• Proceedings of the KWS Conference
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• 2007.11a
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• pp.124-126
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• 2007

The study was performed in order to develop high efficient Electrode Gas Welding with additional solid wire by means of a surplus heat source. This technique can be reduced welding heat input in the weldments, welding speed can be increased over 30%, and mechanical properties can be more excellent than traditional method.

• International Journal of Korean Welding Society
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• v.3 no.2
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• pp.15-23
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• 2003

A genetic algorithm was applied to an arc welding process to determine near optimal settings of welding process parameters which produce good weld quality. This method searches for optimal settings of welding parameters through systematic experiments without a model between input and output variables. It has an advantage of being able to find optimal conditions with a fewer number of experiments than conventional full factorial design. A genetic algorithm was applied to optimization of weld bead geometry. In the optimization problem, the input variables were wire feed rate, welding voltage, and welding speed, root opening and the output variables were bead height, bead width, penetration and back bead width. The number of level for each input variable is 8, 16, 8 and 3, respectively. Therefore, according to the conventional full factorial design, in order to find the optimal welding conditions, 3,072 experiments must be performed. The genetic algorithm, however, found the near optimal welding conditions from less than 48 experiments.

• Journal of Welding and Joining
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• v.18 no.5
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• pp.63-69
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• 2000

A genetic algorithm was applied to an arc welding process to determine near optimal settings of welding process parameters which produce good weld quality. This method searches for optimal settings of welding parameters through systematic experiments without a model between input and output variables. It has an advantage of being able to find optimal conditions with a fewer number of experiments than conventional full factorial design. A genetic algorithm was applied to optimization of weld bead geometry. In the optimization problem, the input variables was wire feed rate, welding voltage, and welding speed and the output variables were bead height, bead width, and penetration. The number of level for each input variable is 16, 16, and 8, respectively. Therefore, according to the conventional full factorial design, in order to find the optimal welding conditions, 2048 experiments must be performed. The genetic algorithm, however, found the near optimal welding conditions from less than 40 experiments.

• International Journal of Korean Welding Society
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• v.1 no.1
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• pp.44-50
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• 2001

A genetic algorithm was applied to the arc welding process as to determine the near-optimal settings of welding process parameters that produce the good weld quality. This method searches for optimal settings of welding parameters through the systematic experiments without the need for a model between the input and output variables. It has an advantage of being capable to find the optimal conditions with a fewer number of experiments rather than conventional full factorial designs. A genetic algorithm was applied to the optimization of the weld bead geometry. In the optimization problem, the input variables were wire feed rate, welding voltage, and welding speed. The output variables were the bead height bead width, and penetration. The number of levels for each input variable is 16, 16, and 8, respectively. Therefore, according to the conventional full factorial design, in order to find the optimal welding conditions,2048 experiments must be performed. The genetic algorithm, however, found the near optimal welding conditions in less than 40 experiments.

• Laser Solutions
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• v.8 no.3
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• pp.11-19
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• 2005

In automotive industry, light weight vehicle is one of issues because of the air pollution and the protection of environment. Therefore, automotive manufacturers have tried to adopt light materials such as aluminum alloy to production line. Aluminum welding using laser has some advantages high energy density and high productivity. It is very important to understand weld characteristic according to welding condition in order to determine the possibility of application to car body. In this study, Nd:YAG laser welding of 5182 aluminum alloy with filler wire AA5356 was carried out through experimental design according to wire feed rate, laser power and welding speed. Weld bead shape in terms of cross section photo, bead with, height of reinforcement and penetration depth and mechanical property in terms of tensile strength and formability was investigated. Analysis of variation (ANOVA) was performed to know the effect of weld parameter for weldability, laser power was statistically most significance factor of three variables.

• Proceedings of the KWS Conference
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• 1997.05a
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• pp.55-56
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• 1997

• Proceedings of the KWS Conference
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• v.43
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• pp.237-239
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• 2004

• Proceedings of the KWS Conference
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• 2001.05a
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• pp.62-64
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• 2001

• Journal of Welding and Joining
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• v.31 no.1
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• pp.26-32
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• 2013

Recently, welding technology of nonferrous metals which were difficult to implement by arc welder has become available through digitalization of arc welding machine. Among them, the welding quality improvement of aluminum welding is very noticeable. These results increase the arc stability by controlling arc current and voltage waveform precisely, and control wire feed speed by synchronizing with arc current which the feed rate of filler wire is controlled by a precise motor control of servomotor and not by a simple constant speed feeding. Not only through the hardware digitalization of arc welding machine but also through advance of software of arc welding, it became possible to implement a certain level of welding quality by a simple operation. These led to CMT welding process implementation which requires low heat input than current arc welding and highly increased the applicability of the aluminum welding.

• Journal of Welding and Joining
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• v.32 no.2
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• pp.18-21
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• 2014

Cold cracking of weldment is one of the most serious welding problems. A sufficient quantity of diffusible hydrogen, a residual stress, and a sensitive microstructure are the causes of cold cracking. Removal of any one of these factors can be used to prevent cold cracking. Application of flux cored arc welding process is increasing due to high productivity and easiness of welding. In addition, to prevent cold cracking in the HAZ or weldment, preheat temperature and interpass temperature have to be controlled. In this study, the effect of preheat temperature on the levels of diffusible hydrogen in the weld metal deposited using flux cored wire was examined. The levels of preheat temperature of base metal specimen were ambient temperature, 50, 100 and $150^{\circ}C$ respectively. The result showed that the increase of preheat temperature was a linear relationship with reduction of diffusible hydrogen content in weldment.