• Journal of Welding and Joining
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• 제23권1호
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• pp.69-76
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• 2005

Recently, application of arc welding to galvanized carbon steel sheet is on the increasing Ould in the fields of automobile and construction industries. In arc welding process, zinc is evaporated in weld pool, even under the appropriate welding condition and produce blowhole and/or pit. Zinc gas cause instability of arc and increase spatter and fume. This research is purposed to minimize the heat-input and the formation of porosities in the welded joint of the galvanized carbon steel sheet using variable polarity AC wave pulse MIG welding system. An appropriate welding condition which showed low spatter and good bead appearance was acquired by applying the AC pulse MIG welding machine to DC duplicated MIG welding with the solid wire. When oxygen gas was added to shield gas of MIG welding for galvanized steel sheet, arc length was increased and arc stability was improved. In the AC duplicated welding, the loss of galvanized layer was decreased as the amount of heat-input was decreased when the EN ratio was increased under the condition that average welding current was evenly set.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2003년도 추계학술발표대회 개요집
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• pp.24-26
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• 2003

In this study EB(Electron Beam) welder was modified to apply EB welder to micro-joining with solder ball and Pt wire. The power and beam current of EB welder is 6kW, 100mA and the minimum current was 1mA. The minimum current of EB welder was modified to decrease the amount of beam current to 0.0lmA and the monitoring system to observe materials was made up. The control system and CAD/CAM software for e-beam direct writing was developed and the deflection beam was controlled without moving workpieces. the possibility of applying EB welder to micro-joining with solder ball and Pt wire was studied through this experiments.

• Journal of Welding and Joining
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• 제4권2호
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• pp.21-29
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• 1986

The influence of welding heat input variation(600-900J/cm) and heat-treatment condition after welding on tensile strength of butt welded joint in $175Kg/mm^2$ strength level Maraging steel(Co-free and Co-containing) sheets was investigated on the basis of hardness distribution, microstructure of weld metal and fracture surface. The obtained main results are as follows; 1. The strength of weldment (UTS, NTS), joint efficiency showed a little decreasing tendency with the increase in welding heat input, and the elongation showed a little increasing tendency with the increase in the width of weld metal. It was considered because of the plastic constraint of the high strength base metal. 2. The strength of weldment was better in the solution treatment and aging than the aging only after welding due to the disappearance of almost denverite in weld metal. 3. The hardness distribution in weldment after welding and heat-treatment was almost similar to both Co containing and Co free Maraging steel with change in welding heat input. 4. The fracture was occurred at weld metal, and the fracture surface showed a relatively shallow dimples in both Co containing and Co free Maraging steel.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1994년도 특별강연 및 춘계학술발표 개요집
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• pp.1-20
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• 1994

In order for manufacturing companies to remain competitive it Is necessary for them to review continually their fabrication methods. The use of power beams for welding and cutting offer significant opportunities for industry to improve its product quality and increase profitability. This paper discusses a number of current industrial applications for electron beam and laser welding.

• 한국레이저가공학회지
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• 제4권1호
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• pp.39-48
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• 2001

This study was performed to evaluate basic characteristics of electron beam weldability for high strength aluminum alloys. The aluminum alloys used were A5083 and A6N01, and A7N01. The principal welding process parameters, such as accelerating voltage, beam current, welding speed and chamber pressure were investigated. The dimension and microstructure of welds were evaluated with OLM, and SEM (EDAX). In addition, weldability variation(cracking) due to process parameters was also evaluated. The degree of cracking in the EB fusion zone appears to be affected mainly by aspect ratio, such that as aspect ratio increases the cracking tendency also increases. The alloying element itself may also affect the hot cracking resistance, but its role is considered to be indirect effect such that the relatively higher vaporization pressure elements of Zn and Mg give deeper weld penetration and thus results in greater cracking tendency.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2004년도 추계학술발표대회 개요집
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• pp.79-81
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• 2004

In this study EB(Electron Beam) welder was modified to apply Ef welder to micro-joining for soldering and micro-brazing. The power and beam current of EB welder is 6kW, 100mA(60kV) and the minimum current was 1mA. The minimum current of EB welder was modified to decrease the amount of beam current to 0.0lmA and the monitoring system to observe materials was made up. The system is developed including teaching function for generating patterns. The control system and CAD/CAM software for EB direct writing was developed and the deflection beam was controlled without moving workpieces. the possibility of applying EB welder to micro-joining for soldering and brazing was studied through this experiments.

• 한국안전학회지
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• 제12권2호
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• pp.57-64
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• 1997

Fatigue crack propagation behaviors and life prediction for SUS 321 plate and its electron beam weld metal were investigated using compact tension specimens. The larger the stress ratio is, the faster the crack propagates, but the variation of crack propagation rate decreases. The effect of stress ratio is greater in the slow crack propagation area than in the faster one. The crack propagation rate of electron beam weld metal is faster than that of base metal because of hardening, weld defect and residual stress in welding area. The crack propagation rate of transverse weld metal has a lower than that of base metal due to the effect of residual stress, but in the time of passing through welding area, has a higher rate. The crack propagation rate using $\Delta$K$_{eff}$ can be well plotted regardless of stress ratio. The fatigue life prediction method of considering crack closure more exactly predicts fatigue life than conventional one. conventional one.e.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 춘계학술대회 논문집
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• pp.39-42
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• 2008

Alloy 718 nozzle component was manufactured by hot working and electron beam welding process. In this process, domestic 718 materials were applied and evaluated. Hot compression tests were carried out at a lot of process conditions and microstructural evaluation was investigated. Using the results, FEM simulations were performed in order to optimize the hot working process. After hot working, forged work-pieces were machined and welded by electron beam. Final nozzle component were heat treated and their microstructure and mechanical properties were investigated.

• Journal of Welding and Joining
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• 제13권1호
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• pp.73-77
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• 1995

이 글에서는 챔버의 용접에 대해서 기술하였다. 전자빔용접에 의하여 누설률이 1*$10^{-10}$ torr.1/sec 이하로 목표값을 만족하기 때문에 초고진공에 적합한 용접법이다. 챔버는 용접부에 trench 구조를 가져야 진공용접을 하는데 보다 효과적이다. 이것은 지금까지 전자빔 용접에서 시험되지 않은 것이기 때문에 향후 보다 많은 연구가 있으리라고 본다.

• Design & Manufacturing
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• 제14권1호
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• pp.56-62
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• 2020

An electron beam was used to mainly utilize for polishing, finishing, welding, a lithography process, etc. Due to the high technical level of difficulty of high-power density electron beam, it is difficult to secure related technologies. In this study, research was carried out to improve the machinability by developing the vaporized amplification sheets to realize the electron beam drilling technology. Their vaporized amplification sheets were analyzed by using the measurement of chemical and composition, which is such as TGA, SEM. We analyzed micro-hole processing using a microscope. Also, the thermal characteristics of vaporized amplification sheets are highly significant for applying to high-power density electron beam technique. So, we finished the vaporized amplification sheets according to the process conditions and analyzed it according to the machining conditions of the electron beam. It was confirmed that the effect on the experimental results differs depending on the influence of the metal powder contained in the developed material.