격 용접 분야의 자격시험으로 한정하여 분석하고자 한다.

• 조명전기설비학회논문지
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• 제22권6호
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• pp.26-33
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• 2008

본 연구에서는 일반적으로 용접기의 전원장치로 사용되어지는 풀-브리지 회로에 1개의 스위치와 1개의 무손실스너버 부분 공진 커패시터로 구성된 간단한 액티브 보조 부분 공진 스너버를 추가한 새로운 풀-브리지 소프트 스위칭 PWM DC-DC 컨버터를 제안하였다. 제안한 풀-브리지 소프트 스위칭 DC-DC 컨버터 회로는 각 액티브 스위치에 인가된 전압이 DC 버스 라인 전압의 1/2로 되기 때문에 AC 400(V)계 상용전원 라인에 적용할 경우에도 600(V)내압의 스위칭 소자(IGBT)가 적용 가능하며, 기존 회로의 DC버스 라인 스위치에 발생되는 도통 손실을 저감하여 고주파 변압기의 1차측의 전류가 2차측보다 작아지는 저 전압, 대전류 직류 출력을 얻어 수 있었다. 그리고 모든 영역에서 ZCS/ZVS 동작함으로써 저전압, 대전류 직류 출력의 스위칭 전원 장치에 있어 고주파, 고효율, 고출력을 실현할 수 있다. 이러한 모든 사항은 시뮬레이션과 실험 결과로부터 도출하였으며, 제안한 회로의 단점을 보완할 경우에는 차세대형 TIG MIG MAG 아크 용접기용 전원으로 용이할 것으로 판단된다.

• 한국공작기계학회논문집
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• 제11권4호
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• pp.89-96
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• 2002

This paper aims to develop an intelligent model for predicting top-bead width for the robotic GMA(Gas Metal Arc) welding process using BP(Back-propagation) neural network and multiple regression analysis. Firstly, based on experimental data, the basic factors affecting top-bead width are identified. Then BP neural network model and multiple regression models of top-bead width are established. The modeling methods and procedure are explained. The developed models are then verified by data obtained from the additional experiment and the predictive behaviors of the two kind of models are compared and analysed. Finally the modeling methods, predictive behaviors md the advantages of each models are discussed.