scholarly journals NON-DESTRUCTIVE INSPECTION BY INFRARED THERMOGRAPHY OF RESISTANCE SPOT WELDS USED IN AUTOMOTIVE INDUSTRY

2019 ◽  
Vol 59 (3) ◽  
pp. 238-247 ◽  
Author(s):  
Lucie Forejtová ◽  
Tomáš Zavadil ◽  
Ladislav Kolařík ◽  
Marie Kolaříková ◽  
Jan Sova ◽  
...  
Keyword(s):  
Infrared Thermography ◽  
Automotive Industry ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Destructive Testing ◽  
Factors Affecting ◽  
Resistance Spot ◽  
Constant Delay Time ◽  
Joint Quality ◽  
Non Destructive

Resistance spot welding (RSW) is one of the main joining technologies of thin sheets in the automotive industry. Key factors affecting the strength of the RSW joint are the nugget diameter, asymmetry, expulsions, intended surfaces, and the presence of cracks. Despite its broad use, the RSW joint quality verification is limited only to destructive testing and a limited number of non-destructive testing (NDT) methods. Most of the testing is done destructively by sampling, which assesses only systematic defects. Ultrasonic Testing (UT) is the most used NDT method to detect non-systematic defects in the RSW joints, however the probability of the defect detection of conventional testing techniques is not fully satisfactory. Other approaches were invented to deal with this situation. The article uses the currently most used NDT approach of the UT testing as a benchmark to evaluate the ability of thermographic testing to detect defective welds of the resistance spot welding in an on-line mode. The article demonstrates that the infrared thermography may find systematic process errors that are not detectable by other NDT methods by an analysis of different temperature drops measured after a constant delay time caused by different cooling dynamics of satisfactory and non-satisfactory weld joints.

scholarly journals MULTI-OBJECTIVE OPTIMIZATION OF THE RESISTANCE SPOT-WELDING PROCESS PARAMETERS FOR THE WELDING OF DUAL-PHASE STEEL DP500

2021 ◽  
Vol 55 (2) ◽  
pp. 201-206
Author(s):  
Aleksija Djuric ◽  
Dragan Milčić ◽  
Damjan Klobčar ◽  
Biljana Marković
Keyword(s):  
Automotive Industry ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Dual Phase Steel ◽  
Mechanical Characteristics ◽  
Welding Process ◽  
Dual Phase ◽  
Multi Objective Optimization ◽  
Multi Objective ◽  
Resistance Spot

Resistance spot welding (RSW) is still the most used form of welding in the automotive industry, primarily for welding steel. One of the advanced steels used in the automotive industry is dual-phase steel, so it is important to properly select the welding parameter for these steels. Therefore, this paper presents multi-objective optimization in the RSW welding process of DP 500 steel. The paper considers three different mechanical characteristics i.e., the failure load (F), failure displacement (l) and weld nugget diameter (D), as all these welding characteristics play significant roles in evaluating the quality of spot welding. The results show that the welding current is the most influential parameter with respect to the mechanical characteristics. The effect of welding time on the weld quality is the least significant. The optimal parameters for welding DP 500 steel obtained in this paper are weld current 8 kA, electrode force 4.91 kN and weld time 400 ms.

Non-destructive methodology for parameterization of Burn-Zinc in the resistance spot welding process

2016 ◽  
Vol 31 (4) ◽  
pp. 259-267 ◽  
Author(s):  
Adriane Cássio Baldim ◽  
Sebastião Carlos da Costa ◽  
Thairone Conti Serafini Aguiar
Keyword(s):  
Resistance Spot Welding ◽  
Spot Welding ◽  
Welding Process ◽  
Resistance Spot ◽  
Non Destructive

Study on Nonlinear Multiple Regression Modeling of Nugget Morphology for Unequal-Thickness Dissimilar Steel Welding

2011 ◽  
Vol 189-193 ◽  
pp. 3300-3308
Author(s):  
Yi Luo ◽  
Chang Hua Du ◽  
Chun Tian Li ◽  
Jin He Liu
Keyword(s):  
Multiple Regression ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Welding Process ◽  
Welding Current ◽  
Current Electrode ◽  
Factors Affecting ◽  
Dissimilar Steel ◽  
Resistance Spot ◽  
Multiple Regression Modeling

The special thermal effect makes some alterations to nugget morphology during resistance spot welding on unequal-thickness dissimilar steel. Method of nonlinear multiple orthogonal regression assembling design was introduced to design the experiment and investigate the resistance spot welding process. The indexes studied in experiments were nugget diameter and nugget deviation, which were the primary factors affecting the nugget morphology. Furthermore, four process parameters, namely welding current, electrode force, welding current duration and heat-treatment pulse current, and interactions among them were considered as the factors impacting the indexes. The nonlinear multiple regression models about nugget morphology parameters were developed on the basis of optimization. The experimental results showed that there was an effective prediction on nugget size based on the optimized models. The optimization to welding process also can be realized by the analysis to the effects of parameters and interactions.

Effect of Electrode Force on Expulsion in Resistance Spot Welding with Initial Gap

2011 ◽  
Vol 675-677 ◽  
pp. 795-798 ◽  
Author(s):  
Jie Shen ◽  
Yan Song Zhang ◽  
Xin Min Lai
Keyword(s):  
Resistance Spot Welding ◽  
Spot Welding ◽  
Sheet Thickness ◽  
Carbon Steels ◽  
Dual Phase ◽  
Low Carbon ◽  
Resistance Spot ◽  
Steel Sheets ◽  
Electrode Force ◽  
Joint Quality

Compared with the conventional low carbon steels, the expulsion is more prone to occur in resistance spot welding (RSW) of dual phase (DP) steels. Especially when the initial gap exists between the steel sheets, the weld expulsion would reduce the weld quality of the joint. It is important to decrease or inhibit the occurrence of the weld expulsion in auto-body assembly line in order to guarantee the joint quality. In this study, the experiments of RSW with different initial gaps have been done to study the effect of the electrode force on the expulsion using different thicknesses of dual phase steels. The results show that the increment of the electrode fore would enable to decrease the occurrence of expulsion with the increase of the sheet thickness and gap spacing in resistance spot welding of DP steel sheets.

Forging force in resistance spot welding

2002 ◽  
Vol 216 (7) ◽  
pp. 957-968 ◽  
Author(s):  
H Tang ◽  
W Hou ◽  
S J Hu
Keyword(s):  
Automotive Industry ◽  
Electrical Resistance ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Weld Quality ◽  
Resistance Spot ◽  
Force Application ◽  
Force Increase ◽  
Forging Force ◽  
Analytical Approaches

This paper studies an intentional force increase during the process of resistance spot welding (RSW). Known for decades, the forging force as a way of influencing weld quality has rarely been applied in the automotive industry. There has been little research in this area. In this paper, the effects of varying forging force are investigated using both experimental and analytical approaches. Through the analysis of dynamic electrical resistance, the mechanism of the forging effects is explored. This study achieves a better understanding of forging force application and shows the benefits of the forging force on weld quality.

Sign in / Sign up

Export Citation Format

Share Document