Experimental investigation on resistance spot welding of dissimilar weld joints
01 Apr 2021-Vol. 235, Iss: 2, pp 505-513
TL;DR: In this paper, galvanized high strength interstitial free (HIF) steel sheets and dual phase (DP780) steel sheet were used for the investigations, and resistance spot weld joints were fabricated.
Abstract: In the present study, galvanized High Strength Interstitial Free (HIF) steel sheets, and Dual Phase (DP780) steel sheets were used for the investigations. Resistance spot weld joints were fabricate...
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TL;DR: In this article, the diversification in metallurgical transformation under solution treatment is emphasized, which governs the solidification rate and can trigger the final mechanical be-ing of the metal.
Abstract: The current experimentation emphasises on the diversification in metallurgical transformation under solution treatment, which governs the solidification rate and can trigger the final mechanical be...
3 citations
15 Jun 2023-Proceedings Of The Institution Of Mechanical Engineers, Part E: Journal Of Process Mechanical Engineering
TL;DR: In this paper , the effects of different welding parameters on microhardness, nugget diameter, tensile shear force, and failure mode were investigated, and a linear relationship was determined between the nigget diameter and tensile hear force.
Abstract: Resistance spot welding was implemented to unalloyed steel produced by powder metallurgy method at different welding parameters in this study. Other welding parameters are constant, but electrode force values are 0.21–0.28–0.35 kN and welding current values are 9–10–11 kA. The effects of different welding parameters on microhardness, nugget diameter, tensile shear force, and failure mode were investigated. Consequently, the tensile shear force increased as welding current and electrode force up to a certain value increased. When critical electrode force value was exceeded, tensile shear force decreased, although nugget diameter increased. Compared to the base material, a decrease in tensile shear force has occurred in resistance spot welded joints. Except for values higher than the critical electrode force value, a linear relationship was determined between the nugget diameter, tensile shear force, and microhardness. Two different failure modes were observed, namely sheet transverse failure and partial interfacial failure.
03 Apr 2023-Proceedings Of The Institution Of Mechanical Engineers, Part E: Journal Of Process Mechanical Engineering
TL;DR: In this article , different resistance spot welding joints were made on DC01 steel with welding parameters of 8-10-12-kA welding currents and 1.96-2.94 kN electrode forces.
Abstract: In this study, different resistance spot welding joints were made on DC01 steel with welding parameters of 8–10–12 kA welding currents and 1.96–2.94 kN electrode forces. Measurements of the nugget diameter and tests of the tensile shear were performed. Also, various failure modes were determined. The importance of welding parameters on the value of the tensile shear force was determined, and a statistical model was established with the ANOVA study. The microstructure of the joint was characterized by optical and scanning electron microscopes. As a result, the nugget diameter and the tensile shear force were increased with an increase in the welding current and the electrode force. Two failure modes, namely, interfacial and plug failures, were observed. The effect of the electrode force was higher than the welding current on the tensile shear force. The base material was densely composed of the ferrite phase, heat-affected, and the fusion zone consisted of the coarse ferrite phase.
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TL;DR: In this paper, the change of welding current and electrode voltage in the secondary circuit was monitored in real-time, and the variation of the dynamic resistance was obtained across electrodes and analyzed to characterize the nugget growth.
30 citations
"Experimental investigation on resis..." refers background in this paper
...Luo et al.22 noticed the similar behavior for resistance spot welding of Q235 steels sheets....
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...Luo et al.(22) noticed the similar behavior for resistance spot welding of Q235 steels sheets....
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TL;DR: In this paper, the effect of welding parameters, namely, welding current and welding time, on resistance spot welding (RSW) of the AISI 316L austenitic stainless steel sheets was precisely considered.
