The Experts below are selected from a list of 249 Experts worldwide ranked by ideXlab platform
M N James - One of the best experts on this subject based on the ideXlab platform.
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process parameter influence on performance of friction taper Stud welds in aisi 4140 steel
Materials & Design, 2011Co-Authors: D G Hattingh, D L H Bulbring, A Elsbotes, M N JamesAbstract:Abstract Friction taper Stud Welding is a new variant of friction Welding which has been developed from the principles of friction hydro-pillar processing. This paper considers the effect of weld process parameters on weld defects, macrostructure and mechanical properties in AISI 4140 steel. It also presents 3D residual stress data for a typical friction taper Stud weld. Applied downwards force, rotational speed and plunge depth (equivalent to consumable length) of the Stud tool were systematically varied whilst measuring tool torque and temperature at several locations during Welding. A simple Taguchi analysis was then used to relate process parameters and weld tensile strength. The combinations of parameters leading to high tensile strength are identified and linked to the occurrence of specific weld defects.
Shinji Kumai - One of the best experts on this subject based on the ideXlab platform.
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Effect of Coating Layer on Advanced Stud Welding of 2024 Aluminum Alloy to Galvanized and Galvannealed Steel Sheet
2016Co-Authors: Yohei Harada, Kozo Ishizuka, Shinji KumaiAbstract:Abstract. High strength 2024 aluminum alloy Studs were joined to galvanized, galvannealed and non-coated steel sheets by using an advanced Stud Welding method. Effect of the coating layer on the interfacial microstructure and the tensile fracture load of the joints were evaluated. A specially-designed Stud having a circular projection at its bottom was pressed against a sheet surface. A discharge current was introduced from the upper part of the Stud. Local heating could be achieved by a high current density at a contact point between the projection and sheet. The observation of joint area revealed the projection was severely deformed and spread along the sheet surface. The coating layer of the galvanized steel sheet was removed at the joint interface under the charging voltage of 200 V, while that of the galvannealed one locally remained on the steel surface even at 400 V. This would be strongly related to the melting or liquidus and solidus temperatures of each coating layer. Joining was not achieved at a low charging voltage in the non-coated and galvannealed steel sheets, while high tensile fracture load was obtained even at 200 V in the galvanized ones
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Dissimilar-metal joining using several types of high-speed solid-state Welding methods
2016Co-Authors: Shinji KumaiAbstract:numerical analysis Abstract. Solid-state Welding is useful to join dissimilar metal couples, in particular, with a large difference in physical and mechanical properties. However, conventional solid-state Welding methods such as diffusion Welding and roll bonding are not necessarily applicable to all metal combinations. In addition, they are time-consuming. In the present Study, various dissimilar metal joints (e.g. Al/Fe, Al/Cu, Al/Ni, A2024/A5052, A6022/steel, A6022/Plated steel, A2024/AZ80) were fabricated by using several types of high-speed solid-state Welding methods; friction stir spot Welding, advanced Stud Welding and impact Welding. The strength and characteristic interfacial morphology of the joints were investigated, and each joining mechanism is discussed. In particular, for the impact Welding, both experimental and numerical analyses were performed. Two metal sheets were obliquely collided at a very high speed and joined by magnetic pressure or explosive force. Smoothed Particle Hydrodynamics (SPH) method was used to simulate the impact Welding process. The emission of metal jet and the evolution of characteristic wavy interface at the joint interface could be clearly visualized. The effects of collision angle, collision velocity and difference in density of the metals on the wave morphology were revealed
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Joining steel Studs and steel plates by solid-state Stud Welding and estimation of temperature near the joint interface
Journal of Manufacturing Processes, 2016Co-Authors: Yohei Harada, Yutaro Sada, Shinji KumaiAbstract:Abstract In solid-state Stud Welding, joining is completed within a few milliseconds by using a large discharge current and pressure. Materials with high electrical resistivity are candidates for producing higher Joule heat from the same electric discharge energy. In this Study, the suitability of solid-state Stud Welding for joining steel Studs to steel plates was examined. Steel Studs were successfully joined to steel plates at charged voltages of 125–200 V without distortion of the plate and tarnish marks on the back surface. The joint interface between the projection and plate was arc-shaped. The deformation behavior was notably different from that in previous reports of joining aluminum alloy Studs to aluminum alloy plates or magnesium alloy plates. Observation of the joining area revealed that the projection and plate deformed and spread along the plate surface, squeezing the plate material. The projection and plate deformed more severely as the charged voltage increased. The original shape of the projection tip was partially retained in the joints formed at 125 and 150 V. The amount of martensite observed near the joint interface increased with the charged voltage. The ferrite was not observed above 175 V in the center, and above 150 V inside and outside of the projection near the joint interface. To estimate the maximum temperature reached during joining, the microstructures of the Stud and plate heated at various temperatures were compared with those of joint specimens. Because ferrite and martensite was observed near the joint interface, the maximum temperature reached during joining could be estimated by the presence or absence of the ferrite and martensite. The region where the temperature increased above the A 1 point extended only about 500 μm around the joint interface. Because the majority of the specimen was room temperature and removed heat rapidly from the joint interface, martensite was formed despite the air cooling after joining. The tensile fracture load increased with the charged voltage. The Stud and plate were joined strongly enough for the base plate to fracture partially during the tensile test.
