• Proceedings of the Korean Society of Marine Engineers Conference
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• 2012.06a
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• pp.172-172
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• 2012

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.3
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• pp.439-445
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• 2013

This study is on the system that can integrate generator and charger to use as a welder and generator for need. Specifically, it was hybrid generator consisted with select switch to use generator controller and multiple function welder, that function were auto-stopping generator when generator power finish to recharge in recharger battery and Co2 MMA TIG MIG MAG are devide depend on supplying gas. This control system of voltage, high-frequency, motor and gas valve was implemented in order to improve the performance and convenience of existing welders to choose only one or two at a time.

• Proceedings of the KWS Conference
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• 2001.05a
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• pp.108-109
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• 2001

• Journal of Welding and Joining
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• v.23 no.1
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• pp.41-47
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• 2005

Arc pressure is one of important factors in understanding physical arc phenomena. Especially it affects on the penetration, size and shape of TIG welding. Some researches were reported on the effect of arc pressure in low and middle current region. But there are not any research in high current region. The purpose of this study is to investigate the arc pressure distribution with mixing ratio of shield gas such as Ar and He gases. A Cu block with water cooling was specifically designed and used as an anode electrode in order to measure the arc pressure in high current region. Then, the arc pressure distribution was measured with change in welding current and mixing ratio of shield gases. The arc force was obtained by numerically integrating the measured results. As the results, it was shown that the arc pressure was concentrated at the central part of the arc in middle and high current regions when a pure Ar gas was used. In case of Ar + He mixing gas, the arc pressure was much lower than that of pure Ar gas. In addition, it was widely distributed to radial direction.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.10
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• pp.1078-1088
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• 2012

In this paper, we present research experimental results about the different thickness T-joint welding of the high power continuous wave(CW) Nd:YAG laser for the secondary battery of a vehicle. Although the conventional method used for the secondary battery is a argon TIG welding, we utilize a laser welding to improve Tungsten Inert Gas(TIG) welding's weakness. The laser, which has a couple of advantage such as aspect ratio, low Heat Affected Zone(HAZ), good welding quality and fast productivity utilized in this work is a CW Nd:YAG laser. In order to observe laser welding sections, we used a optical microscope. Through the analysis of the metallographic, hardness, aspect ratio, and heat input, we obtained the desired data in condition of 1800 W laser beam power and 1.8 m/min and 2.0 m/min laser beam travel speeds. In order to compare electric resistances of the argon TIG welding and laser welding, we made an actual battery and the electric resistance of the laser welding is reduced by 40~45% comparing with the argon TIG welding.

• Journal of the Korean Society for Heat Treatment
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• v.17 no.4
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• pp.230-235
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• 2004

Present work was carried out to investigate the influence of welded conditions, such as welding current, diameter of welding wire on the microstructural change and mechanical properties of TIG welded joint in AZ31B Mg alloy. It was found that good and sound welded joint was achieved in all welding conditions. The grain size decreased with increasing welding current and decreasing diameter of welding wire. Also, the second phases were homogeneously distributed in the grain and grain boundary as decreasing welding current and diameter of welding wire. The ${\beta}$ discontinuos precipitates were observed in the welded joint, but this microstructure has not been reported by previous researchs in AZ31B Mg alloy. The hardness value is affected by the existence state of the second phase and the hardness of the welded joint region is lower than the other regions in welded AZ31B Mg alloy. The strength of the welded joint region was influenced by the grain size and has more than 90%, compared to that of ASTM standard specification.

• Journal of Welding and Joining
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• v.30 no.2
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• pp.47-53
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• 2012

This paper aimed to study and understand the mechanical phenomena of thermal elasto-plastic behavior on the dissimilar butt joint (Al 6061-T6 and STS304) by TIG assisted Friction Stir Welding. Heat conduction and residual stress analysis is carried out using in-house solver. Two-dimensional results of the heat distribution and residual stresses in dissimilar joint for particular tool geometry and material properties are presented. The predicted stress along longitudinal direction in Al 6061-T6 and STS304 are approximately between 12-15% of their respective yield strengths. A comparison is made between experimentally measured and numerically predicted equivalent residual stress values.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.13 no.4
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• pp.113-120
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• 2004

The object of this study is to investigate the effect of compounded welding through the AE(Acoustic Emission) characteristics for weld HAZ(Heat Affected Zone) under the static tensile test. This study was carried out an SWS 490A, high tension steel for electric shield metal arc welding(SMAW), $CO_2$ gas arc welding and TIG welding. Data displays are based on the measured parameters of the AE signals, along with environmental variables such as time and load. The accumulated AE event curve of HAZ definitely have the point of inflection subject to tensile test. The results of the tensile test of HAZ come out electric shield arc welding ＞$CO_2$ gas arc welding＞TIG welding in case of single welding, but generally the tensile test of HAZ come out electric shield arc welding＞ TIG welding ＞ $CO_2$ gas arc welding. These history plots give us useful and powerful information to analyze the results of material evaluation testing.

• Journal of Welding and Joining
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• v.24 no.4
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• pp.27-31
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• 2006

Optimization of process parameters for laser-arc hybrid welding process is intrinsically sophisticated because the process has three kinds of parameters-arc, laser and hybrid welding parameters. In this paper, the relationship between weldability and several process parameters such as laser beam-arc distance, electrode height, welding current and welding speed, were investigated by the full factorial experimental design. Weld quality was evaluated by using weight of spatters which is related with the pore area. It was found that the weld quality was increased with the increases in laser beam-arc distance and welding current, and decreased with the increases in electrode height and welding speed.

• Proceedings of the KWS Conference
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• 2005.11a
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• pp.138-140
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• 2005

Plasma arc welding(PAW) technology is a proven process that has already been adopted by other industrial fields and recently has been considered to join the tank structure of LNG carrier. The purpose of this study is to introduce PAW process for the root welding of stainless steel pipes instead of TIG welding. There are distinctive features of the PAW compared to TIG welding; higher energy density that can increase welding speed by more than twofold, and longer arc length that can be controlled to trace seam line easily because of allowable gap between workpiece and torch. However, PAW process is also very sensitive to the root gap and misalignment due to the characteristics of long and narrow arc shape. So, we have done various experiments to establish the allowable fit-up condition by changing welding parameters including arc length, with or without filler metal, groove shape, and obtained satisfactory result.