• Title/Summary/Keyword: Weld-Line Part

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Welding process for manufacturing of Nuclear power main components (원자력 발전 주기기 제작에 적용되는 용접공정)

  • Jung, In-Chul;Kim, Yong-Jae;Shim, Deog-Nam
    • Proceedings of the KWS Conference
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    • 2010.05a
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    • pp.43-46
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    • 2010
  • As the nuclear power plant has been constructed continuously for several decades in Korea, the welding technology for components manufacturing and installation has been improved largely. Standardization for weld test and qualification was also established systematically according to the concerned code. The welding for the main components requires the high reliability to keep the constant quality level, which means the repeatability of weld quality. Therefore the weld process qualified by thorough test and evaluation is able to be applied for manufacturing. Narrow gap SAW and GTAW process are usually applied for girth seam welding of pressure vessel like Reactor vessel, steam generator, and etc. For the surface cladding with stainless steel and Inconel material, strip welding process is mainly used. Inside cladding of nozzles is additionally applied with Hot wire GTAW and semi-auto welding process. Especially the weld joint having elliptical weld line on curved surface needs a specialized weld system which is automatically rotating with adjusting position of the head torch. The small sized pipe, tube, and internal parts of reactor vessel requests precise weld processes like an automatic GTAW and electron beam welding. Welding of dissimilar materials including Inconel690 material has high possibility of weld defects like a lack of fusion, various types of crack. To avoid these kinds of problem, optimum weld parameters and sequence should be set up through the many tests. As the life extension of nuclear power plant is general trend, weld technologies having higher reliability is required gradually. More development of specialized welding systems, weld part analysis and evaluation, and life prediction for main components should be taken into a consideration extensively.

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Effect of Initial (Reference) Welding Current for Adaptive Control and It's Optimization to Secure Proper Weld Properties in Resistance Spot Welding

  • Ashadudzzaman, Md.;Choi, Il-Dong;Kim, Jae-Won;Nam, Dae-Geun;Park, Yeong-Do
    • Journal of Welding and Joining
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    • v.33 no.6
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    • pp.13-20
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    • 2015
  • Many automotive companies are endeavoring to improve the quality of resistance spot welding by updating body-in-white (BIW) production line with adaptive control spot welding system to compensate the process disturbances such as gap, electrode wear, oxidized surfaces, poor fit up and adhesive etc. Most of the commercial adaptive weld controllers require proper "Initial Welding Schedule" or "Reference weld" to achieve compensation in welding parameters during real time welding. In this study, the compensation of a commercial adaptive weld controller had been observed and analyzed thoroughly for various process disturbances to find optimal initial welding schedule. It was observed that 90 percent of the expulsion current in constant current control as reference welding schedule conferred the maximum button diameter in adaptive control welding. Finally, effects of each disturbance in combined field disturbances system with adaptive control had also been confirmed with the design of experiment (DOE) by minitab(R)16 for combined disturbances situation and suitability of optimum initial weld current had also established with real body part validation test.

δ-Ferrite Behavior of Butt Weld Zone in Clad Steel Plates Depended on Holding Time of PWHT (클래드강 맞대기 용접부의 후열처리 유지시간에 따른 델타 페라이트 거동)

