• Title/Summary/Keyword: Butt joint welding

Search Result 179, Processing Time 0.02 seconds

Recent Application of Rail Joint Welding in Europe - Flash Butt Welding Gains Increasing Importance

  • Suk, H.G.;Killing, R.;Chung, W.H.;Park, J.U.
    • International Journal of Korean Welding Society
    • /
    • v.4 no.1
    • /
    • pp.1-9
    • /
    • 2004
  • Continuously welded tracks, first introduced on train lines, are being used increasingly in Europe. And the different arc welding methods are only used on minor lines, private tracks and in the manufacturing of switches and crossings. Mobile flash butt welding belongs the future in rail welding on side if new tracks have to be erected. The following contribution reviews the processes available, usual test methods for welded rail joints and various applications.

  • PDF

Mechanical Properties of the Flash Butt Welded Joint of 590MPa High Strength Steel (590MPa급 고강도강 플래시버트 용접이음부의 기계적특성)

  • Jeong, Bo-Young;Woo, In-Su;Kim, Jeong-Kil;Lee, Jong-Bong
    • Journal of Welding and Joining
    • /
    • v.25 no.2
    • /
    • pp.55-61
    • /
    • 2007
  • Flash butt weldability of 590MPa dual phase steel is carried out under micro metallographical examination and macro mechanical property tests. The objective of present study is to investigate the cause that brings on bond line fracture, and is to improve mechanical properties of the flash butt welded joint. The joint of flash butt welding has a superior tensile property, but has bad formability due to oxide formed at bond interface. The HAZ softening in the weld joint does not show. It was found that mechanical properties were increased with optimizing welding parameters and making application of oil dripping and post-weld heat treatment.

Friction Stir Welding Tool Geometries Affecting Tensile Strength of AA6063-T1 Aluminum Alloy Butt Joint

  • Kimapong, Kittipong;Kaewwichit, Jesada;Roybang, Waraporn;Poonnayom, Pramote;Chantasri, Sakchai
    • International journal of advanced smart convergence
    • /
    • v.4 no.1
    • /
    • pp.145-153
    • /
    • 2015
  • Friction Stir Welding (FSW) is a solid state welding that could successfully weld the difficult-to-weldmaterials such as an aluminum alloy. In this welding process, the stirrer of the welding tool is one of the important factors for producing the perfect sound joint that indicates the higher joint strength. So, this report aims to apply the friction stir welding using various stirrer geometries to weld the AA6063-T1 aluminum alloy butt joint, investigates the mechanical properties of the joint and then compares the mechanical properties with the microstructure of the joint. An experiment was started by applying the friction stir welding process to weld a 6.3 mm thickness of AA6063-T1 aluminum alloy butt joint. A study of the stirrer geometries effect such as a cylindrical geometry, a cone geometry, a left screw geometry and a right screw geometry at a rotational speed of 2000 rpm and a welding speed of 50-200 mm/min was performed. The mechanical properties such as a tensile strength and a hardness of the joint were also investigated and compared with the microstructure of the joint. The results are as follows. A variation of FSW Stirrer shape directly affected the quality AA6063-T1 aluminum alloy butt joint. A cylindrical stirrer shape and a cone stirrer shape produced the void defect at the bottom part of the weld metal and initiated the failure of the joint when the joint was subjected to the load during the tensile test. Left and right screw stirrer shapes gave the sound joint with no void defect in the weld metal and affected to increase the joint strength that was higher than that of the aluminum base metal.

A Study on a Dual Electromagnetic Sensor System for Weld Seam Tracking of I-Butt Joints

  • Kim, J.-W.;Shin, J.-H.
    • International Journal of Korean Welding Society
    • /
    • v.2 no.2
    • /
    • pp.51-56
    • /
    • 2002
  • The weld seam tracking system for arc welding process uses various kinds of sensors such as arc sensor, vision sensor, laser displacement sensor and so on. Among the variety of sensors available, electro-magnetic sensor is one of the most useful methods especially in sheet metal butt-joint arc welding, primarily because it is hardly affected by the intense arc light and fume generated during the welding process, and also by the surface condition of weldments. In this study, a dual-electromagnetic sensor, which utilizes the induced current variation in the sensing coil due to the eddy current variation of the metal near the sensor, was developed for arc welding of sheet metal I-butt joints. The dual-electromagnetic sensor thus detects the offset displacement of weld line from the center of sensor head even though there's no clearance in the joint. A set of design variables of the sensor was determined far the maximum sensing capability through the repeated experiments. Seam tracking is performed by correcting the position of sensor to the amount of offset displacement every sampling period. From the experimental results, the developed sensor showed the excellent capability of weld seam detection when the sensor to workpiece distance is near less than 5 ㎜, and it was revealed that the system has excellent seam tracking ability for the I-butt joint of sheet metal.

