• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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• pp.430-432
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• 2002

Some confusion in the terminology concerning the weld quality and its assurance seems caused by the different practises currently in use around the world. Qualified welding personnel are not automatically certified personnel. Education and training are the tools to obtain qualification. Flexibility in training and education seems logical and the most cost-effective way to obtain qualified personnel. A third party seems essential for issuing recognised Certificates. Manufacturers of welded products continue to face increased demands and concerns regarding weld quality. The following are the main conditions influencing weld quality: $\bigcirc$ Establishing reliable productions procedures and tests that meet the requirements of established codes and standards. $\bigcirc$ Finding qualified welding personnel capable of reliably carrying out established welding procedures. The issue of hiring and keeping skilled welding personnel has been a crucial consideration for manufacturers worldwide for the past few decades. It will continue to be a concern for decades to come.

• International Journal of Advanced Culture Technology
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• 제3권1호
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• pp.179-187
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• 2015

This study presents the experimental results of the Friction Stir Welding (FSW) of AA6063 aluminum alloy and AISI304 stainless steel butt joint by varying the welding parameters such as the rotating speed and the welding speed. The main results are as follows. The variation of the welding parameters produced various characteristic interfaces and had distinct influences on the joint properties. Increasing the rotating speed and the welding speed decreased the joint tensile strength because it produced the defect on the joint interface. The optimum welding parameter that could produce the sound joint was a rotating speed of 750 rpm and the welding speed of 102 mm/min with the tensile strength of 71 MPa.

• Journal of Welding and Joining
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• 제24권5호
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• pp.67-73
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• 2006

Laser welding is suitable for welding to the aluminum alloy sheet. In order to apply the aluminum laser welding to production line, parameters should be optimized. In this study, the optimal welding condition was searched through the genetic algorithm in laser welding of AA5182 sheet with AA5356 filler wire. Second-order polynomial regression model to estimate the tensile strength model was developed using the laser power, welding speed and wire feed rate. Fitness function for showing the performance index was defined using the tensile strength, wire feed rate and welding speed which represent the weldability, product cost and productivity, respectively. The genetic algorithm searched the optimal welding condition that the wire feed rate was 2.7 m/min, the laser power was 4 kW and the welding speed was 7.95 m/min. At this welding condition, fitness function value was 137.1 and the estimated tensile strength was 282.2 $N/mm^2$.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2010년도 춘계학술발표대회 초록집
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• pp.72-72
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• 2010

최근 오일샌드, 극지유전, 심해저자원 등 극한지 자원개발이 활발해짐에 따라 수요가 증대되고 있는 극한지용 내마식 소재는 내마식성과 함께 저온 인성이 요구된다. 철계 합금에서 관찰되는 변형유기 마르텐사이트 상변태는 입자의 충돌에 의한 충격을 흡수하고 소재의 표면을 가공경화시켜 내마식성 향상 및 저온 인성에 기여할 수 있을 것으로 기대되고 있지만 합금조성의 정교한 제어가 필요하기 때문에 오버레이 용접에 적용하기 위해서는 모재와의 희석률을 제어하는 방안이 필요하다. 용접플럭스 설계기술은 용접시 금속이행모드, 용융지 유동거동 등과 같은 용접현상 제어를 통해 오버레이 용접재료의 용접성과 용접부 희석률을 최적화할 수 있는 기술이다. 본 연구에서는 내마식 고인성 오버레이 용접재료의 개발을 위해 Fe-12Cr-1.2C 합금조성을 갖는 메탈코어드 와이어에 대하여 아크안정제로 사용되는 Ca 함유 용접플럭스 첨가가 용착부 형상 및 희석률 변화에 미치는 영향을 조사하였다.

