Selection Of Welding Parameters Research Articles

Optimization and Analysis of Refill Friction Stir Spot Welding (RFSSW) Parameters of Dissimilar Aluminum Alloy Joints by FE and ANN Methods

The quality of the refill friction stir spot welding (RFSSW) process is heavily dependent on the selected welding parameters that influence the resultant joint characteristics. Thermomechanical phenomena integral to the process were investigated using finite element (FE) analysis on two dissimilar materials. This FE analysis was subsequently validated through controlled experiments to ensure reliability. An artificial neural network (ANN) was employed to create a neural model based on an experimental setup involving 120 different sets of welding parameters. The parameters adjusted in the experimental plan included pin penetration depth, rotational speed, retention time, and positioning relative to material hardness. To assess the neural model’s accuracy, outputs such as maximum temperature and normal stress at the end of the welding process were analyzed and validated by six data sets selected for their uniform distribution across the training domain.

Laser Welding of ARMOX 500T Steel.

The article describes the results of the study on laser welding of armor plates with a nominal thickness of 3.0 mm. The plates were made of Armox 500T steel characterized by a hardness of up to 540 HB, a minimum yield strength of 1250 MPa, an ultimate strength of up to 1750 MPa, and an elongation A5 minimum of 8%. The laser used for the welding tests was a solid state Yb:YAG laser. The influence of basic parameters such as laser output power, welding speed, and focal plane position on the weld geometry was determined during bead-on-plate welding tests. The optimal conditions for butt joint welding were determined, and the test joints were subjected to mechanical and impact tests, metallographic analysis, and hardness measurements. It has been shown that it is possible to laser weld Armox 500T armor plates, and at the same time it is possible to provide high quality butt joints, but this requires precise selection of welding parameters. A decrease in HAZ hardness of about 22-35% in relation to the hardness of the base material, ranging from 470 to 510 HV0.2, was found. The ultimate tensile strength of the test joints was approx. 20% lower than the Armox 500T steel. The bending tests revealed the low plasticity of the tested joints because the bending angle was just 25-35°. The results of Charpy V-notch test revealed that the impact toughness of the weld metal at -20 °C was approx. 30% lower than at room temperature.

Use of Artificial Neural Network to Evaluate and Forecast Selected Welding Parameters on Mild Steel Welded Joints Soldered by Tungsten Inert Gas

Use of Artificial Neural Network to Evaluate and Forecast Selected Welding Parameters on Mild Steel Welded Joints Soldered by Tungsten Inert Gas

Thermal effects of AISI 304-L stainless steel after laser irradiation

Laser Directed Energy Deposition (L-DED) is one of the Additive Manufacturing (AM) techniques that has emerged in recent years, and it is one of the disruptive technologies of the Industry 4.0. The selection of welding parameters of the L-DED system is critical for obtaining the desired results in metal deposition, however, due to its intrinsic nonlinear behavior in the process, the suitable choices need to be investigated. In this work it is presented an experimental setup to study the thermal effects on the metal substrate during the process of irradiation. With 40% and 60% of laser beam power, the irradiation results showed only a change in color, but no change in roughness or melting pool was formed. However, with 68% of laser power, a considerable increase of the substrate average temperature with values of more than 100°C at each adjacent track created was observed. The heat affected zone (HAZ) in this sample is expanded in both length and width as the temperature rises due the accumulation of heat during the irradiation process. It is concluded that the temperature of the substrate and other related process variables to be investigated must be controlled to achieve the desired bead formation.

Integrated Assessment of MIG Welding Parameters on Carbon Steel using RSM Optimisation