Štefanija Klarić - One of the best experts on this subject based on the ideXlab platform.
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Dr.sc. Marko Dunđer, EWE
2014Co-Authors: Prof. Dr. Sc. Ivan Samardžić, Štefanija Klarić, Strojarski Fakultet Slavonski Brod, Trg I. B. Mažuranić, Sarajevo BihAbstract:The application of on-line monitoring system for recording main Welding parameters during electric arc Stud Welding process at different electric arc stability changes is described in this paper. In the first part of the paper, the basics of electric arc Stud Welding process, and equipment for Stud Welding and process monitoring used in experimental part is described. In the second part of the paper the analysis of process parameters during Welding with purposely induced instabilities is analyzed
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Examination of Welding parameters’ influence on Stud arc Welding process
Pollack Periodica, 2011Co-Authors: Štefanija Klarić, Željko Rosandić, Andrijana MilinovićAbstract:In this paper, the influence of two selected parameters (the Welding time and the presence of the activating flux on the surface of the base metal) on the weld joint at Stud Arc Welding process is investigated. In the experimental part of the paper, the drawn arc Stud Welding process with the ceramic ferrule is applied with the different Welding time and the application of the activating flux for ATIG process. In order to evaluate the influence of the Welding time and the activating flux on the weld characteristics, the cast zone width and Vickers hardness HV 0.2 are measured.
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The influence of Welding parameters on weld characteristics in electric arc Stud Welding
Metalurgija, 2009Co-Authors: Ivan Samardžić, Ivica Kladarić, Štefanija KlarićAbstract:In this paper the influence of Welding parameters on weld geometry during Stud Welding (Drawn Arc Welding process with ceramic ferule) on steel plate and pipe is analyzed as a variation of weld penetration. Also, the changes of weld characteristics are certified trough measurements of HV0, 2 across the weld joint, and analysis of hardened zone.
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Arc Stud Welding process monitoring
2005Co-Authors: Ivan Samardžić, Zvonimir Kolumbić, Štefanija KlarićAbstract:In this paper monitoring, acquisition and data processing of arc Stud Welding process current and voltage is presented. Due to many specifics of this arc Welding process, process stability monitoring is of the great importance. Arc Stud Welding is high efficient Welding process with application in steam boiler production, construction of bridges and in other industry fields. In the experimental part of this paper real time monitoring and acquisition of Welding parameters (Welding current and voltage) was conducted with On-line monitoring system. Stable and unstable arc Stud Welding processes are shown on practical examples. Besides, macro sections of successfully welded joints with arc Stud Welding process and applied Welding parameters are also presented.
D G Hattingh - One of the best experts on this subject based on the ideXlab platform.
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process parameter influence on performance of friction taper Stud welds in aisi 4140 steel
Materials & Design, 2011Co-Authors: D G Hattingh, D L H Bulbring, A Elsbotes, M N JamesAbstract:Abstract Friction taper Stud Welding is a new variant of friction Welding which has been developed from the principles of friction hydro-pillar processing. This paper considers the effect of weld process parameters on weld defects, macrostructure and mechanical properties in AISI 4140 steel. It also presents 3D residual stress data for a typical friction taper Stud weld. Applied downwards force, rotational speed and plunge depth (equivalent to consumable length) of the Stud tool were systematically varied whilst measuring tool torque and temperature at several locations during Welding. A simple Taguchi analysis was then used to relate process parameters and weld tensile strength. The combinations of parameters leading to high tensile strength are identified and linked to the occurrence of specific weld defects.
Fred Gerr - One of the best experts on this subject based on the ideXlab platform.
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comparison of biomechanical loading during use of conventional Stud Welding equipment and an alternate system
Applied Ergonomics, 2011Co-Authors: Nathan B Fethke, Lauren Gant, Fred GerrAbstract:We investigated the effect of an alternative Welding system designed to reduce exposure to extreme trunk flexion on measures of trunk inclination and muscle activity. Among 10 participants, data were collected while using conventional Stud Welding equipment and while using the alternate system. Paired t-tests were used to compare results between the two Welding systems. Mean trunk inclination angle was reduced with the alternate system (34.4° versus 9.7°, p < 0.01). Percent time with trunk inclination angles greater than 60° was also reduced (40.0% versus 4.7%, p < 0.01). In general, the alternate system resulted in less desirable upper trapezius muscle activity levels. The alternate system appears to be effective in reducing exposure to extreme trunk flexion among Stud welders. Continued development of the system should explore features designed to reduce shoulder forces and improve productivity.
