• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2006년 추계학술발표대회 개요집
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• pp.48-50
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• 2006

Recently many research are going on in the field of application of Laser-Arc hybrid welding for superstructures such as ship-structures, transport vehicles etc. however, the study on heat distribution and welding residual stress of hybrid weld by numerical simulation leaves much to be desired. Therefore a Finite Element based numerical comparison of heat distribution and thermal history in both the FCAW and Hybrid welding been made in this study. Based on this thermal outputs from the present model could be sequentially coupled to suitable mechanical models to predict appropriate mechanical characteristics such as residual stress.

• Journal of Welding and Joining
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• 제14권3호
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• pp.75-85
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• 1996

In this paper the influence of postweld heat treatment on mechanical properties of SMAW and FCAW stainless steel weldments was examined and the obtained results are as follows ; (1) The amount of $\delta$-ferrite formed by SMAW and FCAW process decreased with increasing holding temperature and time in post weld heat treatment(PWHT), and it was found that the reduced ferrite was transformed into sigma phase after $800^{circ}C{\times}50hr$ PWHT. This sigma phase, even though it was very small, resulted in brittleness of dissimilar weldment between carbon steel and stainless steel in bending test, however in similar weldment between stainless steel and stainless steel was not occured. (2) The chemical composition of sigma phase was measured to 28-30%Cr, 7-9%Mo, 4-6Ni in 316L weldment, and also 35-37%Cr, 0.9-1.0Mo, 6-8%Ni in 309L weldment by EDS analysis.

• Journal of Welding and Joining
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• 제26권2호
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• pp.69-74
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• 2008

590MPa grade weldable steels were gas metal arc welded with flux cored wires. Welding parameters such as current, voltage, and speed were varied independently. Effects of each parameter on the strength and chemical composition of weld metal were investigated. Increase of voltage caused decrease of weld metal tensile strength due to the low recovery of alloying elements such as carbon and manganese. On the contrary, increase of current and speed resulted in increase of weld metal strength because of higher recovery of the alloying elements.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2007년 추계학술발표대회 개요집
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• pp.45-47
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• 2007

주강소재 보수용접부의 품질 및 용접생산성 향상을 위해 기존 용접후열처리 조건(이하 PWHT)을 모재에 적용하는 품질열처리(이하 NTT)로의 대체 및 반자동 FCAW 용접방법의 적용 가능성을 확인하기 위해 상온 및 고온 물성평가(고온인장강도, 크리프 파단강도)를 수행한 결과, 제작 공정 측면에서 FCAW의 적용이 가능한 것으로 확인되었다. 또한 PWHT 대신 NTT를 적용함으로서 용접방법별 물성 편차가 줄어드는 NTT 열처리의 긍정적 효과가 확인되어, 궁극적으로 기존 PWHT 및 NTT 모두 적용이 가능한 것으로 확인되었다.

• 한국산학기술학회논문지
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• 제6권2호
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• pp.122-128
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• 2005

본 연구에서는 구조용강 SM520을 사용하여 교량용 박스 제작시 플럭스 코어드 아크용접법에서 가스실드방식과 셀프실드방식의 두 공정으로 제작된 용접부를 건전성, 기계적 성질 및 미세조직에서 비교하였다. 그 결과 두 용접 프로세스에 의해 제작된 용접부들은 매크로 조직 및 비파괴 검사 결과 건전성이 입증되었고, 항복 및 인장강도가 각각 $462{\sim}549\;MPa$와 $548{\sim}640\;MPa$였고, CVN 충격치는 $-20^{\circ}C$에서 요구값인 40J을 충족하였다. 결과적으로, 고속철도나 고속도로 건설시 사용되는 교량용 SM520강 박스 제조시 고소 및 강풍 조건하에서 용접할 때 셀프실드 아크용접법은 기존의 가스실드 아크 용접법과 비교하여 대등한 용접 특성들을 보였기 때문에 현장 시공시 적용 타당성이 있다고 사료된다.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2004년도 추계학술발표대회 개요집
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• pp.202-204
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• 2004

The purpose of this study is to evaluate the effects of welding conditions on the shape of arc of FCAW using high speed camera system. Length and deflection of arc were evaluated from images of arc which were transformed by threshold processing. Based on the experimental results, a regression model for the length of arc was established. A major factor affecting deflection of arc was the length of arc.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1994년도 특별강연 및 추계학술발표 개요집
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• pp.134-137
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• 1994

In this study, The mean weld current is used to correct depth direction, and weight-value, specially devised to check right-left deviation by placing more weight on the left- and right-most part of weld current during weaving, to correct weaving direction. The methodology of “design of experiments” was introduced to find out dorminant weld parameters affecting these for values.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2005년도 춘계학술발표대회 개요집
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• pp.69-70
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• 2005

In order to prevent the arc blow at the FCA welding system with multi-torches, the effects of arc length on the magnetic flux at the FCA weldment was evaluated using electro-magnetic filed analysis. Magnetic flux density around arc are slightly increased with an increase in the arc length. Based on the FEA results, the minimum distance of torches to control arc blow was established.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2005년도 춘계학술발표대회 개요집
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• pp.118-120
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• 2005

대형구조물 제작 시에는 세라믹백킹재 등 백킹재를 이용한 편면용접법이 많이 채용되고 있다. 이처럼 백가우징이 적용되지 않는 편면용접법으로 용접 시공 시, 표면부에 비해 루트부의 충격성능이 열화되는 경향이 있다. 본 연구에서는 세라믹백킹재를 채용한 편면용접법의 루트부의 저온 충격성능을 확보할 수 있는 용착금속의 Ni 함량에 대해 고찰하고자 한다.

• Journal of Welding and Joining
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• 제1권2호
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• pp.76-82
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• 1983

The chemical composition of deposit metal by flux cored arc welding can be easily regulated though addition of deoxidizers and alloying elements in cored flux and fluxes of flux coored wire arc analogous to those of coated electrode. It is necessary to investigate the transfer and yield efficiency due to addition of necessary alloy elements in deposit metal. This report is made to intorduce an experimental equation from the relation between welding condition and extent of penetration, deposit metal and weld melt slag and to estimate transfer and yield efficiency of alloy components in fluxes through chemical analysis of deposit metal.