This study examined how parameter optimisation in MIG welding affects material properties, weld quality, flexural strength, and weld bead geometry using an experimental design. Structural testing reveals that weld pool imperfections, especially in welded joints, often lead to metal failure. Incorrect selection of welding parameters, material weldability, and metal forming contribute to defects and necessitate post-treatment. The study aims to minimize weld defects and maximize material strength in welded parts using a quadratic second-order regression model to predict optimal process parameters. The chosen JIS G3131 hot-rolled carbon steel material is commonly used in automotive parts, is cost-effective, and can be easily welded. The welding process is MIG buttweld according to AWS 1.1 standards. The tests match the RSM design's 3-by-3 orthogonal array. The process parameters are welding current, arc voltage, and welding speed. The responses are bead height, bead width, penetration, and flexural strength. NDT X-ray radiography detects flaws in weld pools. The welded connection's durability is determined with a three-point bending test. Experiments are conducted to find the best input parameters with 95% confidence. This study also uses an experimental design based on an orthogonal array and an analysis of variance (ANOVA). Contribution to factors and regression analysis. The predicted flexural strength was 903.1 MPa, with a 0.66% error compared to the experimental value of 897 MPa. Predicted values for weld penetration, bead width, and bead height are 3.01, 9.45, and 2.04. In the RT inspection test, the test sample with the optimum parameters had no defects in the welded joint. The optimal parameter values for the regression analysis of the RSM combination are 115, 20, and 18 for current, speed, and voltage. Confirmation tests for DT and NDT were performed to validate the optimal parameter settings. This research shows that optimizing process parameters for welded products improves weld geometry and flexural strength. This method is widely used and valuable in metal fabrication.

Optimization of TIG welding process parameters on 304 austenitic stainless steel sheet metal using fuzzy logic based Taguchi method

TIG welding can be used to produce excellent weld quality and precise welding operation for sheet metals. The aim of this study was to get the best welding parameters for enhancing ultimate tensile strength, bending strength and Rockwell hardness of the butt-weld joint. The experimental work was used, and the experiment was carried out on 2 mm thickness of 304 austenitic-stainless steel sheet metal using the L9 orthogonal array of the Taguchi design. Automated TIG welding fixture was developed to control the welding speed accurately. The selected welding parameters were welding speed, current, voltage and gas flow rate with their three levels. Based on the fuzzy logic based Taguchi method, the best optimal levels of parameters were found at the values of 110 A of current, 13.86 cm/min of speed, 17.5 V of voltage and 7.5 L/min of gas flow rate. The analysis results of ANOVA showed that gas flow rate and current were found as the significant factors, and the contributions of the gas flow rate, current, speed and error were 47.63%, 34.34%, 16.49% and 1.54%, respectively. According to the confirmation tests, the multi response performance index mean value of the confirmatory test of 0.6068 was found between the 95% confidence interval of 0.5028 and 0.7314, and the maximum ultimate tensile strength, bending strength and Rockwell hardness were obtained 614.8 MPa, 765.32 MPa and 95.3 HRB, respectively.

A Study on the Efficient Method of Underwater Welding Education for Commercial Diver

Although the requirements of underwater welding has been increasing in the marine field, limited studies have been conducted on the systematic approaches for underwater welding education. The present study was conducted to provide baseline data to understand the educational underwater welding process for commercial diving candidates. For this, optimal welding parameters for underwater were configured, experimental welding dives were conducted, and weld coupons were inspected and analyzed.</br>The results of this study can be summarized as follows respective weld passes. In the root pass, the insufficient weld deposit sizes owing to the fast weld speed were the main defects. In the second pass, non-paralleled beads and insufficient weld convexity were the main defects. In the third pass, incomplete deposit between the beads and the unplaned weld surface were the main defects. Finally, macro-etching test revealed incomplete penetration, slag inclusion, undersize of weld and unplaned weld profile.</br>The aforementioned weld defects must be reduced for beginner welder divers, selecting welding parameters such as suitable amperage, accurate work angle, and weld speed as the main variables.

