• Title, Summary, Keyword: FCAW

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A Study for the Weldability, Welding Position and Welded Joint Performance on the FCAW of HSA800 Steel (HSA800 강재의 FCAW 용접성, 용접자세 및 이음성능 연구)

  • Lee, Eun Taik;Kim, Jong Rak;Choi, Young Han;Kim, Sang Seup
    • Journal of Korean Society of Steel Construction
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    • v.28 no.4
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    • pp.281-292
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    • 2016
  • In this research, 10 specimens of FCAW welding with positions of 1G and 3G were tested to confirm the weldability, welding positions, and welded joint performance of 60mm HSA800 steel. The test results showed that FCAW 1G and 3G satisfied HSA800 steel's KS and the criteria for homogeneity of strength, indicating a good weld zones. However, according to the tensile test results of weld zone, 3G position FCAW welding requires improvement of welding techniques and methods.

Process Parameter Effect on Deformation of a V-groove Thin Plate for FCAW and EGW (V-groove 박판의 FCAW와 EGW 공정에 따른 변형에 미치는 공정인자 영향)

  • Han, Juho;Jeon, Jaeseung;Park, Chulsung;Oh, Chongin;Yun, Jinoh;Lee, Jeongsoo
    • Journal of Welding and Joining
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    • v.31 no.1
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    • pp.65-70
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    • 2013
  • Finite element analysis and welding experiments were performed to evaluate deformation aspect for Flux Cored Arc Welding(FCAW) and Electro Gas Welding(EGW). Numerical researches of FCAW and EGW were performed considering the difference of number of welding pass and welding direction to arc flow. To perform the numerical study of FCAW and EGW, number of welding pass and welding direction to arc flow were considered in the finite element model. FCAW process requires multi pass and its welding direction is vertical to welding torch. On the other hand, EGW process requires single pass and its welding direction is parallel to welding torch. The difference of welding direction and heat input was considered in the finite element analysis. In FCAW process, Goldak's double ellipsoidal heat input model was adopted. In the EGW process, Hemi-spherical power density distribution was adopted. In the results of experiment and finite element analysis, angular deformation of FCAW process is larger than that of EGW process.

Microstructure and CTOD (crack tip opening displacement) of Deposit Weld Metal in 30 mm Thick Plate

  • Lee Hae-Woo;Kim Hyok-Ju;Park Jeong-Ung;Kang Chang-Yong;Sung Jang-Hyun
    • Korean Journal of Materials Research
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    • v.14 no.9
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    • pp.642-648
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    • 2004
  • The microstructure and crack tip opening displacement (CTOD) of deposit weld metal were investigated for a 30 mm- thick plate welded with flux cored arc welding (FCAW) and submerged arc welding (SAW) processes. The CTOD test was carried out both as welded condition and as stress-relieved specimen by local compression. The crack growth rates in FCAW were faster than those in a SAW, and the acicular ferrite content by the SAW process was increased relatively more than that by the FCAW process. The fatigue crack growth rate in a welded specimen was faster than that in locally compressed specimen. The CTOD value of locally compressed specimens was lower than that of as welded specimen. Furthermore, the CTOD value tested with the SAW process was higher than that tested with the FCAW process.

A Study on the Effect of Welding Conditions on Fume Generation Rate in $CO_2$ Flux Cored Arc Welding ($CO_2$ FCAW에서 용접조건이 Fume발생량에 미치는 영향에 관한 연구)

  • 채현병;김정한;김희남
    • Journal of the Korean Society of Safety
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    • v.13 no.4
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    • pp.87-95
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    • 1998
  • The use of flux cored arc welding(FCAW) process has grown dramatically since it has been developed because of the remarkable operating characteristics and the resulting weld properties. The feature that distinguishes the FCAW process from other arc welding processes is the enclosure of fluxing ingredients within a continuously fed tubular electrode. The benefits of FCAW process are the increased productivity due to continuous wire feeding, the metallurgical effects derived from the reactions with flux, and the shapes of weld bead formed by slag. However, FCAW process causes the problem in working environment because it generates much more fume than other welding processes. Recently, the welding fume became a hot issue in the field after some welders were diagnosed as manganese toxcosis and siderosis. This study was started to investigate the characteristics of welding fume and utilize the results from the investigation to protect the welders from welding fume. As a first step, the effect of welding conditions on the fume generation rate(FGR) were investigated during FCAW process with $CO_2$ shielding. The considered welding conditions were welding current, arc voltage, travel speed, contact tube to work distance, and torch angle. The results showed that FGR was affected by all of these factors.

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Effects of Reduction Groove Angle on Strength Characteristics of FCAW Weldment (FCAW 용접부 개선각 축소에 따른 강도특성)

  • Lee, Sang-Chul;Jo, Sung Woo;Yang, Jong Soo;Choi, Kyu Won;Seo, Jung Kwan
    • Journal of the Society of Naval Architects of Korea
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    • v.53 no.6
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    • pp.473-481
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    • 2016
  • Thick plate is currently widely used in shipbuilding due to the increasing of size of ships. However, its use has increased welding groove angles and volume. The welder's technique must be good enough to improve productivity while preventing defects. Generally, the groove angle can be reduced to less than a flux-cored arc welding (FCAW) machine setting of $35{\pm}5^{\circ}$, requiring fewer welding passes while maintaining high productivity and reduced heat input. Therefore, welding technique can be prevented by improved mechanical properties and welding deformation. Welding defects such as lack of fusion (LF), lack of penetration (LP) and hot cracking should be considered when reducing the groove angle for related applications. In this study, a welding groove angle of $25{\pm}5^{\circ}$ is verified as suitable for FCAW design and fabrication. The experimental results confirm the effects on the strength characteristics of FCAW weldment when reducing groove angle to improve the productivity of shipbuilding industries.

