• 제목/요약/키워드: Resistance spot welding

검색결과 276건 처리시간 0.023초

DP60강의 인버터 DC 저항 용접의 용접 특성 및 기계적 성질에 관한 연구 (The Study on Inverter DC Resistance Spot Welding Character & Mechanical Property of DP60 Steels)

  • 김인주
    • 한국산학기술학회:학술대회논문집
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    • 한국산학기술학회 2011년도 추계학술논문집 2부
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    • pp.604-606
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    • 2011
  • Purpose This study analyzes resistance spot weldability of DP60 steels. Methodology To compare the resistance spot weldability of DP60 steels, tensile strength test and macro-section test were conducted for the resistance spot welds. Acceptable welding conditions were determined as a function of the resistance spot welding process parameters such as electrode force, welding time, and welding current. The lower limit of the welding lobe was the minimum shear tension strength for 590MPa-grade steel while the upper limit was determined whether or not expulsion was detected. Findings Welding force is 200kgf more appropriate in terms of 300kgf the larger the width of the welding zone. Acceptable welding current condition and welding lobe were changed depending on welding force. Research limitations This study is forced on inverter DC resistance spot weldability of 590Mpa-grade steels for automotive application. Practical implications This study confirms the weldability of DP60 steel by comparing resistance spot weldability depending on welding force. Originality This study analysed resistance spot weldability depending on welding force. wedability of DP60 steel were determined by welding lobes.

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레이저 점 용접의 응용 (Application of laser spot welding)

  • 양영수;정일;서정;한유희
    • 한국정밀공학회지
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    • 제14권3호
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    • pp.41-49
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    • 1997
  • Laser spot welding offers a unique combination of high speed. precision and low heat distortion, compared with conventional resistance spot welding. This combinatin of advantages is especially attractive for the automotive industry. Until now automobile fabrication is widely used resistance spot welding, however, because of geometric and structural problem, spot welding is required many welding machine in that reason by substituting spot welding with laser welding, it save the equipment cost. In the present study we measured ultimate strength and observed bead cross section of laser welded specimen and compared with that of the resistance spot welding results in order to adapt laser welding in automobile industry. Also for strength esti- mation we calculated the residual stress of laser welded zone. All calculations are performed with the ABAQUS code on a workstation.

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알루미늄 합금의 저항점 용접에 관한 연구 ( I ) (A Study on the Resistance Spot Welding of Aluminum Alloy (I))

  • 김상필;홍태민;장희석
    • Journal of Welding and Joining
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    • 제12권4호
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    • pp.127-140
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    • 1994
  • Resistance spot welding has been widely used in the sheet metal joining processes because of its high productivity and convenience. In the resistance spot welding processes the size of molten nugget is a criterion to assess weld quality. Many research have founded on measuring weld nugget size at the same time monitoring welding process parameters such as dynamic resistance and electrode movement. With increasing demand of energy saving, many efforts were made to employ aluminum alloys that are lighter than steel and have relatively equivalent strength to steel in the automobile industry. In this paper, spot weldability of aluminum alloys for various welding conditions were examined by series of experiments. One of the 6000 series (Mg-Si) aluminum alloy, 6383-T4 was chosen, which is currently considered as a substitute for the galvanized steel. Dynamic resistance, electrode movement and corresponding nugget size were observed and compared to the case of steel. Finally, resistance spot welding of dissimilar material (galvanized steel-aluminum alloy) was attempted.

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유전알고리즘을 이용한 인버터 DC 저항점용접에서의 정전류퍼지제어기 최적화 (Optimization of Fuzzy Controller for Constant Current of Inverter DC Resistance Spot Welding Using Genetic Algorithm)

  • 유지영;윤상만;이세헌
    • Journal of Welding and Joining
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    • 제28권5호
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    • pp.99-105
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    • 2010
  • Inverter DC resistance spot welding process has been very widely used for joining such as automotive body sheet metal. Because the lobe area of DC welding is larger than AC welding and DC welding has low electrode wear. So the use of Inverter DC resistance spot welding process has been further increased. And the application of high tensile steel is growing for light weight vehicle. To improve the weldability of high strength steel, the development of Inverter DC resistance spot welding system is more conducted. However, Inverter DC resistance spot welding system has a few problems. Current waveform is unstable and the expulsion has been occurred by characteristics of steel. In this study, inverter DC resistance spot welding system was made. And Fuzzy control algorithm was applied for constant current. The genetic algorithm was applied to optimize the fuzzy scaling factors, in order to optimize the fuzzy control.

구리와 알루미늄 이종금속 판재간의 전기저항가열 표면마찰 스폿용접 특성 (Characteristics of Electric Resistance Heated Surface Friction Spot Welding Process of Copper and Aluminum Dissimilar Metal Sheets)

  • 순샤오광;진인태
    • 한국기계가공학회지
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    • 제21권8호
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    • pp.99-109
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    • 2022
  • In this study, an electric resistance-heated surface friction spot-welding process was proposed and tested for the spot-welding ability of copper and aluminum dissimilar metal sheets using electric resistance heating and surface friction heating. This process has welding variables, such as the current value, energizing cycles, rotational speed, and friction time. The current value and energizing cycle can affect the resistance heat, and the rotational speed of the rotating pin and friction time influence frictional heat generation. Resistance heating before friction heating has a preheating effect on the Cu-Al contact interface and a positive effect on preventing friction heat loss during the friction stage. However, because resistance preheating can soften the copper sheet and affect the contact stress and friction coefficient, it has difficulties that may adversely affect frictional heat generation. Therefore, the optimal combination of welding variables should be determined through simulations and experiments of the spot-welding process to determine the effects of electric resistance preheating on the suggested process. Through this procedure, it is known that the proposed spot-welding process can improve the welding quality during the spot welding of Cu-Al sheets.