Effect of Microchemistry Elements in Relation of Laser Welding Parameters on the Morphology 304 Stainless Steel Welds Using Response Surface Methodology

Small differences in the contents of surface active elements can change flow direction and thus heat transfer, even for different batches of a given alloy. This study aims to determine the effects of sulfur on weld bead morphology in the laser process. The paper presents the results related to the weld bead shape of two thin AISI 304 industrial stainless steel casts. One cast contains 80 ppm (0.008%) of sulfur, considered as a high sulfur content, and the other one contains 30 ppm (0.003%) sulfur, which can be considered low sulfur. The welds were executed using a CO2 laser. The effects of laser power (3.75, 3.67, 6 kW), welding speed (1.25, 2.40, 2.45, 3.6 m/min), focus point position (2, 7, 12 mm), and shield gas (Helium, mixed 40% helium + 60% argon and mixed 70% helium + 30% argon) with a flow rate of 10 L/min on the depth of the weld (D) and the aspect ratio (R = D/W) were investigated using RSM (response surface methodology). The experimental results show that the transfer of energy from the laser beam to the workpiece can be total in cases where the selected welding parameters prevent plasma formation. For the 304 HS cast, the focus point is the major factor in determining the depth of penetration, and its contribution is up to 52.35%. However, for 304 LS, the interaction between shield gas and focus point seems to play an important role, and the contribution of their interaction raises to 28% in relation to the laser depth of the weld. Moreover, the study shows that sulfur plays a surface-active role only in the case of partial penetration beads, so that a 56% partially penetrated weld supports the hypothesis of its surface-active role in the formation of the weld pool. However, a penetration of only 36% confirms the effects of a sulfur surface-active when the bead is fully penetrated.

Analysis of Voltage, Current Density, and Welding Speed of Flux Core Arc Welding on the Hardness and Micro-Structure of High Strength Low Alloy (ASTM A572)

This study was carried out to investigate the effect of Flux Core Arc Welding factors on the mechanical properties of High Strength Low Alloy (HSLA). These selected welding parameters were the voltage, current density and welding speed which determined the heat input. The mechanical properties were obtained by performing the hardness test. As for the microstructure changes were observed by metallography test. In the weld metal area, the highest hardness value of 177.8 HV was found in sample with low heat input, followed by high heat input samples of 167.03 HV. From the results, the hardness value is inversely proportional to the heat input. Furthermore, the metallography test gave a result that the hardness has a strong correlation with the ratio of ferrite and pearlite. The higher the hardness, the ratio of ferrite and pearlite was smaller.

Influence of Heat Input on Microstructure and Mechanical Properties of Laser Welding GH4169 Bolt Assembly—Numerical and Experimental Analysis

By conducting the numerical and experimental analysis, the influence of heat input on the microstructures and mechanical properties of laser welding GH4169 bolt assembly is systematically investigated. The weld formation, temperature field, and residual stress distribution during laser welding by using the finite element modeling are consistent with experimental results. The numerical simulation results show that the increase of heat input imparts lower residual stresses and higher temperature gradient. During the process of laser welding, the steepest temperature gradient and the peak residual stress arise in the fusion zone (FZ). In addition, the dissolution of γ″ and γ′ toward the fusion line increases in heat affected zone (HAZ), but only Laves phase is observed in FZ. With increasing heat input from 24 to 48 J mm−1, the ultimate tensile strength of welded joints decreases. Both the lowest microhardness values and tensile failure of GH4169 alloy laser welded joint are in FZ. Herein, it is that the relationship among the heat input, microstructures, and mechanical properties of GH4196 bolt assembly in laser welding is systematically established, which will be of guiding significance for the selection of welding parameters in aerospace.

Parameters optimization of tungsten inert gas welding process on 304L stainless steel using grey based Taguchi method

Tungsten inert gas can be used to weld stainless steel due to its offering sound weld, narrow fusion zone, precise control weld’s shape and over penetration, spatter free, slagless, stable arc and low electrode wear. The goal of this study was to offer the best process parameters for improving the mechanical characteristics of the weld joint. The experimental analysis approach was applied in this work, and the experiment was carried out on 304L stainless steel using L16. The selected welding parameters were welding travel speed, current of welding, gas flow rate, arc length, and root gap. Rockwell hardness, tensile strength, and bending strength tests were the examined mechanical properties on the weld joint. Based on the grey based Taguchi method, the optimal level-settings of welding travel speed, current of welding, flow rate of gas, arc length, and root gap were obtained 2.7 mm s−1, 160 A, 14 l min−1, 3 mm, and 1 mm, respectively. The analysis result of ANOVA showed that the current has the greatest impact and it was followed by travel speed and root gap on weld joint quality with percentage contribution of 80.77%, 10.86%, and 5.98%, respectively. According to confirmation results, the average grey relational grade of 0.863 which was found between the confidence interval of 0.800 to 1.082 for the 95% confidence level, and the maximum Rockwell hardness, tensile strength and bending strength were obtained 101.38 HRB, 1425.8 MPa and 1648.6 MPa, respectively.