A Study of Weldability and Welded Joint Performance on the Gas Shield Arc Welding (FCAW) of SM490TMC Steel Plate (120mm) (SM490TMC 극후판(120mm) 강재의 가스실드아크용접(FCAW)을 이용한 용접성 및 이음성능에 관한 연구)

  • Kim, Sung Bae;Hong, Hyung Ju;Choi, Young Han;Kim, Sang Seup
    • Journal of Korean Society of Steel Construction
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    • v.29 no.6
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    • pp.455-465
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    • 2017
  • To figure out the weldability and welded joint performance on the FCAW of SM490TMC 120mm, several specimens were manufactured and 10 kinds of experiments were implemented. The result of the weld zone chemical composition test, weld metal tensile test, weld zone tensile test, and weld zone impact test has satisfied the KS. Especially, the weld zone tensile test result shows the base metal fracture, which means the weld zone performs enough required performance. In addition, the results of the weld zone bending test, hardness test, macroscopic test, microscopic test, and the maximum hardness in HAZ were showing that the FCAW weld zone has fine quality.

Evaluation of Mechanical Test Characteristics according to Welding Position in FCAW Heterojunction (FCAW 이종접합에서 용접자세에 따른 기계적 시험 특성 평가)

  • Cho, Byung-Jun;Lee, Soung-Jun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.8
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    • pp.649-656
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    • 2019
  • Flux cored arc welding (FCAW), which is used widely in many fields, such as shipyards, bridge structures, construction machinery, and plant industry, is an alternative to shielded metal arc welding (SMAW). FCAW is used largely in the welding of carbon and alloy steel because it can be welded in all poses and obtain excellent quality in the field under a range of working conditions. In this study, the mechanical properties of welded parts were analyzed after different welding of SS400 and SM490A using FCAW. The following conclusions were drawn. The tensile test results satisfied the KS standard tensile strength in the range of 400~510 N/mm2 in all welding positions. The bending test confirmed that most of the specimens did not show surface breakage or other defects during bending and exhibited sufficient toughness, even after plastic deformation. The hardness test results were lower than the standard value of 350 Hv of KS B 0893. Similar to the hardness test, were greater than the KS reference value. The macro test revealed no internal flaws, non-metallic inclusions, bubbles or impurities on the entire cross section of the weld, and there were no concerns regarding lamination.

A Study on the Development of Arc Length Estimation Method in FCAW (FCAW에서의 아크 길이 추정 방법 개발에 관한 연구)

  • Bae, Kwang-Moo;Cho, Sang-Myung
    • Journal of Welding and Joining
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    • v.27 no.3
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    • pp.67-72
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    • 2009
  • The flux cored arc welding (FCAW) process is one of the most frequently employed and important welding process due to high productivity and excellent workability. The process is performed either as an automated process or as a semi-automatic process. In FCAW process, welding voltage has been considered as a qualitative indication of arc length. But it is necessary to let welding operators know, maintain and manage the arc length directly by estimating and displaying it. In this study, to develop arc length estimation technique, we measured a welding circuit resistance($R_sc$) and then we calculated welding circuit voltage drop($V_sc$). Also, we measured arc peak voltage($V_ap$). By subtracting $V_sc$ from $V_arc$, we can easily calculate net arc voltage drop($V_arc$). Consequently, we suggested arc length estimating equation and basic algorithm by regressive analyzing the relationship between net arc voltage drop($V_arc$) and real arc length(Larc) measured by high speed camera. Therefore, arc length can be predicted by just monitoring welding current and voltage.

A Study on Corrosive Characteristics of Inconel 625 for Petroleum Application by FCAW Process (석유시추용 인코넬 625강의 FCAW용접에 의한 부식성에 관한 연구)

  • PARK KEYUNG-DONG;AN DO-KEYUNG;AN JAE-PIL
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • pp.365-369
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    • 2004
  • Recently, Inconel 625 is used widely in offshore processing piping in order to extend the maintenance tenn and improve the quality of anti-corrosion. According to the resistance to attack in various corrosive media at temperatures from $200^{\circ}C$ to aver $1090^{\circ}C$, in combination with good low- and high-temperature mechanical strength. In general, High quality weldments for this material are readily produced by commonly used processes. in recent years, the flux cored arc welding(FCAW) process is becoming more popular due to higher deposition rate and a better weld quality as compared to the shielded metal arc welding (SMAW) process, at the same time, exhibiting equally good weld metal toughness similar to the SAW process. In this study, the weldability and weldment characteristics(mechanical properties and corrosive environment) of Inconel 625 are considered in FCAW weld associated with the several weld shielding gases($80\%Ar\;+\;20\%\;CO_2,\;50\%Ar\;+\;50\%\;CO_2,\;100\%\;CO_2$) in viewpoint of welding productivity.

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