• Title/Summary/Keyword: Electron Beam Welding(EBW)

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Effect of Welding Variables for EBW Process in AISI 4130 by Taguchi Method (다구찌 방법을 이용한 AISI 4130재료에서 EBW공정의 용접 변수 영향)

  • Kim, Won-Hoon
    • Journal of Welding and Joining
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    • v.15 no.6
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    • pp.66-77
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    • 1997
  • In the present work, Taguchi method for electron beam welding(EBW) process in AISI 4130 steel plate has been adopted for investigating the contribution of effect of welding variables. $A L_8(2^7)$ orthogonal array is adopted to obtain the effect of adjustment parameters. The adjustment parameters consist of accelerating voltage, beam current, travel speed and focus currrent. And the quality features selected for the EBW process are bead width of weldment, reinforcement, penetration depth, undercut and area of weld metal. Variance analysis is performed in order to check the effect of adjustment parameters on EBW. The mechanical properties of electron beam welded joints for each heat treatment conditions are investigated in comparison with those of base metal, especially from the view point of tensile and impact properties.

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The Comparison of Characteristic between Electron Beam Welding and Narrow-gap TIG welding with 316LN Stainless Steel (스테인레스강 316LN의 전자빔용접과 협개선TIG 용접특성 비교)

  • Jeong, In-Cheol;Kim, Yong-Jae;Lee, Gyeong-Un;Sim, Deok-Nam
    • Proceedings of the KWS Conference
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    • 2005.06a
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    • pp.82-84
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    • 2005
  • Among the advanced welding processes which are superior to conventional process, Electron beam welding and Narrow-gap TIG welding are most prospective in being applicable for the heavy industry field. With STS316LN, which is high strengthened austenitic stainless steel, the characteristic evaluation for these welding processes was carried out through the mechnical tests and property analyses. For the tensile strength EBW is better while in reverse for the yield strength. In Narrow-gap TIG the distribution of hardness values has some deviation according to the thickness direction while EBW has a tendency of a litter high hardness values in weld metal. After EB welding brings the reduction of nitrogen content, in TIG welding weld metal depends on the contents of welding material. Both processes have almost austenitic structure, but weld metal of EBW is also shown terrific structure

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The Characteristic Evaluation of Electron Beam Welding for Al 6061 alloy with thick-thickness plate (후판 Al 6061합금의 전자빔용접 특성 평가)

  • Jeong In-Cheol;Sim Deok-Nam;Kim Yong-Jae
    • Proceedings of the KWS Conference
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    • 2006.05a
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    • pp.68-70
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    • 2006
  • For the aluminum material of the thick-thickness more than 100mm Penetration depth Electron beam welding is effectively applicable with a characteristic of high energy intensity. But Al 6061 alloy has high crack sensitivity due to minor alloys, which are silicon, magnesium, copper etc. With a sample block of 135mm thickness EBW test was performed in vertical position. As tensile strength has $210{\sim}220N/mm^2$ with weld area broken. Bend test shows low ductility with fracture of partly specimens. Chemical contents of alloys show no difference between weld and base metal. Defect in middle weld area figures out typical hot crack due to low melting materials. Micro structure of weld area has some difference compare to HAZ and base metal. As a result of EBW test for Al 6061 alloy, it shows that weld defect could be occurred even though establishing of optimum weld parameter condition.

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Heat Source Modeling and Study on the Effect of Thickness on Residual Stress Distribution in Electron Beam Welding

  • Rajabi, Leila;Ghoreishi, Majid
    • Journal of Welding and Joining
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    • v.35 no.1
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    • pp.49-54
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    • 2017
  • In this study, the volumetric heat source in electron beam welding (EBW) is modeled through finite element method taking advantage of ABAQUS software package. Since this welding method is being applied in plates with different thicknesses and also considering that residual stresses reduce the strength of these weldments, the effect of thickness in the distribution and magnitude of residual stresses after welding is studied. Regarding the vast application of Inconel 706 super-alloy in aerospace industries, this material was selected in the current research. In order to validate the finite element model, the obtained results were compared to those of other researchers in this area, and good agreement was observed. The simulation results revealed that increase in the plate thickness leads to increase in the residual stresses. In addition heat treatment in the base metal (before welding) increases the residual stresses significantly.

A Study on electron beam veldability of 9%Ni steels (III) - Microstructures and mechanical properties of welded joints - (9%Ni 강의 전자빔 용접성에 관한 연구 (III) - 전자빔 용접부 기계적 특성과 조직 -)

  • 김숙환;강정윤
    • Journal of Welding and Joining
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    • v.15 no.4
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    • pp.116-125
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    • 1997
  • Electron beam weldability of 9%Ni steels has been investigated to apply EBW to the construction of LNG storage tank. While mechanical properties of welded joints were satisfied by ASTM specification, impact energy of weld metal was as low as 27 - 55J at $-196^{\circ}C$. As the result of Ni wires inserted at the joint to be welded, Ni content of weld metal was increased to about 10%, resulting on the improvement of impact toughness to 110 ~ 120J at $-196^{\circ}C$. This improvement of impact toughness in weld metal was due to the formation of tempered martensite and retained austenite. Above results indicate that, if Ni content of weld metal was increased about 10% by Ni wires addition, electron beam welded 9%Ni steels weld metal had sufficient impact energy necessary for a LNG storage tank.