IMPROVEMENT OF THE MECHANICAL PROPERTIES OF MOBILE PLATFORM STAINLESS CONSTRUCTION ELEMENTS

Stainless steel could be treated as the main material used to construct various means of transport, including mobile platforms and tank trucks. An austenitic steel known as 316L steel (1.4401) has high resistance to atmospheric corrosion, natural waters, water vapor, alkaline solutions, and acids, even at elevated temperatures. This steel is weldable, although it is also prone to various types of welding cracks. Many factors influence the quality and mechanical properties of a joint. The most significant of these is the appropriate selection of welding parameters, which should be determined precisely and separately for each type of sheet, depending on its thickness and geometric features. The aim of the present article is to study the influence of main TIG (Tungsten inert gas) welding parameters on the creation of proper joints used in the construction of mobile truck platforms or tank trucks. The proper selection of parameters enables the production of welds with good functional properties. A novelty of this article is the proposal to weld each layer of a thick joint with different parameters, which has an important influence on the mechanical properties of the joint. It is expected that the new material and technological solution will yield a joint with good corrosion resistance and increased mechanical properties. This is important in the responsible construction of means of transport, using the example of mobile platforms and tank trucks. Different tests verifying the properties of joints, including non-destructive testing, tensile strength tests, and fatigue tests, as well as a hardness probe, were applied.

Hardox 450 Weld in Microstructural and Mechanical Approaches after Welding at Micro-Jet Cooling.

The demand for high-strength steel welds, as observed in civil and transport engineering, is related to a mass reduction in vehicles. Container-type trucks are examples of this kind of transport means because their boxes are able to be produced using Hardox grade steels. Therefore, this study reflects on the properties of welds in the MAG welding of Hardox 450, obtained through an innovative micro-jet cooling process with helium. This joining technology aims to reduce the formation of defects and to obtain a joint with very good assumed mechanical properties. Structural components of grade steel require welds with acceptable mechanical parameters with respect to operational loading conditions. That is, this study focuses on selecting welding parameters for the Hardox 450 steel and determining the weld quality with respect to microstructural observations and mechanical tests, such as the Charpy, tensile and fatigue tests. Weld fracturing under increasing monotonic force was examined and was strongly related to both stress components, i.e., axial and shear. The joint response under fatigue was expressed through differences in the fracture zones, i.e., at a stress value lower than the proportional limit, and weld degradation occurred in the shear and axial stress components. The data indicate that the hourglass specimen, with the weld in the centre zone of the measurement section, can be directly used to determine a weld response under cyclic loading. The impact test results showed attractive behaviour in the tested joint, as represented by 47 J at −20 °C. The recommended MAG welding parameters for Hardox 450 steel are low-oxygen when using an Ar + 18% CO2 shielding mixture. The collected results can be directly used as a guide to weld thin-walled structures (6 mm) made of Hardox grade steel, while the data from mechanical tests can support the modelling, designing and manufacturing of components made from this kind of steel grade.

Study of the compression properties of welded seams formed using hot wedge, hot air, ultrasonic, and high-frequency welding techniques

The compression properties of welded seams depending on welding parameters using the hot wedge and hot air welding technique, ultrasonic welding technique, and high-frequency welding technique were studied. The compression properties, expressed by parameters such as compressional energy WC, compressional resilience RC, linearity LC, and compressibility C, are important information about the welded seam quality in terms of touch, voluminosity, stiffness, and flexibility of the welded seam. KES-FB and FAST measurement systems were used to test the compression properties of the welded seams. Based on the analysis of the results obtained, the influence of the welding parameters on the compression properties of the welded seam was determined. The results of the investigation showed that improperly selected welding parameters, such as the supply or introduction of too much heat into the material to be welded or too long exposure of the material in the weld zone to heat, result in welded seams with expressive extrusion edges, which affects the quality of the welded seams. These welded seams have very low values of compressional resilience RC and very high values of compressional energy WC and compressibility C.

