Stud Welding Research Articles

An Experimental Assessment and Numerical Simulation of the Corrosion Behavior of Aluminum Welded Joints in Diverse Environments

The corrosion behavior of stud-welded AA5083-H321/AA6061-T6 joints was examined. The electrochemical demeanor of the resultant joint was scrutinized in 3.5% NaCl, ASTM seawater, and Na2SO4 solutions using scanning electron microscopy (SEM), optical microscopy (OM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). COMSOL Multiphysics version 5.6 software was used to predict the galvanic corrosion of AA5083-H321/A6061-T6 in different solutions, using the software finite element (FE) kit. The results indicated that drawn arc stud welding (DASW) enhanced the corrosion resistance of the welding zone, with the highest resistance observed in the Na2SO4 solution. This process also influenced the pitting corrosion rate and minimized alterations in pit morphology, with the order of corrosion resistance decreasing from Na2SO4 to 3.5% NaCl and ASTM seawater. Among the base metals, the AA6061-T6 side of the weld exhibited superior corrosion resistance compared to the AA5083-H321 side across all tested solutions. The results from the numerical simulation of the corrosion behavior of the welded joint support the experimental assessment.

Application of gray relational analysis for optimizing stud welding parameters of IF 7114 steel for the automotive industry

In this study, the application of stud welding to IF 7114 steel sheets in the automotive industry using stainless steel and copper-plated steel studs with different diameters and welding voltages was investigated. The aim is to optimize welding parameters and investigate their effects on the mechanical properties of the weld zone. Taguchi optimization and gray relational analysis were used to identify the best welding parameters for tensile strength and torque resistance. Results showed that the highest tensile strength and torque resistance were achieved with a stainless steel M8 stud diameter and 150 V welding voltage, while the lowest values were observed with copper-plated steel M5 studs and 180 V voltage. Additionally, stainless steel studs consistently outperformed copper-plated steel in both tensile strength and torque resistance. The study concludes that stainless steel studs, particularly with an M8 diameter at 180 V, offer the most favorable welding performance.

Investigation of the electrical quality and long-term stability of aluminum ground stud connections in automotive applications

Investigation of the electrical quality and long-term stability of aluminum ground stud connections in automotive applications

Investigation on the Effect of Projection Types on Stud Weld Strength by Taguchi Method

In this study, the effect of different weld projections on the mechanical properties of stud welds was analyzed using the Taguchi experiment planning method, using a projection welding machine with a capacity of 100 kVA with MFDC transformer. The samples were subjected to the tensile rupture force test with a destructive test device. The aim of this study was to ensure product safety by capturing the spot-welding quality, which is determined by the specifications of the automotive main industry, using a bolt with a lower weight. In this study, 1.5 mm WSS-M1A365-A11 uncoated steel sheet and 8.8 quality M6x1.00x25 triple projection uncoated welding bolts and 8.8 quality M6x1.00x18.5 ring shaped weld bolts were used as stud welding bolts. Different welding times, different welding currents and different welding clamping forces were used on the WSS-M1A365-A11 steel sheet samples in the stud welding operation with bolts. Taguchi analysis showed that ring shaped stud weld bolts required welding parameters of 32 ms welding time, 27 kA welding current and 500 daN welding force, while triple projection stud welding was found to perform the best optimum weld with 23 ms welding time, 18 kA welding current and 350 daN force.

Fatigue strength of repair‐welded headed studs

AbstractWelded connections of headed studs are highly stressed details in bridge structures in steel‐concrete composite construction and are largely responsible for the functionality of the supporting structures. At the same time, this detail requires a lot of resources due to the high welding effort and therefore has a major influence on the economic success. An important criterion for the economic and ecological balance of the structure is the durability of the welded joint, which is quantified by the fatigue strength. The welding of headed studs for composite bridges is usually carried out using fully mechanised drawn arc stud welding in accordance with EN ISO 14555. Due to the process, stud welds that do not fulfil the standard requirements for flawless condition may occur in individual cases. The design rules for stud load‐bearing capacity in accordance with EN 1994‐2 are based on tests and only apply to connections produced using drawn arc stud welding. In the past, there were practicable and tacitly accepted solutions for repairing such sporadically occurring faulty welds, but these were never systematically investigated. Particularly against the background of fatigue loading, repair‐welded stud connections are now to be systematically investigated in a project funded by the AIF. The article provides an overview of the execution of stud welded joints and presents the tests planned in the project in order to achieve a practicable recommendation for the repair welding of headed studs.

