• Title/Summary/Keyword: Weld quality control

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A Study on Monitoring for Process Parameters Using Isotherm Radii (등온선 반경을 이용한 공정변수 모니터링에 관한 연구)

  • Kim, Ill-Soo;Chon, Kwang-Suk;Son, Joon-Sik;Seo, Joo-Hwan;Kim, Hak-Hyoung;Shim, Ji-Yeon
    • Journal of Welding and Joining
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    • v.24 no.5
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    • pp.37-42
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    • 2006
  • The robotic arc welding is widely employed in the fabrication industry fer increasing productivity and enhancing product quality by its high processing speed, accuracy and repeatability. Basically, the bead geometry plays an important role in determining the mechanical properties of the weld. So that it is very important to select the process variables for obtaining optimal bead geometry. In this paper, the possibilities of the Infrared camera in sensing and control of the bead geometry in the automated welding process are presented. Both bead width and thermal images from infrared thermography are effected by process parameters. Bead width and isotherm radii can be expressed in terms of process parameters(welding current and welding speed) using mathematical equations obtained by empirical analysis using infrared camera. A linear relationship exists between the isothermal radii producted during the welding process and bead width.

A Development of the Inference Algorithm for Bead Geometry in the GMA Welding Using Neuro-fuzzy Algorithm (Neuro-Fuzzy 기법을 이용한 GMA 용접의 비드 형상에 대한 기하학적 추론 알고리듬 개발)

  • Kim, Myun-Hee;Bae, Joon-Young;Lee, Sang-Ryong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.2
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    • pp.310-316
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    • 2003
  • One of the significant subject in the automatic arc welding is to establish control system of the welding parameters for controlling bead geometry as a criterion to evaluate the quality of arc welding. This paper proposes an inference algorithm for bead geometry in CMA Welding using Neuro-Fuzzy algorithm. The characteristic welding parameters are measured by the circuit composed of hall sensor, voltage divider tachometer, etc. and then the bead geometry of each weld pool is calculated and detected by an image processing with CCD camera and a measuring with microscope. The relationships between the characteristic welding parameters and the bead geometry have been arranged empirically. From the result of experiments, membership functions and fuzzy rules are tuned and determined by the learning of neural network, and then the relationship between actual bead geometry and inferred bead geometry are concluded by fuzzy logic controller. In the applied inference system of bead geometry using Neuro-Fuzzy algorithm, the inference error percent is within -5%∼+4% in case of bead width, -10%∼+10% in bead height, -5%∼+6% in bead area, -10%∼+10% in penetration. Use of the Neuro-Fuzzy algorithm allows the CMA Welding system to evaluate the quality in bead geometry in real time as the welding parameters change.

An Experimental Study on Prediction of Bead Geometry for GTA Multi-pass Welding in Underhead Position (GTA 아래보기 자세 다층용접부의 비드형상 예측에 관한 실험적 연구)

  • Park, Min-Ho;Kim, Ill-Soo;Lee, Ji-Hye;Lee, Jong-Pyo;Kim, Young-Su;Na, Sang-Oh
    • Journal of Welding and Joining
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    • v.32 no.1
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    • pp.53-60
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    • 2014
  • The automatic arc welding is generally accepted as the preferred joining technique and commonly chosen for assembly of large metal structures such as in areas of automotive, aircraft and shipbuilding due to its joint strength, reliability, and low cost compared to other joint processes. Recently, several mathematical models have been developed and studied for control and monitoring welding quality, productivity, microstructure and weld properties in arc welding processes. This study indicates the prediction of process parameters for the expected welding quality with accordance to the adaptive GTA welding process. Furthermore, the mathematical models is also develop to aid the selection of an optimal welding process as the generation of process controls to predict the bead geometry as a function output parameters in the GTA welding process. The developed models through this study showed comparatively excellent predicted results, and will extend to other welding processes to integrate an optimized system for the robotic welding process.