  • PDF

Effect of Process Variables on the Flash Butt Welding of High Strength Steel

  • Kim, Y.S.;Kang, M.J.
    • International Journal of Korean Welding Society
    • /
    • v.3 no.2
    • /
    • pp.24-28
    • /
    • 2003
  • This study was aimed to evaluate the quality of flash welded joints and optimize the welding process for flash butt welding of 780MPa grade high strength steel. And then the relationship between the welding process variables and the joint quality would be established. The effect of process variables between flashing and upsetting process was elucidated. Microstructure observation of the joint indicated that the decarburized band was mainly changed with upsetting process. Width of HAZ was also related to the upsetting conditions rather than the flashing conditions. Generally maximum hardness at HAZ was correlated with Ceq of steel and the empirical relationship was obtained to estimate the HAZ properties. Tensile elongation at the joint was usually decreased with increasing the initial clamping distance. Investigation of fracture surface after tensile and bending tests reveal that the origin of cracking at the joint was oxide inclusions composed of $SiO_2$, MnO, $Al_2O_3$, and/or FeO. The amount of inclusions was dependent on the composition ratio of Mn/Si in steel. If this ratio was above 4, the amount of inclusions was low and then the resistance to cracking at the joint was enough to maintain the joint performance. It was obtained that the flashing process influenced the conditions for the energy input to establish uniform or non­uniform molten layer, while the upsetting conditions influenced the joint strength. Heat input variable during flashing process was also discussed with the joint properties.

  • PDF

Fatigue Life Assessment of Steel Bridge Butt Joint Weld with Defects (강교량 맞대기용접 결함부의 피로수명 평가)

  • Baek, Yeong Nam;Jang, Yeong Gwon
    • Journal of Welding and Joining
    • /
    • v.18 no.2
    • /
    • pp.204-204
    • /
    • 2000
  • There are many weld defects such as surface crack, lack of fusion, and incomplete penetration(IP) in the butt joint weld of the existing steel bridges. The crack-like defects may significantly reduce the life of the structure. This paper presents the procedure and the results of the fatigue life assessment of the butt joints with weld defects in the existing steel girder bridge. The butt joint welds with incomplete penetration were instrumented with strain gages to determine the stress histogram under normal traffic. Based on the measured stress histogram the crack propagation analysis were performed for the fatigue life assessment. By using the suggested procedure and methodology, one can decide the time of periodic inspection and the necessity of repair of the butt joint welds with serious weld defects in the existing steel bridge. (Received October 1, 1999)

Fatigue Life Assessment of Steel Bridge Butt Joint Weld with Defects (강교량 맞대기용접 결함부의 피로수명 평가)

  • 백영남;장영권
    • Journal of Welding and Joining
    • /
    • v.18 no.2
    • /
    • pp.77-85
    • /
    • 2000
  • There are many weld defects such as surface crack, lack of fusion, and incomplete penetration (IP) in the butt joint weld of existing steel bridges. The crack-like defects may significantly reduce the fatigue life of the structure. This paper presents the procedure and the results of the fatigue life assessment of the butt joints with weld defects in the existing steel girder bridge. The butt joint welds with incomplete penetration were instrumented with strain gages to determine the stress histogram under normal traffic. Based on the measured stress histogram the crack propagation analysis were performed for the fatigue life assessment. By using the suggested procedure and methodology, one can decide the time of periodic inspection and the necessity of repair of the butt joint welds with serious weld defects in the existing steel bridge.

  • PDF

A study on weld distortion in butt and fillet welds of a steel plate by flux cored arc welding (플럭스코어드 용접으로 맞대기 및 필렛 용접된 판의 용접변형)

  • 안성철;유순영;조성택
    • Journal of Welding and Joining
    • /
    • v.7 no.4
    • /
    • pp.22-29
    • /
    • 1989
  • In this paper weld distortion both in butt and fillet welds by flux cored arc welding has been investigated by changing welding parameters such as heat input and plate thickness, and the weld distortion was expressed as a function of welding parameters adopting the inherent strain theory as proposed by Watanabe and Satoh in 1961. As results of the research it is proposed that transverse shrinkage in root pass butt welds in proportional to ln[(Q/t_-tan.theta.] where Q is heat input(cal/mm), t is plate thickness(mm), and 2.theta. is groove angle(degree), and angular distortion .phi.(radian) in one pass of fillet welds has the following relationship: .phi..var.(Q/ $t^{1.5}$)$^{3}$exp[-(Q/ $t^{1.5}$ )$^{2}$3/] These equations provide us with basic tools to predict the amount of weld distortion in welded structures.

  • PDF

Selection of Optimal Welding Condition in Root-pass Welding of V-groove Butt Joint (맞대기 V-그루브 이음 초층 용접에서 최적의 용접조건 선정)

  • Yun, Seok-Chul;Kim, Jae-Woong
    • Journal of Welding and Joining
    • /
    • v.27 no.1
    • /
    • pp.95-101
    • /
    • 2009
  • In case of manufacturing the high quality welds or pipeline, the full penetration weld has to be made along the weld joint. Thus the root pass welding is very important and has to be selected carefully. In this study, an experimental method for the selection of optimal welding condition was proposed in the root pass welding which was done along the V-grooved butt weld joint. This method uses the response surface analysis in which the width and height of back bead were chosen as the quality variables of the weld. The overall desirability function, which is the combined desirability function for the two quality variables, was used as the objective function for getting the optimal welding condition. In the experiments, the target values of the back bead width and the height are 6mm and zero respectively for the V-grooved butt weld joint of 8mm thickness mild steel. The optimal welding conditions could predict the back bead profile(bead width and height) as 6.003mm and -0.003mm. From a series of welding test, it was revealed that a uniform and full penetration weld bead can be obtained by adopting the optimal welding condition which was determined according to the method proposed.