  • Park, Jae-Won;Lee, Chul-Ku
    • Journal of Welding and Joining
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    • v.32 no.2
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    • pp.29-36
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    • 2014
  • Recently, in order to enhance the function and usefulness of products, cladding of dissimilar materials that maximizes the performance of the material is being widely used in all areas of industry as an important process. Clad steel plate, produced by cladding stainless steel plate, an anticorrosive material, on carbon steel plate, is being used to produce pressure vessels. Stainless steel plate has good corrosion resistance, and carbon steel plate has good rigidity and strength; clad steel can satisfy all of these qualities at once. This study aims to find the ${\delta}$-ferrite behavior, mechanical properties, structure change, integrity and reliability of clad steel weld on hot rolled steel plates. For this purpose, multi-layer welding, repair welding and post weld heat treatment were implemented according to welding procedure specifications (WPS). In order to observe the mechanical properties and toughness of clad steel weld zone, post weld heat treatment was carried out according to ASME Sec. VIII Div.1 UW-40 procedure for post weld heat treatment. With heat treatment at $625^{\circ}C$, the hold time was used as the process variable, increased by intervals that were doubled each time, from 80 to 1,280 min. The structure of weld part was typical cast structure; localized primary austenite areas appeared near central vermicular ferrite and fusion line. The heat affected zone showed rough austenite structure created by the weld heat input. Due to annealing effects of heat treatment, the mechanical properties (tensile strength, hardness, impact value) of the heat affected area tended to decrease. From the results of this study, it is possible to conclude the integrity of clad steel welds is not affected much in field welding, repair welding, multi-layer welding, post weld heat treatment, etc.

Integrated Operating System For Welding Automation on Assembly Line At Shipyards (대조립 블럭 용접 자동화를 위한 통합 운영 시스템)

  • Kim, Byung-Su;Rhee, Si-Youl;Kim, Eun-Jung;Park, Jin-Hyung;Park, Young-Jun
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.1752-1756
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    • 2003
  • Welding automation in shipbuilding process, especially in the assembly line is considered to be a difficult job because welding part is too huge , various and unstructured for a welding robot to weld the whole part automatically. We developed an automatic welding robot to improve those difficult process. This paper show how to systematically operate the integrated automation system which consists of several robots. We introduce our software and system integration method. Specially we focus that network communication and operating process. The developed system visualizes the operation environment using Open Inventor and communicates with the entire system via TCP/IP and FTP.

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The Application of 3D Injection Molding Simulation in Gate Location Selection for Automotive Console (자동차용 콘솔 게이트 위치 선정을 위한 3차원 사출성형 시뮬레이션 활용)

  • Choi, Young-Geun
    • Journal of Power System Engineering
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    • v.18 no.3
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    • pp.51-58
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    • 2014
  • Injection molding simulation provided optimized design results by analyzing quality problems while the product is in assembly or in the process of manufacturing with make automobile plastics. Frequent change of design, change of injection molding, repetition of test injection which was held in the old way can now be stopped. And quality upgrade is expected instead. This report deals with the effect which the position of injection molding automobile console gate and number has on product quality including pressure at end of fill, bulk temperature at end of fill, shear stress of end of fill, residual stress at post filling end, product weld lines and warpage results. Simpoe-Mold simulates the complete manufacturing process of plastic injected parts, from filling to warpage. Simpoe-Mold users, whether they are product designers, mold makers or part manufacturers, can identify early into the design stage potential manufacturing problems, study alternative solutions and directly assess the impact of such part modification, whatever the complexity and geometry of such parts, shell part as plain solid parts.

Analysis of Relationship between the Irregularities of Rail Weld Surface and Track Irregularities (레일용접부 요철과 궤도틀림 상관관계 분석)

  • Woo, Byoung-Koo;Kim, Yong-Hyok;Yun, Un-San;Kim, Kwan-Hyung;Lee, Sung-Uk
    • Proceedings of the KSR Conference
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    • 2009.05a
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    • pp.539-545
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    • 2009
  • KTX trains which began passenger service between Seoul and Busan in April 2004 have gained very high evaluation for their safe operation. Track is one of the most important means to keep KTX safety, it has not been a fail of safe structure. The track failure during operation may lead to a severe accident. So, it is to be verified the confidence of track maintenance management on the high speed line. This paper would like to find a track deformation trend through a comparative analysis on actual measurement data at these times. It discusses the effect of cyclic dynamic load at welding part. KTX dynamic impact load was measured in accordance with a rail surface irregularity and analyzed some track irregularities according to the condition of rail profile at welding part in the Gyeongbu high speed line.

