scholarly journals Experimental and numerical analysis of shunting effect in resistance spot welding of Al2219 sheets

2016 ◽  
Vol 64 (2) ◽  
pp. 425-434 ◽  
Author(s):  
M. Jafari Vardanjani ◽  
A. Araee ◽  
J. Senkara ◽  
J. Jakubowski ◽  
J. Godek
Keyword(s):  
Finite Element ◽  
Heat Affected Zone ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Numerical Solutions ◽  
Potential Temperature ◽  
Model Verification ◽  
Spot Welds ◽  
Resistance Spot ◽  
Shunting Effect

Abstract Few aspects of shunting effect have been studied so far. Shunting effect in resistance spot welding (RSW) occurs when the electrical current passes through the previous spot welds. Value of this current depends mostly on distance, number, and size of previous spot welds. This will cause some dimensional and metallurgical changes in welding nugget as well as heat affected zone (HAZ). In this study, shunting effect of RSW is considered by finite element method (FEM) and the results are compared to experiments performed on aluminum alloy 2219. Weld spacing together with welding current and time are considered to discover the effect of shunting current in the final quality of nugget. A three factor experiment design has been performed to find the significance of factors and interactive effects, as well as finite element model verification. Electrothermal and mechanical interactions are considered in the FEM. Experimental and numerical solutions have yielded similar results in terms of welding nugget properties. Asymmetry in electrical potential, temperature, stress distribution and geometry of shunted nugget is predicted and verified directly or indirectly. Intense effect of shunting current on nugget height, asymmetric growth of heat affected zone (HAZ) toward previous welding nugget, as well as concentration of alloying elements along grain boundaries are also discovered.

Consideration of micro-finite element model for multiscale resistance spot welding analysis

2017 ◽  
Vol 2017.30 (0) ◽  
pp. 292
Author(s):  
Hiroyuki Kuramae ◽  
Tomoya Niho ◽  
Hirochika Aramaki ◽  
Kengo Oya ◽  
Tomoyoshi Horie
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Element Model ◽  
Resistance Spot

Resistance Spot Welding of Low Carbon Steel to Austenitic CrNi Stainless Steel

2014 ◽  
Vol 875-877 ◽  
pp. 1499-1502 ◽  
Author(s):  
Ladislav Kolařík ◽  
Miroslav Sahul ◽  
Marie Kolaříková ◽  
Martin Sahul ◽  
Milan Turňa
Keyword(s):  
Stainless Steel ◽  
Carbon Steel ◽  
Weld Joint ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Spot Welds ◽  
Resistance Spot ◽  
Resistance Spot Welds

The contribution deals with resistance spot welding of low carbon steel to austenitic CrNi stainless steel. The thickness of welded dissimilar steels was 2 mm. DeltaSpot welding gun with process tape was utilized for welding of the above-mentioned combination of steels. Resistance spot welds were produced under different welding currents. The welding currents used were 7 kA, 7.5 kA and 8 kA, respectively. Optical microscopy, microhardness measurement across the weld joint and EDX analysis across the weld joint interface were used to evaluate the quality of resistance spot welds of dissimilar steels.

scholarly journals Optimization of resistance spot welding parameters for microalloyed steel sheets

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Ján Viňáš ◽  
Ľuboš Kaščák ◽  
Miroslav Greš
Keyword(s):  
Bearing Capacity ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Microalloyed Steel ◽  
Welding Time ◽  
Spot Welds ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Resistance Spot ◽  
Steel Sheets

Abstract The paper presents the results of resistance spot welding of hot-dip galvanized microalloyed steel sheets used in car body production. The spot welds were made with various welding currents and welding time values, but with a constant pressing force of welding electrodes. The welding current and welding time are the dominant characteristics in spot welding that affect the quality of spot welds, as well as their dimensions and load-bearing capacity. The load-bearing capacity of welded joints was evaluated by tensile test according to STN 05 1122 standard and dimensions and inner defects were evaluated by metallographic analysis by light optical microscope. Thewelding parameters of investigated microalloyed steel sheets were optimized for resistance spot welding on the pneumatic welding machine BPK 20.

scholarly journals ANALYSIS OF SPOT WELDING ELECTRODE

2013 ◽  
pp. 263-268
Author(s):  
RAJANARENDER REDDY PINGILI
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
The Other ◽  
Element Analysis ◽  
Resistance Spot ◽  
Electrode Shape ◽  
The Finite Element Analysis ◽  
Welding Electrode

Electric resistance spot welding has been extensively used for many years in the automotive and aerospace industry for joining body sheet components. Compared to other welding processes such as arc welding process, resistance spot welding is fast, easily automated and easily maintained. Accurate thermal analysis of spot welding electrode could permit critical design parameters to be identified for improved electrode life. It is a complex process where coupled interactions exist between electrical, thermal and mechanical phenomena. On the other hand, finite element method (FEM), which can deal with nonlinear behaviors and complex boundary conditions, provides a powerful tool for studying these interactions and has become the most important method for the analysis of resistance spot welding. In this study, a 2-D finite element model has been developed to predict the transient thermal behavior of spot welding electrodes. The model included heat transfer analysis, electrical field analysis and phase change during melting or solidification and temperature dependant material properties, and also their inter-dependence. The contacts at faying surface and at electrode – work interface, with temperature dependant contact resistances were modeled. Three types of electrode shapes – flat, pointed and dome nose were analyzed. Temperature distribution on each electrode shape was obtained from the finite element analysis. Maximum temperature of 2876 ºC was observed in dome nose electrode in 0.2 seconds of welding time. Dome nose electrode requires a minimum weld time of all the other electrode shapes to get the required nugget size, resulting in the least power consumption. Nugget size was predicted for each electrode shape. Experimental results obtained were in good agreement with the finite element analysis results.

scholarly journals Adaptive Resistance Spot Welding Process that Reduces the Shunting Effect for Automotive High-Strength Steels

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 775 ◽  
Author(s):  
Jiyoung Yu
Keyword(s):  
Heat Input ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Welding Process ◽  
Vehicle Body ◽  
Logistic Growth ◽  
Power Curve ◽  
Resistance Spot ◽  
Welding Heat Input ◽  
Shunting Effect

Although short-pitch resistance spot welding (RSW) significantly increases vehicle body strength, its application has been limited because of the associated shunting effect. In this study, a reference-based adaptive RSW process intended to minimize the shunting effect was proposed, and a related RSW system that controls welding current and power was developed to implement the adaptive method. The proposed RSW method compensates for the heat input loss caused by the shunting effect based on the estimated weld pitch and reference data obtained under suitable welding conditions. An exponential model was developed using a unique indicator (i.e., the ratio of the adaptive welding heat input to the reference welding heat input until the reference welding power curve peak) to estimate the weld pitch. A logistic growth model was next developed based on the relationship of the nugget diameter, heat input, and weld pitch to estimate the heat input compensation. A unique strategy using power control with a modified reference power curve was applied to supply the calculated heat input compensation. The experimental results intended to validate the proposed adaptive RSW process indicated that the proposed process effectively reduced the shunting effect and produced an improved nugget shape relative to the conventional RSW process.

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