중첩된 알루미늄 5052 합금판재의 전기저항가열 마찰교반점용접에 관한 연구 (Electric Resistance Heated Friction Stir Spot Welding of Overlapped Al5052 Alloy Sheets)

  • 김태현;장민수;진인태
    • 소성∙가공
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    • 제24권4호
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    • pp.256-263
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    • 2015
  • Electric resistance spot welding has been used to join overlapped steel sheets in automotive bodies. Recently to reduce weight in automotive vehicles, non-ferrous metals are being used or considered in car bodies for hoods, trunk lids, doors parts, etc. Various welding processes such as laser welding, self-piercing rivet, friction stir welding are being used. In the current study, a new electric resistance heated friction stir spot welding is suggested for the spot welding of non-ferrous metals. The welding method can be characterized by three uses of heat -- electric resistance heating, friction stir heating and conduction heating of steel electrodes -- for the fusion joining at the interfacial zone between the two sheets. The welding process has variables such as welding current, diameter of the steel electrodes, revolutions per minute (rpm) of the friction stir pin, and the insert depth of the stir pin. In order to obtain the optimal welding variables, which provide the best welding strength, many experiments were conducted. From the experiments, it was found that the welding strength could be reached to the required production value by using an electrode diameter of 10mm, a current of 7.6kA, a stirring speed of 400rpm, and an insert depth of 0.8mm for the electric resistance heated friction stir spot welding of 5052 aluminum 1.5mm sheets.

자동차 새시용 DP60강 인버터 DC 저항 점용접의 용접성 평가 (Evaluation of Weldability on the Resistance Spot Welding of DP60 Steels for Automotive Chassis)

  • 김인주;오익현
    • 한국기계기술학회지
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    • 제13권4호
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    • pp.143-148
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    • 2011
  • This study analyzes the resistance spot weldability of DP60 steels. To analyze the resistance spot weldability of DP60 steels, tensile strength test and macro-section test were conducted for the resistance spot welds. Acceptable welding conditions were determined as a function of the resistance spot welding process parameters such as electrode force, welding time, and welding current. The lower limit of the welding lobe was the minimum shear tension strength for 590MPa-grade steel while the upper limit was determined whether or not expulsion was detected.

Process Tape를 사용한 마그네슘 합금의 저항 점 용접 특성 (Resistance Spot Welding Characteristics of Mg Alloy Using Process Tape)

  • 최동순;김동철;강문진
    • Journal of Welding and Joining
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    • 제31권3호
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    • pp.49-53
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    • 2013
  • Recently, studies about application of magnesium alloy sheet to automotive bodies are on the increase. For application to automotive bodies, researches about characteristics of resistance spot welding of magnesium alloy sheet are essential. Electrode life of resistance spot welding of magnesium alloy is very short due to sticking of magnesium alloy to copper alloy electrode. To increase electrode life, most effective method is inserting cover plate between electrode and magnesium sheet. But application of cover plate to actual process is difficult and decreases welding productivity. Process tape supplied automatically as cover plate can minimize lose of productivity and increase welding quality. In this study, resistance spot welding of magnesium alloy is carried out with applying process tape. Acceptable welding current region according to electrode force and welding time is determined.

돔형 전극을 사용한 마그네슘 합금 저항 점용접의 전극 수명 평가 (Electrode Life Test of Resistance Spot Welding on Mg Alloy Using Dome Type Electrode)

  • 최동순;황인성;김동철;강문진
    • Journal of Welding and Joining
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    • 제31권6호
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    • pp.27-31
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    • 2013
  • Magnesium alloy is used on parts of aircraft and electronic equipment because of the highest specific strength among the common metal materials. Recently, studies about appling magnesium alloy sheet to automotive bodies are on the increase rapidly. For application to automotive bodies, researches about characteristics of resistance spot welding of magnesium alloy sheet are essential. Magnesium alloy has low boiling point, so getting sound bead shape is difficult when appling varies welding processes. Resistance spot welding is also particular about setting optimum welding conditions because of spatter generation, pores and cracks occurrence in nugget. And life of electrodes is very short because of alloying with copper that main material of electrodes. This requires frequent dressing and replacement of electrodes and decrease in productivity of resistance spot welding on magnesium alloy. Therefore in this study, for effective analysis of changes in tensile shear load and nugget size during electrode life test, evaluate detail characteristics of resistance spot welding on magnesium alloy sheet using dome type electrode.

음향방출을 이용한 저항 점용접의 용접 품질평가 (Quality Evaluation of Resistance Spot Welding using Acoustic Emission)

  • 조대희;이장규;박성완;조진호;김봉각;우창기
    • 한국공작기계학회논문집
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    • 제15권4호
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    • pp.98-104
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    • 2006
  • In this paper, for the purpose of investigation the acoustic emission(AE) behaviors during resistance spot welding process and tension test of spec steels. As the results present the resistance spot welding method that can get suitable welding qualities or structural integrity estimating method. The resistance spot welding process consists of several stages: set-down of the electrodes; squeeze; current flow; forging; hold time; and lift-off. Various types of AE signals are produced during each of these stages. For tensile-shear test and cross tensile test in resistance spot welded specimens, fracture pa 야 ems are produced: tear fracture; shear fracture; and plug fracture. Tensile-shear specimens strength appeared higher than cross tensile specimens one. In case of tensile-shear specimen happened tear fracture that crack happens in most lower plate. Also, in case of cross tensile specimens, upper plate and lower plate are detached perfect fracture was exposed increases a little as acting force is lower than ordinary welding condition. Therefore, the structure which is combined by resistance spot welding confirmed that welding design must attain so that shear stress may can interact mainly.