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Fiber Orientation of Short Fiber Reinforced Polymeric Composites Depending on Injection Mold Shape Variations (단섬유강화 고분자 복합재료에서 사출성형 형상금형 형상변화에 따른 섬유배향상태)

  • Kim, Hyuk;Han, Gil-Young;Lee, Dong-Gi
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.778-784
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    • 2001
  • Injection molding is a very important industrial process for the manufacturing of plastics objects. During an injection molding process of composites, the fiber-matrix separation and fiber orientation are caused by the flow of molten polymer/fiber mixture. As a result, the product tends to be nonhomogeneous and anisotropic. Hence, it is very important to clarify the relations between separation orientation and injection molding conditions. So far, there is no research on the measurement of fiber orientation using image processing. In this study, the effects of fiber content ratio and molding condition on the fiber orientation-angle distributions are studied experimentally. Using the image processing method, the fiber orientation distribution of weld-line parts in injection-molded products is assessed. And the effects of fiber content and injection molding conditions on the fiber orientation functions are also discussed.

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A STUDY OF WARPAGE IN ONE WAY LONG PARTS (한 방향으로 긴 제품에 대한 변형연구)

  • Kim, Jong-Kab;Cho, Chae-Sung;Park, Sang-Deuck
    • Proceedings of the KSME Conference
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    • 2000.04a
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    • pp.741-744
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    • 2000
  • In general there occur warpage in one way long part. Warpage is caused by differential shrinkage-Orientation Effect, Volumetric Shrinkage Effect, Differential Cooling Effect -over the part. Deco-Top is located at the top of 29"TV set and it's shape is one way long$(626{\times}130mm)$. Material is used transparency ABS resin. So we can't design ribs in this part. And we use film gate to avoid weld line. In these reasons we must develop no ribs and no warpage product. In this study we use MOLDFLOW's software-MF/FLOW, MF/COOL, MF/WARP. Using MF/FLOW, set the flow balance and gate positioning. And we can set cooling channel layout and the optimum processing condition through MF/COOL and MF/WARP. In result we reduced trials and obtained good product.

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A Study on Gas-Assisted Plastic Injection Mould of Flat TV Front Cover (Flat TV Front Cover Gas 사출 금형에 대한 연구)

  • 문영대
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2003.10a
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    • pp.201-206
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    • 2003
  • Plastic injection mould have two kinds of trouble, one is in mould another in injection parts. Most of defects of the former take the cause in a design like in structure and working, the later weld line, transforming, sink mark, burning, flow mark, scratching, shading, black hole and so on. Most of problems of the later is difficult for making a clear definitely the reason of defects because of complexible. The purpose of this paper is to improve the quality of plastic injection mould and parts with inquiring the counter plan and rouble of the part of Flat TV Front Cover by flow control method and gas- assisted injection moulding. For minimizing defects from injection moulding parts, this paper was investigated with using computer aided injection mold filling simulations. Based on these numerical results, I established guidelines mould design and injection processing condition. As a results I got the improve of quality, minimizing surface defects moulded parts and troubles in mould.

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A Study on the Effects of Filling and Packing Phases on the Injection Modeling (사출성형에 대한 충전과 보압과정의 영향에 관한 연구)

  • 김현필;김용조
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2002.04a
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    • pp.112-118
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    • 2002
  • Injection molding process factors such as molding temperature, injection pressure, flow rate and flow velocity, must be controlled properly in filling and packing phases in the injection molding process. In this study, effects of these factors on the injection molding were investigated through the flow analysis fur the filling and packing phases. Molding troubles like flow mark, weld line, sink mark, short shot and warpage can be caused by these injection molding process factors. Among them, the short shot was caused by that the packing pressure could not reach properly to the filling end part in the packing phase and hence the flow rate could not be supplied to the full. In addition, as the flow rate for the volumetric shrinkage during the frozen phase could not be supplied properly by the packing pressure, the short shot appeared. Here, the volumetric shrinkage reduced with increasing the packing pressure and also the warpage of molded part increased with increasing the packing pressure.

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