• 제목/요약/키워드: Welding Length

검색결과 351건 처리시간 0.021초

용접부의 형상과 공정변화에 따른 소구경 분기배관의 피로강도 특성평가 (S-N Fatigue Strength of Small Diameter Branch Welded Pipe with Variation of Welding Shapes and Welding Procedures)

  • 백종현;김우식
    • Journal of Welding and Joining
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    • 제22권3호
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    • pp.50-55
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    • 2004
  • S-N fatigue tests were conducted to investigate the fatigue strength of small diameter socket and butt welded joints made of carbon steels. Experimental parameters were pipe diameter, throat depth, shape of socket welds and welding procedure. Filler metals used in SMAW and GTAW procedure were E9016-G with diameter of 4.0 m and ER70S-G with diameter of 2.4 m. API 5L Gr.B pipes were adopted as a small diameter branch pipes. All socket fittings were machined from ASTM A105 carbon steel. Tensile strength was not affected by the welding procedure. Fatigue strength in socket weld joints increased with increasing pipe diameter, area of weld metal and weld leg length of pipe side.

용접 각변형에 미치는 용접길이의 영향 (The Effects of Welding Length on the Angular Distortion)

  • 박정웅;강재완;정우현
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 2004년도 춘계 학술발표대회 개요집
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    • pp.232-233
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    • 2004
  • 강구조물 제작 시 용접프로세스에 의해 용접부 근방에 불균일한 온도분포가 발생하여 용접변형이 발생된다. 이러한 용접변형은 좌굴강도와 피로강도를 저하시킬 뿐 아니라 구조물의 크기와 형상을 변화시켜 이를 교정하거나 수정하기 위해 추가작업을 실시해야함으로 생산성을 저하시키는 주요한 요인이 되고 있다. (중략)

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디지털 화상처리를 이용한 차축 Casing Nut 용접부 치수 검사 프로그램 개발에 관한 연구 (A study on the development of dimension inspect Program for the vehicle axle casing nut welding part using digital image processing)

  • 김재열
    • 한국생산제조학회지
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    • 제9권5호
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    • pp.135-143
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    • 2000
  • The vision system is easy to use the exclusive use as a independent computer system but it is not much popularization by reason of expensive and difficult to adapt to the various fields, because it is easy to the existed computer system, the price is cheap and also it can use to the various measurement purpose which user wanted and programed. The measurement method of the vehicle axle casing nut welding part is that measure the value of the welding part to adapt the actual operation program from using the ratio between the actual length of the standard specimen and the length of image, to measure the ratio between the actual product and the camera image. A defect is found by the assembled visual inspection system. The inspection algorithm which estimates the quality of welded product is developed and also, the software program which processes the automatic test function of the inspection system. We make the foundation of the inspection automatic system and we will help to apply other welding machine.

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용접 후면 강제냉각조건이 용접각변형에 미치는 영향 (Effect of Forced Cooling condition along with Welding on Welding Angular Distortion)

  • 박정웅
    • 한국산학기술학회논문지
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    • 제14권4호
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    • pp.2021-2026
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    • 2013
  • 냉각법은 용접과 동시에 용접토치로 부터 일정한 거리 떨어져 있는 용접부를 냉각기체를 이용하여 냉각시켜 용접변형을 최소화시키는 기술이다. 냉각기체에 의해 용접부의 온도를 감소시키면 용접부에 발생하는 열응력이 감소되고 그 결과 소성변형이 최소화되어 최종적으로 용접좌굴과 각변형을 방지할 수 있는 기술이다. 이 방법은 용접부 표면을 냉각시키는 방법으로 용접부를 직접 냉각시킴으로서 현장 적용성 면에서 다른 용접변형 방지법 보다 효율적이다. 본 연구에서는 맞대기용접을 대상으로 용접 후면의 냉각조건(폭, 길이)을 변화시켜 열탄소성해석을 실시하여 해석적방법으로 용접 각변형에 미치는 영향을 검토하였다. 그 결과 용접토치와 냉각 선단과의 거리는 25mm, 냉각 길이는 80mm, 냉각 폭은 30mm의 경우가 각변형 저감에 제일 큰 효과가 있었다. 이때 냉각길이는 길면 길수록 각변형을 감소시킨다.

컨테이너선의 후 물재 용접부 취성 균열 전파에 대한 FCAW와 SAW의 비교 특성에 관한 연구 (Comparison of the Characteristics of FCAW and SAW for the Brittle Crack Propagation of Welded Parts of BCA Steel in Container Ships)

  • 최경신;이상훈;최정주
    • 한국기계가공학회지
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    • 제20권3호
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    • pp.24-32
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    • 2021
  • The size of container ships is increasing to increase the cargo loading capacity. However, container ships are limited in terms of the hull longitudinal strength. To overcome this limitation, brittle crack arrest steel can be used. This study was aimed at examining the influence of the heat input on the welding procedures of flux cored arc welding and submerged arc welding. In the experiment, the crack tip opening displacement test, which pertains to a parameter of fracture mechanics, was performed, and a 3-point bending tester was adopted. Based on the results, the crack measurement method was presented, and the stress expansion coefficient value for the pre-fatigue crack length was derived according to the heat input after the pre-cracking length was measured. It was noted that the heat input affected the crack tip opening displacement of brittle crack arrest steel.

