• Proceedings of the KWS Conference
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• 2005.06a
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• pp.217-219
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• 2005

In the conventional GMAW of 9% Ni steel, Inconel wire has been employed. The major problem of the Inconel GMAW is that arc stability and fluidity of weld pool is poor. Lack of fusion and convex weld bead is liable to occur in case of 9% Ni steel because of low melting point of Inconel wire. In this study the effect of shielding gases on the Inconel 625 GMA weldability was investigated.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.1
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• pp.89-94
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• 2015

This study was conducted to compare the laser weldability of boron steel and hot-stamped steel. In general, boron steel is used in the hot-stamping process. Hot-stamping is a method for simultaneously forming and cooling boron steel in a press die after heating it to the austenitizing temperature. Hot-stamped steel has a strength of 1500 MPa or more. Thus, in this study, the laser weldability of boron steel and thet of hot-stamped steel were investigated and compared. A continuous wave disk laser was used to produce butt and lap joints. In the butt welding, the critical cooling speed at which full penetration was obtained in the hot-stamped steel was lower than that of boron steel. In the lap welding, the joint widths were similar regardless of the welding speed when full penetration was obtained.

• Journal of Welding and Joining
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• v.26 no.5
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• pp.79-89
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• 2008

With the increased use of surface textured steel sheet in body-in-white assembly, resistance spot weldability of these steels is considered to be an important subject. This study evaluated nugget formation and weldability by measuring dynamic resistance with various weld pressure, current, and weld time for steel sheet with two different surface roughnesses. The surface roughness for T-H steel ($R_{a}=1.70\;{\mu}m$) was higher than that for T-L steel ($R_{a}=1.33\;{\mu}m$), and resulted in increased contact resistance and heating for T-H steel spot welding. Therefore, at low weld current and weld cycle ranges, the T-H steel showed better weldability over the T-L steel. The evaluations of weld interface showed that the fusion zone in the T-H steel sheet was continuous in contrast to discontinuous fusion zone for T-L steel sheet at the same welding conditions. A comparison of dynamic resistance and tensile-shear strength (TSS) between T-H and T-L steel sheet suggested that high surface roughness provided larger heating at early cycle of welding and larger TSS.

• The Journal of the Convergence on Culture Technology
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• v.9 no.1
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• pp.605-611
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• 2023

In this study, in order to reduce energy that affects the natural environment, a moving iron core type welding machine and a digital welding machine (inverter type) with low power consumption are compared in shielded arc welding, and the parts that use less power and have the same weldability conditions are identified. want to check. The movable iron core welder uses alternating current that outputs a sine wave, and the digital welder also generates a sine wave alternating current, so it must have the same conditions, low power consumption, and the same weldability. However, weldability can be verified in various ways, but the analysis is limited to the qualification test in the field of national technical qualification welding.

• Journal of Korean Society of Steel Construction
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• v.15 no.2
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• pp.147-157
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• 2003

The application in steel structures is increasing the mill sheet for the weathering steels by minimum maintenance cost in a life cycle cost. These have been collected and statistically analyzed to investigate chemical compositions, mechanical properties, weldability indices, weathering index and impact absorbed energy. From this study, although the band of dispersion in chernical compositions, mechanical properties and impact absorbed energy of the weathering steels appeared a little larger, the results revealed that these values have adequately satisfied the standard values of the Korean Standard. Furthermore, it was found that the weldability indices and the weathering index for the weathering steels have respectively satisfied the value prescribed by the Japanese Highway Specification and ASTM.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.4
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• pp.613-618
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• 2012

The Ultrasonic metal welding is used in the solid-phase welding method at room temperature or low temperature state. In welding process, the high frequency vibration energy is delivered to the welding part under the constant pressure for welding. In this study, we aimed to design and manufacture a 40,000 Hz band horn through finite element analysis. By performing modal analysis and harmonic response analysis, the modal analysis result is that the horn frequency was 39,599Hz and the harmonic response result that the horn frequency was 39,533Hz. These results were similar. In order to observe the designed horn's performance, about 4,000 voltage data was obtained from a light sensor and was analyzed by FFT analysis using Origin Tool. The result RMS amplitude was approximately $8.5{\mu}m$ at 40,000Hz, and maximum amplitude was $12.3{\mu}m$. Using this manufactured horn along with an ultrasonic metal welder and tension tester, the weldability of Cu sheets was evaluated. The maximum tensile force was 66.53 N in the welding condition of 2.0 bar pressure, 60% amplitude, and 0.32 s welding time. In excessive welding conditions, it was revealed that weldability is influenced negatively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.3
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• pp.1070-1077
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• 2011

This paper is studied on the influence of machining conditions on weldability obtained by ultrasonic machining. The weldability estimation of dissimilar Ni-Cu sheets with the optimization of one-wavelength horn is confirmed by the use of ultrasonic machining. The optimal welding condition with tensile test by setting the ultrasonic machining parameters is suggested and the weldability is estimated by SEM observation and EDX-ray analysis. Experimental studies are worked with the measure of tensile strength and the analysis of SEM photograph after the ultrasonic machining of workpiece. Machining parameters of machining time, pressure, and amplitude are also applied to this paper.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.1
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• pp.68-74
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• 2011

This papers investigated the mechanical characteristics and the weldability of identical as well as dissimilar welding by GTAW for STS 304 and STS 316L. It is applied to double wall gas pipe of duel fuel engine for LNG carrier. Consequently, the weldability of dissimilar and identical welded zone of STS 304 decreased compared to base metal significantly. The result of microstructure observation for welded zone, a degree of acicular ferrite in welding zone for STS 304 presented more than STS 316L. The hardness of welding zone for STS 304 presented higher value than that for STS 316L by this effect.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.2
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• pp.173-178
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• 2007

Improvement of welding property of seat fiame is necessary for safety because seat frame is a unique connecting structural part between the rider and vehicle. Generally the robot and jig system for own use is used for welding of seat frame and unwelded zone can be inspected because of the geometrical interference between robot and jig system. In this study the unwelded zone of the conventional welding jig system is analysed and the 3D modeling and design change to solve the problem is discussed. As a result the weldability of system is improved and the manual welding jig is unnecessary because of the optimal jig system.

• Journal of Korean Society of Steel Construction
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• v.29 no.1
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• pp.37-48
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• 2017

In this research, 9 SAW welding specimens with 1 hour post-heat treatment (PH1) and 2 hours (PH2) were experimented to confirm the weldability and the joint performance of 60mm thickness HSA800 steel. SAW tests with PH1 & PH2, including weld impact test, bend test, hardness test, macroscopic test, and microscopic test, had a good test results. However, from the chemical composition test results, P composition was not satisfied with Korean Industrial Standards(KS). According to the weld-zone tensile tests, 2 hours post-heat SAW is recommended because the mechanical characteristics of SAW PH2 were better than those of SAW PH1.