• Title/Summary/Keyword: lap welding

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A Study on the Feasibility of Partial Penetration Laser Welding for the Lap Joint of 390MPa High Strength Steel Sheets (390MPa급 고장력강판의 경치기 레이저 용접에서 부분용입 용접의 적용 가능성에 대한 연구)

  • 이경돈;박기영;김주관
    • Journal of Welding and Joining
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    • v.20 no.2
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    • pp.95-101
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    • 2002
  • After high power lasers are avaliable in the commercial market, the number of applications of the laser welding has been increased in manufacturing industries. Although the tailored blank laser welding of butt jointed steel sheets is well known recently in the automotive industries, the lap joint laser welding is a new technology to the automotive manufacturing people as well as the design people. But the deep penetration laser welding seems to be preferred to the partial penetration welding for the lap joint welding in the automotive manufacturers because the partial penetration is a serious deflect for the butt joint. In this study, the feasibility of partial penetration welding fur the lap joint $CO_2$ laser welding was studied fur the 1mm thick 390MPa high strength steel sheets for automotive bodies. The process window of the lap joint partial penetration welding was obtained from experiments with the gap size and the welding speed as process parameters. The partial penetration welding was found excellent on the basis of the tensile shear strength and sectional geometry. The bead width, input energy Per volume, tensile-shear strength, deformation energy and the sectional geometries after tensile-shear tests of partial penetration welded specimens are compared with those of full penetration welded specimens with a series of gaps and welding speeds.

A Study on the Fatigue Strength and Allowable Stress of INVAR(Fe-36% Ni) Steel Lap Joint Applied to Cargo Containment of LNG Carrier (LNG선용 INVAR(Fe-36%Ni)강 Lap 이음부의 피로강도와 허용응력에 관한 연구)

  • 한명수;한종만;한용섭
    • Journal of Welding and Joining
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    • v.12 no.1
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    • pp.102-115
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    • 1994
  • This paper is to evaluate the fatigue strength of lap joints of materials applied to LNG carrier cargo containment of GAZ-TRANSPORT(GT) type, which was welded by manual and automatic TIG welding process. The thicknesses of lapped members were 1.5mm/1.5mm or 1.5mm/0.7mm in Invar to Invar joint, and 1.5mm/8.0mm in Invar to stainless steel joint, respectively. These lap joints were mainly applied to the membrance fabrication of GT-LNG carrier. Fatigue tests of Invar/Inar lap joints were conducted under the stress ratio R=0 at room temperature. The effect of mean stress and cumulative fatigue damage on the allowable stress of Invar lap joint was evaluated on the basis of test results. Fatigue test was also conducted on Inver/Stainless steel lap joints welded by automatic TIG process without filler metals. The fatigue test of the joint was carried out under the same conditions as those of Invar/invar lap joints. The fatigue strength of the joint welded without filler metal was comparable to those welded with filler metal quoted from reference. The fatigue strength of Invar/stainless steel lap joint was only dependent on the lap throat thickness, and not on the welding process. Based on test results, the applicability of TIG welding process without filler metal in Invar/stainless steel lap joint was reviewed by controlling welding variables to assure the valid throat thickness of lap joints.

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Weldability and Optimum Welding Conditions on the 4 Lap Spot Welded Joint of High Strength Steel Sheets in Automobile (고장력 강판 적용에 따른 자동차용 4겹 다층 점용접물의 용접성 및 적정 용접조건)

  • Kwon Il-Hyun;Kim Hoi-Hyun;Baek Seung-Se;Yang Seong-Mo;Yu Hyo-Sun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.30 no.5 s.248
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    • pp.481-487
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    • 2006
  • Spot-welding is a widely used manufacturing method for thin-sheet components, especially in mass-production industries such as the car industry. Automobiles are often constructed by multi-lap spot welding to secure the passenger from the accident, where optimisation of the welding conditions is a major economic consideration. This research is conducted to investigate weldability characteristics with various welding conditions on the 4-lap spot welded joint of structural steel sheets in automobile. The relationship between the tensile-shear strength and the indentation depth has been investigated to propose the optimum welding conditions. The welding current and the welding time have a greater effect on the welding characteristics than the electrode force. It was found that the electrode force has a relatively close relationship with the expulsion occurrence. The design curves for optimum welding are proposed for the 4-lap spot welded joint.