A New Algorithm for Control of Robotic Arc Welding Process (로봇 아크용접 공정제어를 위한 새로운 알고리즘)

  • Park, Yo-Chang;Kim, Il-Su;Park, Chang-Eon;Kim, Jung-Sik;Heo, Eop;Jung, Young-Jae
    • Proceedings of the KWS Conference
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    • 2001.05a
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    • pp.65-68
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    • 2001
  • The application of a feedback control system in robotic arc welding is becoming more and more demanding than ever before. This requirement arises from the fact that robotic arc welding process needs no manual operator to monitor and manipulate the process parameters and hence a means of controlling the quality of the robotic arc welding process becomes apparent. Arc force sensor employed in this research to monitor the bead geometry of the arc welding process, A relationship between the bead dimension and the arc force distributions was established. Experimental configuration for measurement of arc force was used to quantify the changes in the arc force distributions of the plate being welded. Arc force sensor mounted at the end of the robot wrist was employed to measure the arc force applied to the weld. The sensor information was the used to establish a relationship between welding current and arc force. Arc force sensor have shown to be on of the most sophisticated technique to monitor perturbations that occurred during arc welding process.

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A Study on the Mitigation of Welding Distortion of a Precision Component for Automobile Transmission (자동차 변속기용 정밀 부품의 용접변형 감소화에 관한 연구)

  • Chung, Hoi-Yoon;Kim, Jae-Woong;Yun, Seok-Chul
    • Journal of Welding and Joining
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    • v.30 no.4
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    • pp.31-37
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    • 2012
  • In recent years, a demand for precision-welding is increasing in wide industrial fields for getting a high quality welded structures. Although laser welding is commonly used for precision-welding, gas tungsten arc (GTA) welding is also attempted as a precision-welding due to the cost benefit. However, welding heat causes an uneven temperature distribution leading to welding deformation. Since it causes geometric errors and degrades product quality, welding distortion recently rises as an important issue in the field of automobile parts. To control welding deformation, it is needed to design in shapes that can maximize stiffness against deformation during welding; control the welding sequence; minimize heat input; and weld allowing reverse deformation; etc. Thus it is necessary to find the one, among such approaches, that can minimize the deformation range by mathematical analysis and understand how effective it would be when it is actually used in industrial fields. This study performs analyses by numerical calculations and experiments for the De-Tent Lever, one of transmission part that requires precision the most among automobile parts, as the subject of experiment. Decrease in welding deformation is required for this part, since there is currently a trouble in guaranteeing precision due to angular deformation by welding between boss and plate. Finally the ways to minimize welding deformation has been suggested in this study through analyses on it.

A Study on Development of Automatic Path Tracking Algorithm for LNG Aluminium Plate and Selection of Process Parameters by Using Artificial Intelligence (LNG 알루미늄 판재 가공용 자동 궤적 추적 알고리즘 개발 및 인공지능을 이용한 공정조건 선정에 관한 연구)

  • 문형순;권봉재;정문영;신상룡
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.8
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    • pp.17-25
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    • 1998
  • Aluminum alloys have low density, relatively high strength and yield strength, good plasticity, good machinability, and high corrosion and acid resistance. Therefore, they are suitable for large containers for the food, chemical and other industries. Large containers are often bodies of revolution consisting of shell courses, stiffening rings, heads and other elements joined by annular welds. Larger containers have longer welds and require greater leak-tightness and higher weld mechanical properties. The LNG tank consists of aluminum plates with various sizes, so its construction should by divided by several sections. Moreover, each section has its own sub-section consisted of several aluminum plates. To guarantee the quality of huge LNG tank, therefore, the precise control of plate dimension should by urgently needed in conjunction with the appropriate selection of process parameters such as cutting speed, depth of cut, rotational speed and so on. In this paper, a manufacturing system was developed to implement automatic circular tracking in height direction and automatic circular interpolation in depth of cut direction. Also, the neural network based on the backpropagation algorithm was used to predict the cutting quality and motor load related with the life time of the developed system. It was revealed that the manufacturing system and the neural network could be effectively applied to the bevelling process and to predict the quality of machined area and the motor load.

