• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2006년 추계학술발표대회 개요집
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• pp.128-129
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• 2006

To investigate impact property characteristics on the low temperature plate weld metal, the two different plates of the same steel grade were welded and evaluated by Mo bearing and no Mo containing welding consumables. The results are summarized as follows; 1) Multi pass welded Mo bearing weldment was not satisfied with the requirement of tensile strength, while no Mo containing one was satisfied with it 2) In the plate butt weldment, the impact property of weld metal was highly affected by both the welding consumable and plate.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.119-124
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• 2001

Currently knowledge of strain in welds has mainly been obtained form strain gaging method:; that is directly attaching most of the material to the gate. The very few non-contact method are still in the early stage. One of the non-contact methods is by the use of the laser that has high-level of the accuracy for the measurement, and this laser also has excellent characteristics on which many studies for its applications are focused throughout the many fields. The dissertation is on the measurement of the strain caused by the characteristics and the temperature changes of the TIG welded zone which is used with 3D ESPI system that is functionally modified through the laser ESPI system. This system employed the aluminum sheet-metal which are mainly used for the steel plate such as for the electronics, chemisry, food instrument and electronic appliances.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 춘계학술대회 논문집(한국공작기계학회)
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• pp.155-161
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• 2001

Currently knowledge of strain in welds has mainly been obtained from strain gaging method; that is directly attaching most of the material to the gage. The very few non-contact method are still in the early stage. One of the non-contact methods is by the use of the laser that has high-level of the accuracy for the measurement, and this laser also has excellent characteristics on which many studies for its applications are focused throughout the many fields. The dissertation is on the measurement of the strain caused by the characteristics and the temperature changes of the TIG welded zone which is used with 3D ESPI system that is functionally modified through the laser ESPI system. This system employed the aluminum sheet-metal which are mainly used for the steel plate such as for the electronics, chemistry, food instrument and electronic appliances.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 춘계학술대회 논문집(한국공작기계학회)
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• pp.208-213
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• 2001

Objective of this paper is to develop a new approach involving the use of an Artificial Neural Network(ANN) and multiple regression methods in the prediction of process parameters on bead height for GMA welding process. Using a series of robotic are welding, multi-pass butt welds carried out in order to verify the performance of the neural network estimator and multiple regression methods. To verify the developed system, the design parameters of the neural network estimator are selected from an estimation error analysis. The experimental results show that the proposed models can predict the bead height with reasonable accuracy and guarantee the uniform weld quality.

• 한국공작기계학회논문집
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• 제13권6호
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• pp.119-126
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• 2004

The welding characteristics of Inconel 600 Alloy using a continuous wave Nd:YAG laser are experimentally investigated. The major process parameters studied in the present laser welding experiment were the positions of focus, laser power and travel speed of laser bean We measured the fusion zone size and its shape using an optical microscope for the observation of cross-sectional area. We performed two tests regarding the tension and the micro hardness for welding quality estimation. Then we measured residual stress in welds by electronic speckle pattern interferometry(ESPI). In conclusion the optimum butt welding process parameters were 0.5mm focus position, 1.6kW laser power, 1m/min travel speed and 5.5$\ell$/min assist gas discharge.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 추계학술대회 논문집
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• pp.226-234
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• 2000

The friction stir welding technique is a derivative of conventional friction welding, which enables the advantages of solid-phase welding to be applied to the fabrication of long butt and lap joints, with very little postweld distortion. Friction stir welding is a remarkable new welding technique for joining aluminum alloys and has the potential for welding other ferrous materials. It has already been developed beyond a laboratory curiosity and has been proved as a potential practical welding technique offering low-distortion, high-quality, low-cost welds from simple concept machine tool welding equipment. To bring this remarkable method of welding aluminum alloys to the attention of Industry, this article introduces the basic principle of friction stir welding, pointing out the practical advantages and most important of all, describes the exceptionally good metallurgical and mechanical properties.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2003년도 추계학술발표대회 개요집
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• pp.191-193
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• 2003

S-N fatigue tests were conducted to investigate the fatigue strength of the small diameter socket and butt welded joints of carbon steels. Experimental parameters were pipe diameter, throat depth, shape of socket welds and welding procedure. Filler metals used in SMAW and GTAW procedure were E9016-G with diameter of 4.0 mm and ER70S-G with diameter of 2.4 m. API 5L Gr.B pipes were adopted as a small diameter branch pipes. All socket fittings were machined from ASTM A105 carbon steel. Fatigue strength in socket weld joints increased with increasing pipe diameter, area of weld metal and weld leg length of pipe side.

• Journal of Welding and Joining
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• 제7권4호
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• pp.12-21
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• 1989

Laser beam welding parameters have experimentally investigated, using a continuous wave 3kW $CO_2$ laser with the various travel speeds, beam mode and laser beam power in low carbon steels. An optimum position of focus and the effect of shielding gas on penetration depth with varying the flow range of 0.5 to 5.1m/min have been combined to investigate the effect of laser power and travel speed on penetration depth and bead width. It is found that the optimum position of focus in 3kW class laser is 0.5 to 1.5mm below the surface of the material. The flow rate of shielding gas affects the penetration depth and He is more effective than Ar. The penetration depth in laser welds of low carbon steels is between two and four times of the bead width. Laser beam welding of butt joints in 2mm thick carbon steel has been carried out to establish a weldability lobe. The lobe indicating acceptable welding conditions is introduced.

• Journal of Advanced Marine Engineering and Technology
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• 제25권4호
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• pp.791-796
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• 2001

Friction stir welding is a solid phase welding process that does not melt the metal when welding. The FSW is the most remarkable and potentially useful new welding technique that is still in development. Friction stir butt welding process on 2 mm thick Al 1050 plates by utilizing a milling machine was experimentally studied. With the optimized heat generating tool welds could be achieved that are void and crack free. It was found that the friction stir welded tensile test specimens failed in the HAZ outside of the weld metal, and that the tensile strength was above 90% of that of the base metal.

• International Journal of Korean Welding Society
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• 제1권2호
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• pp.1-6
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• 2001

A weld quality assessment method is proposed in this work, which can be applied to the short-circuit mode in GMAW. Information about the welding signal trajectory, distribution of the signal duration at each sub-regions and short-circuit frequency is used to evaluate the weld quality. The weighted penalty, which is determined experimentally, is imposed for each abnormal signal. Performance of the proposed method is compared with the Simpson's method under the conditions of shielding gas reduction, workpiece surface contamination and joint gap in the butt and fillet welds. Although the proposed method predicts the weld quality with reasonable accuracy, further modification and extension to other metal transfer modes are needed as a further study.