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.
References
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15 Nov 2011-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper, the authors investigated and analyzed the transition between interfacial and pull-out failure modes in AHSS resistance spot welds during the tensile-shear test by the use of analytical approach.
Abstract: Failure mode of resistance spot welds is a qualitative indicator of weld performance. Two major types of spot weld failure are pull-out and interfacial fracture. Interfacial failure, which typically results in reduced energy absorption capability, is considered unsatisfactory and industry standards are often designed to avoid this occurrence. Advanced High Strength Steel (AHSS) spot welds exhibit high tendency to fail in interfacial failure mode. Sizing of spot welds based on the conventional recommendation of 4t0.5 (t is sheet thickness) does not guarantee the pullout failure mode in many cases of AHSS spot welds. Therefore, a new weld quality criterion should be found for AHSS resistance spot welds to guarantee pull-out failure. The aim of this paper is to investigate and analyze the transition between interfacial and pull-out failure modes in AHSS resistance spot welds during the tensile–shear test by the use of analytical approach. In this work, in the light of failure mechanism, a simple analytical model is presented for estimating the critical fusion zone size to prevent interfacial fracture. According to this model, the hardness ratio of fusion zone to pull-out failure location and the volume fraction of voids in fusion zone are the key metallurgical factors governing type of failure mode of AHSS spot welds during the tensile–shear test. Low hardness ratio and high susceptibility to form shrinkage voids in the case of AHSS spot welds appear to be the two primary causes for their high tendency to fail in interfacial mode.
162 citations
15 Nov 2011-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this article, the authors investigated and analyzed the transition criteria from interfacial to pullout failure mode in AHSS resistance spot welds during the tensile-shear test by the use of both experimental and analytical approaches.
Abstract: The objective of this paper is to investigate and analyze the transition criteria from interfacial to pullout failure mode in AHSS resistance spot welds during the tensile-shear test by the use of both experimental and analytical approaches. Spot welds were made on three dual phase steel grades including DP600, DP780 and DP980. A low strength drawing quality special killed (DQSK) steel and AISI 304 austenitic stainless steel were also tested as a baseline for comparison. The microstructure and mechanical strength of the welds were characterized using metallographic techniques and the tensile-shear testing. Correlations among critical fusion zone (FZ) size required to ensure the pullout failure mode, weld microstructure and weld hardness characteristics were developed. It was found that critical FZ size increases in the order of DQSK, DP600, DP980, DP780 and AISI304. No direct relationship was found between the tensile strength of the base metal and the critical FZ size. It was concluded that low hardness ratio of FZ to pullout failure location and high susceptibility to form shrinkage voids are two primary reasons for high tendency of AHSS to fail in interfacial mode. HAZ softening can improve RSW mechanical performance in terms of load bearing capacity and energy absorption capability. This phenomenon promotes PF mode at smaller FZ sizes. This fact can explain smaller critical FZ size measured for DP980 in comparison with DP780. The results obtained from the model were compared to the experimental results and the literature and a reasonable agreement was obtained.
99 citations
TL;DR: A 2D axisymmetric electro-thermo-mechanical finite element (FE) model was developed to study the effect of welding time and current intensity on nugget size in resistance spot welding process of AISI type 304L austenitic stainless steel sheets using ANSYS commercial software package.
94 citations
"Experimental investigation on resis..." refers result in this paper
...Previous study observed a similar trend for nugget size reduction for austenitic stainless steel.(26)...
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Journal Article•
TL;DR: In this paper, the weld nugget in resistance spot welding of Type 347 stainless steel was found, using finite element methods, to initiate in a ring shape at a distance from the electrode center.
Abstract: The weld nugget in resistance spot welding of Type 347 stainless steel was found, using f inite element methods, to initiate in a ring shape at a distance from the electrode center. The ring-like weld nugget expands inward and outward during the welding cycles. The welding current, electrode pressure and hold time affected the thermomechanical interactions of the welding process and changed the f inal nugget geometry. Also, when spot welding workpieces of unequal thicknesses, it was found that the weld nugget formed mostly in the thicker workpiece than in the thinner workpiece, and when spot welding dissimilar materials, the weld nugget formed more in the workpiece of lower thermal conductivity or higher electrical resistivity.
92 citations
"Experimental investigation on resis..." refers background in this paper
...Previous study reveals that subsequent range of welding current (5–8 kA) noticed for the resistance spot weld of type 347 SS & AISI 1045 specimen having 1mm thickness.(21) Figure 5 represents the subsequent comparison of dynamic resistance (DR) curves with that of various...
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Journal Article•
TL;DR: In this paper, a parametric study was carried out on a Gleeble® machine, investigating the influence on the contact resistance of interface normal pressure, temperature, and base metal.
Abstract: Electrical contact resistance is of critical importance in resistance welding. In this article, the contact resistance is experimentally investigated for welding mild steel, stainless steel, and aluminum to themselves. A parametric study was carried out on a Gleeble® machine, investigating the influence on the contact resistance of interface normal pressure, temperature, and base metal.
71 citations
"Experimental investigation on resis..." refers background in this paper
...the DR with rise of electrode force for different materials.(23) Therefore from Figures 5 to 7 it can be con-...
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