• Proceedings of the KWS Conference
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• 1991.11a
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• pp.35-37
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• 1991

• Proceedings of the KWS Conference
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• 1997.10a
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• pp.163-168
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• 1997

• Journal of Welding and Joining
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• v.21 no.6
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• pp.16-19
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• 2003

• Journal of Welding and Joining
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• v.18 no.6
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• pp.11-17
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• 2000

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.2
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• pp.186-192
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• 2002

The fatigue crack propagation characteristics were investigated on dissimilar friction weld of two kind of heat-resisting steels (STR3 and STR35) commonly used in valve materials for vehicles. A small circular artificial defect was machined to induce fatigue crack at bonded line, heat affected zone and base metal of the weld on the surface of the specimens. From the results of the experiment, the fatigue limits of the materials STR3 and STR35 were obtained to be 429.0MPa and 409.4MPa respectably. The STR35 base metal and 1.0mm HAZ specimens showed 190% and 82% higher fatigue life than STR3 base metal. And the fatigue life of 1.0mm HAZ specimen was shown 99% on STR3 and 29% on STR35 higher than that of their base metal. But the fatigue life of weld interface specimen was shown 18% on STR3 and 72% on STR35 lower than that of their base metal because of the weld interface separation.

• Journal of Welding and Joining
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• v.33 no.2
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• pp.56-61
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• 2015

IRW(Inverter Resistance Welding) process and DSW(Delta-spot welding) process for dissimilar materials of DP590 and Al5052 were performed to evaluate the welding quality and mechanical properties. IRW experiment was carried out with changing the welding current. The other welding parameters such as pressure force, weld time, squeezing time and holding time were fixed. On the anther hand, DSW experiment was performed using the process tape at welding current of 11.5kA. The other conditions were same as IRW conditions. The various testes such as shear tensile strength, nugget diameters, EDS, SEM and cross-sectional observation for weld zone was performed. As a result, IMC(Inter Metallic Compound) thickness at 11.5kA was thinner than those of 9.5kA and 10.5kA conditions. In addition, thined IMC layer was observed when high electric current apply to the materials(DP590 and Al5052) in a short time throught dissimilar resistance spot welding controling welding conditions. The relationship between the thickeness of IMC and current intensity was after discussed.

• Journal of the Korean Society of Safety
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• v.7 no.1
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• pp.65-72
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• 1992

Objective of this research is to evaluate fracture behaviors of fresh-butt welded metal by the acoustic emission technique. The specimens used are medium carbon steel(SM45C), mild steel (SS41) and stainless steel(SUS304), which have different weldability. The similar welding and dissimilar welding processes are considered, in the former SM45C, SS41 and SUS304 are used, in the later the following metals are used SM45C and SS41, SM45C and SUS304 and SS41 and SUS304. The characteristics of fracture in weld metal are eshmated by the tension test with nominal speciemns, the fracture toughness test with compact tension specimens and fractography analysis. The results of tension test show for base metals and similar welding materials that the yield strength and ultimate strength of similar welding materials are increased, the elongation of those are decreased. The weldability of SUS304 is better than that of SM45C and SS41 In similar welding materials. Mechanical properties of dissimilar welding mateiiths we lower than those of similar welding materials. In dissimilar welding materials, the weldability of SM45C and SUS304 is better than that of SM45C and SS41, and also weidability of SS41 and SUS304 is better than SS41 and SM45C. Comparing mechanical properties with AE counts, it is found that AE conuts appeared on a small before the limit load of elasticity(P$_{e}$), and apper greatly near yield strength region in tension test. These results could contribute to the safety analyses and the evaluation of strength for welding structure.e.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.12
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• pp.3028-3044
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• 1993

A metallic bond of great strength for the same or dissimilar metals can be produced by the explosive welding. The formation of a metallic jet at the interface between the two impacting plates has been simulated using the numerical hydrocode DYNA2D. The mechanism of explosive welding for the wave formation is also analyzed by the computer simulation technique. The microscopic with the experimentally observed behaviour of the explosive welding. The computer simulations of the explosive welding process have proven especially useful for analyzing the mechanism of metallic bones.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.4
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• pp.434-439
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• 2011

There are about 2.4million disabled in Korea, 2009. Also, Korean society entered into an aging society. Therefore disable and elderly are getting more involved in our society. This study proposes simple ramp design for wheel chair users and welding method and condition for manufacturing. In the middle of ramp, screw jack and motor are installed so that ramp can be moved left and right side. To make the ramp moves easily, ramp was fixed by installing LM guide on both sides. Ramp production for using Nd:YAG laser certain dissimilar welding in stainless steel sheet and cold reduced carbon steel. The output was fixed by 3kW, the speed was increased to 2~7m/min, Argon was used as shielding gas and the flow rate was changed to 10~30L/min. The proper welding condition is the output 3kW and welding speed 2~5m/min.

• Journal of Surface Science and Engineering
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• v.42 no.1
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• pp.34-40
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• 2009

In the study, it was carried out dissimilar metal welding on materials for Al ship. The electrochemical and mechanical characteristics evaluated for specimen welded by ROBOT. The hardness of welding zone is lower than those of heat affected zone and base metal. At the result of tensile test, the specimen welded with ER5183 welding material presented excellent property compared with ER5556. The polarization trend for the base metal and welding metal showed the effects of concentration polarization due to oxygen reduction and activation polarization due to hydrogen generation. At the Tafel experiments result, the corrosion density in welded with ER5183 welding material presented the lowest value.