THE EFFECT OF ARC STUD WELDING PARAMETERS ON MECHANICAL PROPERTIES OF DOCOL 1500M ADVANCED HIGH STRENGTH STEEL WELDING JOINTS

Arc stud welding method is a welding method that takes advantage of the arc's ability to melt metals. Stud welding is an easy and fast welding method that is generally applied to surfaces where threading is problematic and welding is difficult. Docol 1500 martensite materials are high-strength steels with high tensile strength up to 1700 MPa and good ductility. These type of materials provide high efficiency, especially in the automotive industry, in terms of both vehicle lightness and advanced crash protection. In this study, the weldability of threaded studs made of 20MnB4 grade carbon steel was investigated using the arc stud welding process on Docol 1500M plate. The arc stud welding process was carried out using a ceramic ferrule at different combination values with electric current values ranging between 300A and 500A and different welding times ranging from 0.125 seconds to 0.300 seconds, as well as variable welding parameters such as 3mm plunge value and 5.9mm lift distance. With the experimental study, the most suitable welding parameters were try to determined according to the size and properties of the materials to obtain a quality welded. At the end of welding process, the effects of arc stud welding parameters such as welding current, welding time, plunge and lifting distance on mechanical and microstructural properties were experimentally investigated.

Comparative Study of Friction Stir, Stud and Seam Welding of Aluminium Alloys Using Different Grades

Friction stud welding is an innovative and efficient welding process used to create strong and reliable bonds between studs or fasteners and workpieces, particularly in applications where rapid and secure fastening is critical. This welding technique involves generating friction and heat between the stud and workpiece to forge a strong joint. The process consists of several key steps, including preparation, rotation, weld formation, and cooling. Friction stud welding offers numerous advantages, such as speed, consistency, minimal distortion, and the elimination of the need for additional filler materials. It is widely employed in various industries, including construction, automotive, and aerospace, for applications ranging from structural steel connections to automotive component assembly. However, successful friction stud welding necessitates careful selection of materials, welding parameters, and skilled operators to ensure durable and dependable welded joints. This abstract provides a concise overview of the friction stud welding process and its essential features.

Sleeve friction stud welding towards formation and property

Sleeve friction stud welding towards formation and property

Shear resistance of welded studs in deck slab ribs transverse to beams

Shear resistance of welded studs in deck slab ribs transverse to beams

Total Focusing (TFM) for the Ultrasonic Testing (UT) of drawn arc stud welding

This article describes the results obtained applying ultrasonic testing (UT) with phased arrays (PAUT) using full matrix capture (FMC) and total focusing method (TFM) for the inspection of drawn arc stud welding. Weld studs are usually directly applied on the top of a metal slab using a dedicated welding gun. This procedure involves heating the end tip of the stud using a strong electric arc created by a positive electric current. This welding procedure shall comply to various normative requirements, but on the other side there is not a clear reference to any applicable non-destructive method (NDT) to control the quality of the weld seam. Shear connectors are normally used in concrete/steel composite structures to allow the combined action of the concrete slab and the steel profile thereby increasing both the stiffness and strength of the structure. Flaws in this connection would result in severe bending and cracking of the entire structure. This article proposes an advanced UT method to inspect the weld between shear connections and metal slab using FMC. Data acquired with FMC are processed by TFM algorithms improving image resolution, signal to noise performances and allowing 3D data imaging. The combined use of PAUT searching units and signal processing with high resolution measurement shows a great potential in industrial NDT applied to civil engineering, resulting in a more effective, reliable, and faster inspection methodology than many other methods, such as radiographic testing (RT).

Effect of a longitudinal magnetic field on arc motion and joint structure of a hollow stud

Given the non-uniform melting of the end face of a joint and the local non-fusion of the joint in large-diameter hollow stud welding, to research the law of arc motion, the joint-forming quality, weld microstructure and mechanical properties in the process of hollow stud welding propelled by a longitudinal magnetic field were investigated in this study. The results reveal that under the influence of a longitudinal magnetic field, the arc on the end of a stud is affected by the Lorentz force and spirals downward. In the welding process, with an increase in magnetic field intensity, the arc uniformly burns the stud end face, preventing local non-fusion and resulting in a well-shaped joint. Under the action of magnetic field stirring, eutectoid ferrite is broken, the content of eutectoid ferrite and bainite is diminished, the nucleation barrier is reduced and the grain is refined. Under the action of a longitudinal magnetic field, the shear strength of the hollow stud welded joint rises to 312 MPa, surpassing the strength of a joint welded without a magnetic field.