GTA-GMA 하이브리드공정에 따른 자동차용 아연도금강판의 용접부 기공감소 (II) - 하이브리드공정 적용 결과 (Porosity Reduction during Gas Tungsten Arc-Gas Metal Arc Hybrid Welding of Zinc Coated Steel Sheets (II) - Hybrid Welding Results)

  • 안영남;김철희
    • Journal of Welding and Joining
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    • 제34권4호
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    • pp.48-54
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    • 2016
  • The use of Zn coated steel has increased in the automotive industry due to its excellent corrosion resistance. Conventionally the BIW(body-in-white) structure and the hang-on parts have been made of Zn coated steel and more recently Zn coated steel began to be applied in the chassis parts. During gas metal arc (GMA) welding of the chassis part, lap fillet joint used to be adopted but spatter generation and porosities are most important concerns. In the industrial applications, an intentional joint gap was made to avoid the weld defects but it is not easy to control the size of joint gap. In this research, gas tungsten arc (GTA) is combined with GMA welding where GTA precedes GMA. As pulsed arc was adopted as GMA, GTA was oscillated along the longitudinal direction by pulsing GMA, but the arc oscillation did not disturb the molten droplet transfer of GMA welding. By increasing the distance between GTA and GMA, the length of weld pool increased and porosity could be reduced. Moreover porosity in the welds was fully removed when the distance between two arcs was 15 mm.

자주포용 탄약 운반 궤도차량 도어힌지 용접부 구조강도 해석 (Structural Weld Strength Analysis on Door Hinge of Field Artillery Ammunition Support Vehicle)

  • 강현제;김병호;김병현;서재현
    • 한국기계가공학회지
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    • 제15권3호
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    • pp.58-65
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    • 2016
  • This study analyzed the structural weld strength for a door hinge for a field artillery ammunition support vehicle. In order to determine the optimal conditions, we measured the modal analysis and analyzed the leg length of a rear door hinge. From these methods, we acquired the vibration frequency of normal mode and the optimal welding leg length conditions. It was possible to obtain a structural stability for a rear door hinge of the field artillery ammunition support vehicle. In the future, this should be used as a reference source for the weld strength analysis of high vibration and high weight structures for another welding system design.

3차원 납 접합부 형상을 이용한 표면실장기술의 적정 납량 결정 (Determination of Adequate Solder Volume using 3D Solder Joint Configuration in SMT)

  • 최동필;김성관;유중돈
    • Journal of Welding and Joining
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    • 제14권2호
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    • pp.71-78
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    • 1996
  • In order to rpovide proper SMT design criteria in a systematic way, a mathematical formulation has been developed to predict the configuration of the solder fillet formed between the gullwing type lead and rectangular pad. Effects of SMT design parameters such as the solder volume and pad dimension on the solder profile are investigated using the FEM that calculates the 3D configuration by minimizing the energy due to surface tension and gravity in the equilibrium state. Design criteria of QFP and SOP are illustrated by plotting the acceptable range of the solder volume with respect to the length and width ratios of the pad and lead. The results show that the acceptable design range increases with increase in the pad length and width. The pad length has more significant effects on design criteria compared with the pad width, and Bond number can be utilized to predict the joint quality.

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Feasibility study on the wide and long 9%Ni steel plate for use in the LNG storage inner tank shell

  • Chung, Myungjin;Kim, Jongmin;Kim, Jin-Kook
    • Steel and Composite Structures
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    • 제32권5호
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    • pp.571-582
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    • 2019
  • This study aimed to assess the feasibility on the wide and long 9%Ni steel plate for use in the LNG storage inner tank shell. First, 5-m-wide and 15-m-long 9%Ni steel plates were test manufactured from a steel mill and specimens taken from the plates were tested for strength, toughness, and flatness to verify their performance based on international standards and design specifications. Second, plates with a thickness of 10 mm and 25 mm, a width of 4.8~5.0 m, and a length of 15 m were test fabricated by subjecting to pretreatment, beveling, and roll bending resulting in a final width of 4.5~4.8 m and a length of 14.8m with fabrication errors identical to conventional plates. Third, welded specimens obtained via shield metal arc welding used for vertical welding of inner tank shell and submerged arc welding used for horizontal welding were also tested for strength, toughness and ductility. Fourth, verification of shell plate material and fabrication was followed by test erection using two 25-mm-thick, 4.5-m-wide and 14.8-m-long 9%Ni steel plates. No undesirable welding failure or deformation was found. Finally, parametric design using wide and long 9%Ni steel plates was carried out, and a simplified design method to determine the plate thickness along the shell height was proposed. The cost analysis based on the parametric design resulted in about 2% increase of steel weight; however, the construction cost was reduced about 6% due to large reduction in welding work.