• 대한공업교육학회지
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• 제33권1호
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• pp.282-296
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• 2008

기존의 자동차 부품 로봇 용접방법은 노즐을 통하여 $CO_2$ 가스가 확산되는 구조로 되어있어 용접대상물에 노즐간섭으로 인하여 로봇 용접이 불가능한 부위가 많고, 공간이 좁은 부분의 용접은 2차 수작업으로 완성하고 있어 생산성 향상에 걸림돌이었다. 따라서 본 연구에서는 이러한 용접과정을 분석하여 $CO_2$ 가스 소모량을 절약하고, 좁은 공간 부위를 로봇 용접할 수 있는 새로운 특수 용접 노즐을 개발하여 생산성을 향상시키고자 하였다. 본 연구개발에서 설계 제작된 협대역 자동차 부품 로봇 용접용 특수 용접 팁은 2단 구조로서 중단부에 직경 3mm의 구멍을 8개소로 제작하고 $CO_2$ 가스 소모량을 47%이상 절약한 형태로서 용접 결함율이 비교적 낮은 개발품이다. 본 연구의 결과는 국내 자동차 업계에서 사용되는 구형 용접 팁을 중간부에 구멍이 뚫린 2단 구조의 노즐로 대체하면 생산원가를 절감할 수 있다고 판단된다.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2009년 추계학술발표대회
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• pp.33-33
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• 2009

This study is to develop the resistance welding apparatus and investigate the welding characteristics of Zircaloy-4 end-plate of fuel bundle in the cases of the resistance welding and the laser beam welding. The welding parameters which affect the weld nugget and the torque values have been also compared. The effect of the torque strength of end-plate welding using by the resistance welding and the laser beam welding has been studied and optimum conditions of Zircaloy-4 end-plate welding have been found. Futhermore, micro-structures and micro-hardness of the resistance welded specimens have been also compared.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2011년도 춘계학술논문집 2부
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• pp.683-686
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• 2011

The effect of welding material such as welding wires and materials for contact tip on the contact tip wear was investigated. Two types welding wires such as solid and flux cored wire and a variety of contact tips made of Cu-P, Cu-Cr(0.25%), Cu-Cr(1%) and Cu-Cr-Zr were employed for the comparison of wear resistance. It was found that the wear resistance of contact tips materials was Cu-Cr-Zr, Cu-Cr(1%), Cu-Cr(0.25%), Cu-P in order while the solid wire had a better wear resistance than flux cored wire.

• 한국산업보건학회지
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• 제34권2호
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• pp.156-165
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• 2024

Objectives: This study aims to identify and analyze the exposure status of welding students in specialized high school welding labratories, compare it with the exposure to welding hazards of industrial workers, and seek to improve the educational environment for youth through domestic and international exposure standards. Methods: This study compares the level of exposure to hazardous factors in a welding laboratory of a vocational high school in Jeollanam-do and a welding process in a general industrial site by measuring the work environment. A 10-question survey was conducted to review the effects of welding hazards on the human body, carcinogenicity information, international (US, UK, France) exposure standards, general characteristics between the two groups, and awareness of occupational health. Results: Exposure to hazardous factors in both groups was below the standards set by MOEL. Specialized high school students were exposed to higher levels than workers, and some hazardous factors exceeded the standards when compared to international exposure standards. During the survey, students were less aware of the hazards of welding, safety and health education, and the need for work environment measurement than workers. Conclusions: For the respiratory protection of students in vocational high school welding labs, it is necessary to create a comfortable training environment. Exposure standards for harmful factors should be strictly applied, such as overseas standards, or exposure should be limited by setting a limit on the number of hours of welding practice per week. In addition, it is necessary to conduct safety and health education for welding students to raise their awareness of the importance of measuring the working environment and wearing appropriate protective equipment.

• 한국산학기술학회논문지
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• 제12권5호
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• pp.2019-2024
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• 2011

GMA용접 공정에서 콘택트팁의 마모가 용접비드에 미치는 영향에 대해서 연구하였다. 콘택트팁과 용접비드 사이의 연관성을 조사하기 위하여 초고속 카메라와 파형분석을 이용하여 용적이행을 관찰하였고, 저 배율의 카메라로 비드의 상태를 관찰하였다. 콘택드팁의 마모는 팁과 용접와이어 사이의 접촉 지점을 변화시켜 결과적으로 불규칙비드를 생성하였다. 이것은 마모된 콘택트팁이 용접시 용접저항의 변화를 초래하여 용접아크 불안정의 원인이 되기 때문이다.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2003년도 춘계학술발표대회 개요집
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• pp.122-123
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• 2003