Evaluation of Welding Characteristics on 3-lap Spot Joint of Zinc Coned Seel Sheet md High Seength Steel Sheet (아연도금 강판과 고장력 강판 3겹 점용접물의 용접특성 평가)

  • Kwon Il-Hyun;Kim Hoi-Hyun;Baek Seung-Se;Yang Seong-Mo;Yu Hyo-Sun
    • Transactions of the Korean Society of Automotive Engineers
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    • v.13 no.5
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    • pp.42-49
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    • 2005
  • In general, multi-lap spot weld joints are frequently present in automobile. Most research, however, has been focused on the single-lap spot weld joints until now. In this paper, tensile-shear strength tests are performed to examine the weldability of 3-lap spot joint welded by using the high strength steel sheet and the zinc coated steel sheet. The indentation depth and nugget diameter are used to propose the optimum welding conditions. The weldability is affected by the welding current and welding time for 3-lap spot joint. Meanwhile the expulsions is round to decrease with the increase of electrode force. The optimum welding conditions are presented for 3-lap spot joints of high strength steel sheet and zinc coated steel sheet.

The Porosity Control Technology of Lap Joint Welding Using Continuous Wave Nd:YAG Laser of the Low Carbon Steel SS41 (저탄소강 SS41 연속파형 Nd:YAG 레이저 겹치기 용접의 기공제어 기술)

  • Lee, Ka Ram;Hwang, Chan Youn;Yang, Yun Seok;Park, Eun Kyeong;Yoo, Young Tae
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.22 no.4
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    • pp.665-672
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    • 2013
  • With the development of advanced processing technology, laser processing systems, which require high-quality precision processing, have attracted considerable attention. Although laser equipment is expensive, it enables quick processing and less deformation of materials. This technology is often applied to secondary batteries, which has thus farinvolved the use of argon tungsten inert gas (TIG) welding. However, the welding characteristics of argon TIG welding are not yet good, and a laser is used for welding to address this problem. In this study, lap-joint welding was conducted, and the desired welding characteristics were obtained when the laser power was 1800W and the laser beam travel speed was 1.8 m/min. Lap-joint welding was conducted on Ni-coated SS41. Two cases were compared. No pores were observed in the Ni-coated SS41 lap-joint welding part, and cracks appeared from the lap-joints. Moreover, the pole rod and tap were welded together in a T-joint form to improve the output of the secondary battery. T-joint laser welding showed better welding characteristics than TIG welding.

Effect of Resistance Spot Welding Parameters on AA1100 Aluminum Alloy and SGACD Zinc coated Lap Joint Properties

  • Chantasri, Sakchai;Poonnayom, Pramote;Kaewwichit, Jesada;Roybang, Waraporn;Kimapong, Kittipong
    • International Journal of Advanced Culture Technology
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    • v.3 no.1
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    • pp.153-160
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    • 2015
  • This article is aimed to study the effects of resistance spot welding (RSW) on the lap joint properties between AA1100 aluminum alloy and SGACD zinc coated steel and its properties. The summarized experimental results are as follows. The summarized experimental results are as follows. The optimum welding parameters that produced maximum tensile shear strength of 2200 N was a welding current of 95 kA, a holding time of 10 cycles, and a welding pressure of 0.10 MPa. Increasing of welding current, increased the tensile shear strength of the joint and also increased the amount of aluminum dispersion at the joint interface. The lap joint of steel over the aluminum (Type I) showed the higher joint tensile shear strength than a lap joint of aluminum over the steel (Type II). The indentation depth and the ratio of the indentation depth to the plate thickness decreased when the welding current was increased in the type I lap joint and also decreased when the welding current was decreased in the type II lap joint. The interface structure showed the formation of the brittle $FeAl_3$ intermetallic compound that deteriorated the joint strength.