Abstract: This article aims at investigating the effect of welding parameters, namely, welding current and welding time, on resistance spot welding (RSW) of the AISI 316L austenitic stainless steel sheets. The influence of welding current and welding time on the weld properties including the weld nugget diameter or fusion zone, tensile-shear load-bearing capacity of welded materials, failure modes, energy absorption, and microstructure of welded nuggets was precisely considered. Microstructural studies and mechanical properties showed that the region between interfacial to pullout mode transition and expulsion limit is defined as the optimum welding condition. Electron microscopic studies indicated different types of delta ferrite in welded nuggets including skeletal, acicular, and lathy delta ferrite morphologies as a result of nonequilibrium phases, which can be attributed to a fast cooling rate in the RSW process. These morphologies were explained based on Shaeffler, WRC-1992, and pseudo-binary phase diagrams. The optimum microstructure and mechanical properties were achieved with 8-kA welding current and 4-cycle welding time in which maximum tensile-shear load-bearing capacity or peak load of the welded materials was obtained at 8070 N, and the failure mode took place as button pullout with tearing from the base metal. Finally, fracture surface studies indicated that elongated dimples appeared on the surface as a result of ductile fracture in the sample welded in the optimum welding condition.
25 citations
TL;DR: In this paper, the electric resistance spot welding process has been applied to dual-phase (DP 600 type) steel sheets and the microstructure and hardness of spot welded joint samples have also been studied andrecommendations were given to users showing the optimum welding parameters.
Abstract: In this study, the electric resistance spot welding process has been applied to dual-phase (DP 600 type) steel sheets. Spot welding parameters, namely, electrode form, electrode material, and electrode force were stayed constant, and welding current and welding time have been changed to detect the optimum welding parameters for maximum joint strength. The sample welded joints have been carried out as 1.0 mm--1.0 mm, 1.2 mm--1.2 mm, and 1.0 mm--1.2 mm in three different thickness combinations in 4, 5, 6, 7, and 8 kA welding currents and 5, 10, 15, 20, and 25 cycles welding times. The strengths of the joints under uniaxial tensile-shear and tensile-peel loading have been studied and compared with the conventional spot welds of maximum joint strength for similar thickness steel sheets. The microstructure and hardness of spot welded joint samples have also been studied andrecommendations were given to users showing the optimum welding parameters.
23 citations
TL;DR: In this article, microstructures of the different zones of spot welded interstitial free steels have been characterised by optical, scanning electron and transmission electron microscopes, and microstructural changes at weld and heat affected zone have also been correlated with welding heat input and microhardness values.
Abstract: Interstitial free (IF) steels having excellent drawing and forming characteristics find extensive use in autobody panels. Although, resistance spot welded joints are widely used in the automobile industry, little is known about the metallurgical changes which occur during the spot welding process. The investigation of the metallurgical changes is very important for the safety strength of the welded joints. In the present research work, microstructures of the different zones of spot welded interstitial free steels have been characterised by optical, scanning electron and transmission electron microscopes. Microstructural changes at weld and heat affected zone have also been correlated with welding heat input and microhardness values.
13 citations
TL;DR: In this article, the effect of dynamic contact resistance (DCR) during MFDC spot welding of dual phase and martensitic steels was evaluated, and a comparative analysis of DP590 to DP590 with DP780 to DP780 steel welds was carried out.
Abstract: The effect of dynamic contact resistance (DCR) during MFDC spot welding of dual phase and martensitic steels was evaluated. A comparative analysis of DP590 to DP590 with DP780 to DP780 steel welds, and DP780 to DP780 with M1200 to M1200 steels welds was carried out. The DCR of DP780 steel is higher than DP590 steel during the initial stages of weld time, but is reversed later. The bulk resistance component, which is higher in DP780 steel, is dominant and generates more energy early in the process and controls melting. Although the total energy input is almost same, the higher β-peak and its early occurrence ensures better heat utilisation resulting in larger nugget size. Contrarily, in martensitic steel the interface resistance component remains high throughout the entire welding process and compensates for the lower bulk resistance effect. Even with relatively lower energy input the nuggets produced in M1200 steel are comparable to DP780 steel.
13 citations
"Experimental investigation on resis..." refers background in this paper
...The authors found that the dynamic resistance (DR) values of DP780 steel weld joints are higher as compared to the DP590 weld joints at the initial stages in the weld cycle but the trend was reversed later.(7) The automotive industry uses various kinds of steel materials to fabricate the body of car....
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