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A study on gas vent control of injection mold for the production of precision medical device parts (정밀 의료기기 부품 생산을 위한 사출금형의 가스벤트 제어에 관한 연구)

  • Lee, Jeong-Won;Son, Min-Kyu
    • Design & Manufacturing
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    • v.14 no.2
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    • pp.34-41
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    • 2020
  • Typical characteristics of medical device parts are that they can not be reused and there are many disposable products. Therefore, there is a need for an injection molding machine having excellent repeatability of molding conditions and a precision injection mold for mass production. Recently, the performance of an injection machine has made a remarkable evolution compared to the past. However, defects such as short-shot, flash, weld line, gas burning, warpage, and deformation, which are typical defects, still do not disappear at all. This is due to the lack of gas ventilation from the product cavities, even if the gas is smoothly vented from the sprue and runner of the mold. For this reason, the internal pressure of the cavity rises and is directly connected to the quality defects. In this study, an active gas vent system was designed to prevent defects due to trapped gas in the cavity. Since it can be easily adjustable in response to the molding conditions and the mold temperature changes, it is expected to improve productivity due to the reduction of the defective ratio.

An Experimental Study on Root-pass Welding of Open Gap by GMA Welding Process in Pipeline (GMA 용접공정을 이용한 오픈갭 수평고정관 초층 용접의 실험적 연구)

  • Kim, Ji-Sun;Kim, Ill-Soo;Park, Chang-Eun;Na, Hyun-Ho;Lee, Ji-Hye;Jung, Seong-Myeong
    • Journal of Welding and Joining
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    • v.29 no.3
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    • pp.64-69
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    • 2011
  • Since welding process for most pipelines with large diameter has been carried out by the manual process, automation of the welding process is necessary for the sake of consistent weld quality and improvement in productivity. Therefore the development of the optimized algorithm to decide the welding condition is an effective technique to prove the feasibility of interface standards and intelligent control technology to increase productivity and reduce the cost of system integration. In this study, the pipe welding experiment has been carried out using plused GMA welding process to select optimal welding condition. And necessary information in root-pass welding has been obtained by applying in the pipeline using the selected welding conditions through the welding experiment.

Method to Overcome Gap Variation by Control of Arc Force in Root Pass Welding for Back Bead by GMAW (GMAW 루트패스 이면비드 용접에서 아크력제어에 의한 갭변동 극복 방법)

  • Son, Chang-Hee;Cho, Sang-Myung
    • Journal of Welding and Joining
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    • v.29 no.6
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    • pp.77-81
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    • 2011
  • In most industry, manual GTAW welding is preferred for formation of stable back bead in root weld of butt joint. However, manual GTAW welding has low productivity as compared with GMAW, also it has unstable bead quality which depend on skilled workers. So it is necessary to develop process of root pass welding by using automation GMAW that have stable back bead formation and high productivity. In this paper, the design of U-groove with 3mm root face was applied to extend the tolerance of misalignment in condition of standard root gap 1.5mm. Consequently, for the formation of stable back bead in root pass of butt welding, in case of the narrow root gap(0.5mm) the large arc force was applied by increasing the current and voltage. In case of the large root gap(2.5mm), the small arc force was applied by decreasing the current and voltage. Considering the various root gap, the required deposited metal was controlled by welding speed only.

Friction welding of multi-shape ABS based components with Nano Zno and Nano Sio2 as welding reinforcement

  • Afzali, Mohammad;Rostamiyan, Yasser
    • Coupled systems mechanics
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    • v.11 no.3
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    • pp.267-284
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    • 2022
  • Due to the high usage of ABS in industries, such as aerospace, auto, recreational devices, boat, submarines, etc., the purpose of this project was to find a way to weld this material, which gives advantages, such as affordable, high speed, and good connection quality. In this experimental project, the friction welding method was applied with parameters such as numerical control (NC) machine with two different speeds and three cross-sections, including a flat surface, cone, and step. After the end of the welding process, samples were then applied for both tensile and bending tests of materials, and the results showed that, with increasing the machining velocity Considering of samples, the friction of the surface increased and then caused to increase in the surface temperature. Considering mentioned contents, the melting temperature of composite materials increased. This can give a chance to have a better combination of Nanomaterial to base melted materials. Thus, the result showed that, with increasing the weight percentage (wt %) of Nanomaterials contents, and machining velocity, the mechanical behavior of welded area for all three types of samples were just increased. This enhancement is due to the better melting process on the welded area of different Nano contents; also, the results showed that the shape of the welding area could play a significant role, and by changing the shape, the results also changed drastically.A better shape for the welding process was dedicated to the step surface.