• Journal of Ocean Engineering and Technology
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• v.24 no.2
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• pp.62-66
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• 2010

The goal of this work is to establish the reliability of FCA welded joints for high strength EH36-TMCP ultra thick plate. For this, heat conduction and thermo elasto-plastic analyses have been conducted on a multi-pass, X-groove, butt-joint model to clarify the thermal and mechanical behavior (residual stresses, magnitude of the stresses, and their production and distribution mechanisms) of the weld joint. In addition, the results of the welding residual stress obtained from thermo elasto-plastic analysis was verified and compared with results obtained by XRD analysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.5933-5938
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• 2014

In this study, the effect of varying the mixture gas during FCA welding was studied for an Atos 60 test piece. To examine the characteristics of welding, the weldability of the material was checked before welding and online monitoring was performed to examine the mechanical properties after welding. The mixture Ar 80% + $CO_2$ 20% at low speed gave very elegant beads with very little spatter. 100% $CO_2$ gave rise to high spatter generation. For Ar 80% + $CO_2$ 20%, the low current region due to the normal short circuits created spatter, which was more than double for 100% $CO_2$. This peak distribution occurred due to the instability of the arc. The tensile test result for Ar 80% + $CO_2$ 20%, Ar 90%+ $CO_2$ 10% and $CO_2$ 100% at 511MPa, 507MPa, and 469MPa showed that the yield strength was improved by 8.1 and 8.9% for 80%+ $CO_2$ 20% and Ar 90%+ $CO_2$ 10%, respectively, compared to 100% $CO_2$. The tensile test result at 622MPa, 609MPa, and 581MPa showed that the yield strength was improved by 7.0% for both the mixture gas compared to 100% $CO_2$.