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The Characteristics of EBW for strengthened austenitic stainless steel (강화 오스테나이트 스테인레스강의 전자빔 용접 특성)

  • 정원희;김용재;정인철
    • Proceedings of the KWS Conference
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    • 2003.05a
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    • pp.87-89
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    • 2003
  • The yield strengths of austenitic stainless steel have been approximately doubled by increasing the nitrogen content. But, the increasing the nitrogen cause of increase the pressure of metal vapor inside the keyhole in electron beam welding. During welding, eruptions of keyhole often occur that cause excessive spatter, concavity, and porocity in the weld zone. Additionally the fast evaporation of nitrogen content cause of decrease the strength of weld zone. Therefore in this paper, we investigated of the weldability of electron beam welding and the change of chemical content after welding for strengthened austenitic stainless steel, measured the deformation scale of both of electron beam and narrow gap TIG and the spike fluctuation in the root.

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A study on the Application Effect of Friction Stir Processing for Enhanced Pitting Corrosion Resistance of Stainless Steel Welds in Chloride Environment (염화물 환경에서 스테인리스강 용접부의 공식저항성 향상을 위한 마찰교반공정 적용효과에 관한 연구)

  • Jong Moon Ha;Deog Nam Shim;Seung Hyun Kim
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.19 no.2
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    • pp.84-92
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    • 2023
  • As temporary storage facilities for spent nuclear fuels in domestic nuclear power plants are expected to be saturated, external intermediate storage facilities would be required in the future. Spent nuclear fuels are stored in metal canisters and then placed in a dry environment within concrete or metal casing for operation. In the United States, the dry storage method for spent nuclear fuels has been operated for an extended period. Based on the corrosion experiences of dry storage canisters in chloride environments, numerous studies have been conducted to reduce corrosion in welds. With the construction of intermediate storage facilities in Korea for spent nuclear fuels expected near coastal areas adjacent to nuclear power plants, there is a need for research on the corrosion occurrence of welds and mitigation methods for canisters in chloride environments. In this paper, we measured and compared the residual stresses in the Heat-Affected Zones (HAZ) after electron beam welding (EBW) and gas tungsten arc welding (GTAW) processes for candidate materials such as 304L, 316L, and duplex stainless steel(DSS). We investigated the possibility of microstructure control through the application of surface modification processes using friction stir processing (FSP). Corrosion tests on each welded specimen revealed a higher corrosion rate in EBW welds compared to GTAW. Furthermore, it was confirmed that corrosion resistance improved due to phase refinement and redistribution of precipitates when FSP was applied.

A Study on Microstructures and Cryogenic Mechanical Properties of Electron Beam Welds between Cast and Forged Inconel 718 Superalloys for Liquid Rocket Combustion Head (액체로켓 연소기용 Inconel 718 주조 및 단조 합금의 전자빔 용접부 미세조직 및 극저온 특성)

  • Hong, Hyun-Uk;Bae, Sang-Hyun;Kwon, Soon-Il;Lee, Je-Hyun;Do, Jeong-Hyeon;Choi, Baig-Gyu;Kim, In-Soo;Jo, Chang-Yong
    • Journal of Welding and Joining
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    • v.31 no.6
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    • pp.50-57
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    • 2013
  • Characterization of microstructures and cryogenic mechanical properties of electro beam (EB) welds between cast and forged Inconel 718 superalloys has been investigated. Optimal EBW condition was found in the beam current range of 36~39 mA with the constant travel speed of 12 mm/s and arc voltage of 120 kV for 10 mm-thick specimens. Electron beam current lower than 25 mA caused to occur the liquation microfissuring in cast-side heat affected zone (HAZ) of EB welds. The HAZ liquation microfissure was found on the liquated grain boundaries with resolidified ${\gamma}/Laves$ and ${\gamma}/NbC$ eutectic constituents. EBW produced welds showing a fine dendritic structure with relatively discrete Laves phase due to fast cooling rate. After post weld aging treatment, blocky Laves phase and formation of ${\gamma}^{\prime}+{\gamma}^{{\prime}{\prime}}$ strengtheners were observed. Presence of primary strengthener and coarse Laves particles in PWHT weld may cause to reduce micro-plastic zone ahead of a crack, leading to a significant decrease in Charpy impact toughness at $-196^{\circ}C$. Fracture initiation and propagation induced by Charpy impact testing were discussed in terms of the dislocation structures ahead of crack arisen from the fractured Laves phase.

Evaluation of Structural Stability for a 75-tonf Class Thrust Chamber Mixing Head (75톤급 연소기 헤드부의 구조안정성 평가)

  • Ryu, Chul-Sung;Lee, Keum-Oh;Choi, Hwan-Seok
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.11a
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    • pp.515-519
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    • 2011
  • Structural tests for the mixing head of a 75tonf class thrust chamber were performed to verify structural stability. The mixing head of a thrust chamber is loaded by high pressure with regeneratively cooled fuel and cryogenic liquid oxygen(LOx) as well as it transfers thrust load generated by liquid rocket engine. Therefore structural stability of mixing head is a very important factor to work without any plastic deformation or structural failure. In this study, two mixing heads were manufactured using different welding methods, Tungsten Inert Gas(TIG) welding and Electron Beam Welding(EBW) and evaluated a structural stability. The results of structural tests showed that the mixing head assembled by EBW can withstand the applied design load without any structural failures and be structurally more stable than that of TIG welding.

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