• Journal of Welding and Joining
• /
• v.32 no.3
• /
• pp.1-10
• /
• 2014

The efficient application of any welding process depends on the understanding of associated process parameters influence on the weld quality. The weld quality includes the weld bead dimensions, temperature distribution, metallurgical phases and the mechanical properties. A detailed review on the experimental and numerical approaches to understand the parametric influence of a single wire submerged arc welding (SAW) and multi-wire SAW processes on the final weld quality is reported in two parts. The first part deals with the experimental approaches which explain the parametric influence on the weld bead dimensions, metallurgical phases and the mechanical properties of the SAW weldment. Furthermore, the studies related to statistical modeling of the present welding process are also discussed. The second part deals with the numerical approaches which focus on the conduction based, and heat transfer and fluid flow analysis based studies in the present welding process. The present paper is the first part.

• 제어로봇시스템학회:학술대회논문집
• /
• 1987.10b
• /
• pp.329-334
• /
• 1987

The purpose of this study is to monitor and control the back bead width in arc welding with consumable electrode for reduction of the occurrence of weld defect. The temperature of a point on the weldment surface is selected, as a monitoring parameter, and measured by an optical infra-red sensor. The correlation between the back bead width and the surface temperature is experimentally obtained for various thicknesses of the weldment. The welding travel speed and the surface temperature are taken, respectively, as an input and an output of the welding process under the stable condition of arc. A PI control scheme to maintain the surface temperature at the desired level is proposed by the experimental study.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.6 no.3
• /
• pp.26-35
• /
• 1997

In this study, the drawing characteristics of circular drawbead are examined with the plane strain elastic-plastic FE Method. Both the clamping load and the drawing load investigated by varying the process variables such as drawbead radius, closing depth and friction condition. The effective strain induced by the draw bead is also investigated. In order to verify the results, the computed results are compared with the existing experimental results. It has been found that both the clamping load and drawing loads are related with the geometry of the bead rather than the lubrication conditions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.11a
• /
• pp.151-152
• /
• 2005

Both $Al_2O_3$ and AlN nanopowders with diameters from ${\mu}m$ to mm were bead-milled and surface-modified by stabilizing agent. The size of bead-milled nanoparticles compared with the primary powder was effectively decreased and was dependent on milling time and bead size. The results of dispersion stability analysis indicated that chemical bonding between nanoparticles and surfactant is more effective than chemical adsorption to prepare the stable transformer oils containing nanoparticles. In this study, the thermal conductivity of the transformer oils containing nanoparticles was measured by transient hot-wire and laser flash methods.

• Proceedings of the KAIS Fall Conference
• /
• 2008.11a
• /
• pp.354-357
• /
• 2008

본 연구는 광전자촉매 시스템(PECS) 적용을 위하여 광촉매 금속판과 코팅비드를 제조하여 특성을 고찰하였다. 광촉매 물질의 회수가 용이하고, 실용화하기 위하여 티타늄 금속판을 $400^{\circ}C$에서 $700^{\circ}C$까지 $50^{\circ}C$에서 $100^{\circ}C$간격으로 토치를 사용하여 산화처리 하였으며, 비드의 경우 alumina, glass, silica gel beads에 TTIP([Ti$(OC_3H_7)_4$], Aldrich)을 전구체로 사용하여, 유동층 화학기상증착공정(Fluidized Bed Chemical Vapor Deposition, FB-CVD)으로 박막코팅을 하였다. 광촉매 금속판의 경우 산화처리 후 외관상태와 성분분석 시 최적조건은 $400^{\circ}C{\sim}500^{\circ}C$ 60분간 토치로 산화하였을 때였으며, 광촉매 코팅비드의 경우 silica gel beads가 본연의 다공구조를 나타내며 박막코팅이 되어, 상대적으로 alumina, glass beads에 비해 반응표면적이 크게 나타났다.

• Proceedings of the KWS Conference
• /
• 2003.05a
• /
• pp.155-158
• /
• 2003

Orbital GTA welding is used in the pressure pipe line of auto-mobile, LNG and plant piping. To weld the pipe line safely, to some extent, the back bead must be formed in the root pass. In the plate welding the back bead can be observed, but in the pipe welding, the back bead can not be observed directly. In the welding around circumference, the parameters such as gravity, surface tension and arc force are different at each position. And then D/B for welding condition at each position are required. We also studied about the setting of the optimum orbital welding condition by controlling heat input.

• Journal of Life Science
• /
• v.9 no.1
• /
• pp.45-49
• /
• 1999

Seaweed alginate was acetylated by activated carbon immobilized Pseudomonas syringae in a fluidized bed, up-flow reactor. The acetylation degree of seaweed alginate was about 30%. Calcium-acetylated seaweed alginate gel bead was made and compared to calcium-seaweed alginate gel bead by the scanning electron microscopy (SEM). Structural difference of two gel beads may results from increased viscosity and decreased affinity of acetylated seaweed alginate for calcium ion. On the basis of interior and exterior structure of calcium-acetylated seaweed alginate gels and property of acetylated seaweed alginate, it seems that acetylated seaweed alginate is used for the supporter for electrophoresis and packing materials for liquid chromatography and gel filtration.

• Journal of Welding and Joining
• /
• v.17 no.6
• /
• pp.46-52
• /
• 1999

The auxiliary gas-shielded MAG (AMAG) process, which was devised to provide an argon-rich shielding environment using small amount of argon gas, was investigated experimentally to figure out its effects on metal transfer and weld quality. Proper conditions for the AMAG process including the argon gas ratio, position and direction of the auxiliary nozzle were determined experimentally. Performance of the AMAG process was compared with that of the double gas-shielded MAG(DMAG) and MAG processes by monitoring the bead profile, current and voltage waveforms. The AMAG process was found to provide better bead profile, more stable arc and wider operating range of spray transfer mode compared with the DMAG process. In general, performance of the AMAG process using the argon ratio of 30% was comparable to that of the MAG process using 80% argon and 20% CO₂ gas.

• Transactions of Materials Processing
• /
• v.12 no.4
• /
• pp.320-327
• /
• 2003

This paper is concerned with forming analysis of Front Side Members and effects of the forming analysis on crash analysis of an auto-body. For efficient forming analysis, equivalent draw-bead restraining forces are calculated with ABAQUS/Standard and then used as the boundary condition in forming simulation. In order to demonstrate the validity of the forming analysis, the thickness variation in the numerical simulation result is compared quantitatively with the one in the real product. Forming histories obtained kom the forming analysis are utilized as the initial condition of the crash analysis for accurate assessment of the crashworthiness. Crashworthiness such as the load-carrying capacity, crash mode and the energy absorption is evaluated and investigated for the identification of forming effects.

• Journal of Welding and Joining
• /
• v.18 no.6
• /
• pp.55-61
• /
• 2000

Dynamic monitoring of weld pool formation and seam deviations using infrared vision is described in this paper. Isothermal contours representing heat dissipation characteristics during the process of arc welding were analysed and processed using imaging techniques. Maximum bead width and penetration were recorded and the geometric position in relation to the welding seam was measured at each sampling point. Deviations from the desired bead geometry and welding path were sensed and their thermographic representations were digitised and welding path were sensed and their thermographic representations were digitised and subsequently identified. Evidence suggested that infrared thermography can be utilized to compensate for inaccuracies encountered in real-time during robotic arc welding.