INVESTIGATION OF FRICTION PRESSURE EFFECT ON WELDING QUALITY IN FRICTION STUD WELDING PROCESS

The influence of friction pressure on welding quality when friction stud welding 1017 low carbon steel with AISI 304 austenitic stainless steel is investigated in this study. friction stud welding is employed in industrial applications instead of conventional welding processes Due to the friction welding process didn't need to reach the melting point of welded metals. Welding is performed on these dissimilar metals by utilizing a lathe machine with a load cell connected to a weight indicator and a manufacturing grip to fasten the plate at a rotating speed of 1600 RPM, a friction time of 20 seconds, and a friction pressure of (15, 20, and 25) MPa. After the welding procedure is completed, the specimens are subjected to tensile, torque, and hardness tests to evaluate the welding quality. In addition, optical microscope research was carried out to determine the microstructural aspects. The effect of friction pressure on welding quality was investigated based on the information generated from the results. The increase of friction pressure during the process from 15 MPa to 25 MPa leads to an increasing ultimate tensile strength from 203 MPa to 210 MPa approximately. Also, the torque values raised from 179 N.m to 198 N.m in the same case.

Weld morphology and grain growth characteristics of driven moving arc hollow stud welding

Weld morphology and grain growth characteristics of driven moving arc hollow stud welding

Characterization of galvanized steel-low alloy steel arc stud welded joint

This paper investigates the possibility of successfully welding a Low Alloy Steel (LAS) stud to Galvanized Steel (GS) plate.Arc Stud Welding (ASW) was performed on joining LAS studs to GS plates. Welding parameters were selected based on weld trails. The first tests of the welded joints were based on visual inspection for welding defects such as lack of fusion and undercut welding defects. The good quality should be free of these defects and have full weld reinforcement. Other weld qualifications included torque strength test, microhardness test, and microstructure examination.The LAS studs have been successfully welded to a galvanized steel plate using the arc stud welding process. Higher welding current with adjusted welding time (800 A, 0.3 s) gave full weld reinforcement, the best joint appearance, and strength. Martensite phase was detected in the weld area and heat affected zone (HAZ), affecting the joint mechanical properties. Hardness property varied across the welded joint, and maximum hardness was recorded at the HAZ at the stud side. Hardness increased with the increasing welding current. At 800 A, welding current hardness was 10% higher than at 400 and 600 A. Torque strength was affected by weld reinforcement, and 800 A gave the best weld reinforcement that produced the highest torque strength.The main research limitation is the difficulty of welding LAS studs and GS plates. In conventional welding methods, such as gas metal arc welding, it is hard to get full weld penetration due to the geometry restrictions of the joint, which results in partial weld penetration between the studs and the plates. Furthermore, the issue of zinc evaporation during welding can be reduced by the advantage of the very high welding speed (in milliseconds) of ASW that overcomes the problem of continuous welding that usually results in the formation of harmful porosities and poor weldability.In this research, galvanized steel plates were successfully welded to LAS studs using the ASW process. The welding parameters for this dissimilar welding joint were carefully selected. Microstructure changing due to the welding process was investigated. The joint mechanical properties were evaluated.

Explainable Models for Multivariate Time-series Defect Classification of Arc Stud Welding

Arc Stud Welding (ASW) is widely used in many industries such as automotive and shipbuilding and is employed in building and jointing large-scale structures. While defective or imperfect welds rarely occur in production, even a single low-quality stud weld is the reason for scrapping the entire structure, financial loss and wasting time. Preventive machine learning-based solutions can be leveraged to minimize the loss. However, these approaches only provide predictions rather than demonstrating insights for characterizing defects and root cause analysis. In this work, an investigation on defect detection and classification to diagnose the possible leading causes of low-quality defects is proposed. Moreover, an explainable model to describe network predictions is explored. Initially, a dataset of multi-variate time-series of ASW utilizing measurement sensors in an experimental environment is generated. Next, a set of pre-possessing techniques are assessed. Finally, classification models are optimized by Bayesian black-box optimization methods to maximize their performance. Our best approach reaches an F1-score of 0.84 on the test set. Furthermore, an explainable model is employed to provide interpretations on per class feature attention of the model to extract sensor measurement contribution in detecting defects as well as its time attention.

Special Issue on Advanced Diagnostics and Prognostics for Automotive Systems

This special issue on Advanced Diagnostics and Prognostics for Automotive Systems provides an opportunity to discuss recent advances in different topics related to modern automotive systems. The topics include model-based monitoring algorithm for diesel vehicle aftertreatment system, air-path health management strategy for estimation of the mass flows and mitigation of the air-path faults, early detection of anomalies in fuel system evaporative and purge systems leveraging vehicles connectivity, review of intelligent maintenance of EVs at both component level and system level to identify existing gaps in EVs DnP, detection and isolation of ground connection faults in electronic control units, root cause detection of defects in arc stud welding that is used to join automotive structures, machine learning based anomaly detection framework demonstrated on the hydraulic system of electric off-road vehicles, and signal abstraction to assist fast root-cause detection of large scale control systems.