Friction Stir Spot Welding of AA5052 Aluminum Alloy and C11000 Copper Lap Joint

  • Prasomthong, Suriya;Sangsiri, Pradit;Kimapong, Kittipong
    • International Journal of Advanced Culture Technology
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    • v.3 no.1
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    • pp.145-152
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    • 2015
  • The article aims to apply a friction stir spot welding for producing the lap joint between AA5052 aluminum alloy and C11000 copper alloy. The dimension of the materials was 100 mm in length, 30 mm in width and 1.0 mm in thickness. The copper plate was set overlap the aluminum plate by 30 mm. The welding parameter was the rotating speed of 2500-4000 rpm, the pin inserting rate of 2-8 mm/min and the holding time of 6 sec. The mechanical properties test and the microstructure investigation were performed to evaluate the lap joint quality. The summarized results are as follows. The friction stir spot welding could produce effectively the lap joint between AA5052 and C11000 copper. Increase of the rotating speed and holding time directly affected to decrease the tensile shear strength of the lap joint. The optimized welding parameters in this study that indicated the tensile shear strength of 864 N was the rotating speed of 3500 rpm, the pin inserting rate of 6 mm/min and the holding time of 4sec. The experimental results also showed that the hardness of the weld metal was lower than that of the base materials.

Development of Laser Vision Sensor with Multi-line for High Speed Lap Joint Welding

  • Sung, K.;Rhee, S.
    • International Journal of Korean Welding Society
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    • v.2 no.2
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    • pp.57-60
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    • 2002
  • Generally, the laser vision sensor makes it possible design a highly reliable and precise range sensor at a low cost. When the laser vision sensor is applied to lap joint welding, however. there are many limitations. Therefore, a specially-designed hardware system has to be used. However, if the multi-lines are used instead of a single line, multi-range data .:an be generated from one image. Even under a set condition of 30fps, the generated 2D range data increases depending on the number of lines used. In this study, a laser vision sensor with a multi-line pattern is developed with conventional CCD camera to carry out high speed seam tracking in lap joint welding.

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A Study on Welding Distortion of GTA Circular Type Lap Joint in STS304L Thin Plate (STS304L 박판 원형 겹치기 GTA 용접부의 용접 변형 예측에 관한 연구)

  • Kim, Il-Ho;Kim, Ha-Geun;Shin, Sang-Beom;Park, Dong-Hwan
    • Journal of Welding and Joining
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    • v.30 no.5
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    • pp.57-63
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    • 2012
  • The purpose of this study is to evaluate the welding distortion of the circular type lap joint in STS304L of 0.7mm thickness by using FEA. In order to do it, a heat input model for GTA welding process with non-consumable electrode was established through comparing the molten pool shapes and temperature distributions obtained by both FEA and experiment. With the heat input model, the welding distortion of the circular type lap joint was evaluated by 3-D FEA. From FEA results, it was found that 3-D FEA with proper heat input model can be used for the evaluation of the excessive distortion of the circular type lap joint of STS304L thin plate. In addition, the root cause of the excessive distortion in the weld was also identified as the excessive compressive residual stress in the tangential direction of the weld.

Development of Microstructure and Mechanical Properties of Friction Stir Lap Jointed Invar 42/SS 400 (겹치기 마찰교반접합된 Invar 42/SS 400 합금의 미세조직과 기계적 특성 발달)

  • Song, K.H.;Nakata, Kazuhiro
    • Journal of Welding and Joining
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    • v.30 no.5
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    • pp.34-39
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    • 2012
  • This study was conducted to investigate the microstructure and mechanical properties of friction stir lap joints. Invar 42 and SS 400 were selected as the experimental materials, and friction stir welding was carried out at a tool rotation speed of 200 rpm and welding speed of 100 mm/min. The application of friction stir welding to Invar 42 effectively reduced the grain size in the stir zone; the average grain size of Invar 42 was reduced from $11.5{\mu}m$ in the base material to $6.4{\mu}m$ in the stir zone, which resulted in an improvement in the mechanical properties of the stir zone. The joint interface between Invar 42 and SS 400 showed a relatively sound weld without voids and cracks, and the intermetallic compounds with $L1_2$ type in lap jointed interface were partially formed with size of 100 nm. Moreover, the hook in the advancing side of Invar 42 was formed from SS 400, which contributed to maintenance of the tensile strength. The evolution of microstructures and mechanical properties of friction stir lap jointed Invar 42 and SS 400 are also discussed herein.