Evaluation of hardness and impact toughness of drawn arc stud weldments on different structural steel grades

The drawn arc stud welding (DASW) procedure is usually qualified by visual examinations and practical destructive tests of the joint according to international standards. An assessment of the material properties in specific weld zone regions is not requested under consideration of their limited areas or the general joint dimension although the press welding process implies a complex metallurgy. Nonetheless, there is a need of knowledge regarding the heterogeneous material properties in the weld zone, especially when welding on base materials with specified strength and toughness behavior that might be significantly diminished. In this study, the local strength and toughness properties in welded joints of non-alloyed steel studs (Ø20 mm) on plates of different generic structural steel grades are investigated by hardness test and Charpy impact testing. A non-alloyed normalized structural steel (nominal yield strength 355 MPa) and a thermomechanically rolled fine grain structural steel of same strength as well as a quenched and tempered structural steel with high nominal yield strength of 690 MPa were examined. In the weld metal region, relatively similar hardness and low impact energy were determined despite of the different base plate steel grades. The base plate heat-affected zones suffer a strong embrittlement due to the DASW thermocycle.

Development of a science-based technology for the manufacture of sheet panels with fasteners

An analysis was made of the application of Stud Welding hardware welding technologies depending on the welded structures used, the duration of the process, the shape of the stud butt and the consumables used. The use of CD Stud Welding technology for welding metalware to thin-sheet panels is substantiated. The essence of the process of formation of a welded joint is described, which consists in the explosive evaporation of a protrusion at the end of a hardware during the discharge of capacitor banks, the excitation and burning of an electric arc in the metal vapors of the parts to be welded, their convergence when the spring mechanism overcomes the pressure of metal vapors, the immersion of the hardware into the weld pool of the part with subsequent crystallization molten metal in the liquid phase. The spring mechanism was calibrated using a compression dynamometer. The flowing pulsed current was registered depending on the input energy of the discharge of capacitor banks. The main parameters of the capacitor welding mode are determined and the dependences on the input energy and preliminary static pressure are established. The indicator of mechanical tests was taken as a quality parameter - the pull-off force. The effect of metal vapor pressure, which counteracts the convergence of welded parts, is revealed. Dependences of opposing pressures to the convergence of welded parts are constructed.

Modelling and Experimental Study of Dissimilar Arc Stud Welding of AISI 304L to AISI 316L Stainless Steel

This paper has aimed to try and establish a successful weld joint between AISI 304L stainless steel as a stud and AISI 316L stainless steel as a plate by using an arc stud welding process. The effect of different current and time welding on the torque results was experimentally studied, by using three-level of each process parameters. The post-weld heat treatment (PWHT) was carried out on the optimum sample of torque, to study the effect of PWHT on mechanical properties (torque and hardness) and microstructure of the welding zone. In the present work, a3-D finite element model was developed by using ANSYS software version 18 to analyze the influence of time and current welding on the temperature distribution and residual stresses of the resultant welded joints. A transient thermal model was built to predict the temperature distribution whereas the residual stresses were determined by using a static structural model. The PWHT has been used to reduce the amount of residual stresses and enhance the mechanical properties of the welded joint. The micro-hardness based on the Vickers test and the microstructure of welded specimens of with and withoutPWHT have been investigated. The simulation results reveal that the generated temperature and the residual stress is strongly affected by the time and current welding. The mechanical test results indicated that the PWHT prompted an improvement in the hardness values.

Investigations on the microstructure of drawn arc stud welds on structural steels by quantitative metallography

The drawn arc stud welding is widely applied in steel construction, and its welding procedure can be qualified according to different standards by visual examinations and practical destructive tests of the resulting joint. An evaluation of the material properties is usually not requested particularly considering the locally limited weld region. Nevertheless, there is a need of knowledge regarding the complex press welding process metallurgy and resulting heterogeneous material properties in the welded zone, especially when welding on base materials with specified strength and toughness behavior that might be significantly diminished. In this study, the metallurgy of standardized large low alloyed Ø20 mm steel studs welded on plates of different generic structural steel grades is comprehensively analyzed by quantitative metallography. Structural steels with a moderate nominal yield strength of 355 MPa in non-alloyed normalized and micro-alloyed thermomechanically rolled delivery condition as well as a quenched and tempered structural steel with a high nominal yield strength of 690 MPa were investigated comparatively. Despite the different base plate compositions, very similar microstructures were found in the weld metal, whereas a typical quenching microstructure that strongly depends on the steel grade occurs in the heat-affected zone. A basic suitability of all steel grades regarding the DASW metallurgy was found.