Investigation of the Effect of Solid Wire and Flux Combinations Used in Submerged Arc Welding of the LPG Cylinders on Mechanical Properties

Liquefied petroleum gas (LPG) cylinder is a type of pressure vessel that used to store and transport liquefied gases. In this study, S460MC steel with a thickness of 1.50 mm and submerged arc welding method were used in the manufacturing of LPG cylinders. Selection of the welding consumables (wire, flux) and optimization of the welding parameters (current, voltage, travel speed) are the primary focus of the study. Selected welding parameters have been verified as a result of visual and radiographic (X-ray) tests and macroscopic examinations. In order to analyze the effects of welding consumables on mechanical properties, test specimens were prepared, then tensile and hardness tests were performed and it was observed that molybdenum element increased the mechanical strength. In order to fulfill the requirements of the LPG cylinder production standard, bursting & volumetric expansion tests and pressure fatigue tests were performed and the requirements were met.

Optimization of Mig Welding Process Parameters with Grey Relational Analysis for Al 6061 Alloy

: Aluminum alloy Al 6061 alloy has good combination of mechanical properties. It has wide applications in aerospace and marine industries. However welded part of alloy differs in properties which intern depends on welding input parameters. The proper selection of welding parameters plays a important significance on improvement in weldbead geometry. This present research focused on study of welding parameters of MIG welding of alloy Al 6061 by Taguchi’s GR analysis using L32 orthogonal array. Angle of torch, Wire feedrate, Standoff distance, Welding speed and Welding current are different parameters considered for analysis. AN0VA method used to obtain the importance of each parameter on weldbead. From ANOVA it was found that welding current plays significant role and followed by wire feedrate, welding speed, angle of torch and least influenced by standoff distance.

Welding parameters optimization during plunging and dwelling phase of FSW 2219 aluminum alloy thick plate

The influence of welding parameters on temperature distribution during plunging and dwelling phase of friction stir welding (FSW) 2219 aluminum alloy thick plate has not been studied. Improper selection of welding parameters will result in uneven temperature distribution along with the thickness of the weldment, leading to welding defects and ultimately affecting the mechanical properties of the weldment. To achieve the prediction of temperature distribution and the optimization of welding parameters, a simulation process model of FSW 18-mm-thick 2219 aluminum alloy is established based on DEFORM. The validity of the simulation is verified by experiments. With the minimum temperature difference in the core area of the weldment as the target value and weldable temperature range of 2219 aluminum alloy as the constraint conditions, orthogonal experiments are conducted considering the rotational speed, the press amount, the tool tilt angle, the plunging traverse speed and the dwelling time. The results of variance analysis show that the rotational speed and the dwelling time are significant factors affecting the temperature field during the plunging and dwelling phase. Through single factor simulation, the welding parameters during the plunging and dwelling phase are optimized. This study guides the selection of welding parameters of the FSW 2219 aluminum alloy thick plate.

Development of Mathematical Model for Percentage of Elongation of TIG Welded Duplex Stainless Steel

Quality strongly depends on good mechanical properties of any manufacturing material. Similarly, quality of Tungsten Inert Gas (TIG) welding of Duplex Stainless Steel (DSS) depends on good mechanical properties like percentage of elongation, ultimate tensile strength etc. Better Percentage of Elongation (PE) is produced using proper welding parameters and their values at the time of TIG welding. In this study, TIG welding has been done on ASTM/UNS 2205 duplex stainless steel materials. A new mathematical model is developed using non-linear regression analysis for the prediction of percentage of elongation. The variables used in the prediction models are selected welding parameters like welding current, gas flow rate and speed of welding. A residual plot for PE has been developed to validate the mathematical model. Calculation of percentage deviation for PE has been made. Comparison of measured and predicted PE value has been done by graphical representation. The relationship between percentage of elongation and the welding parameters has been illustrated graphically by surface plots and contour plots as well. Combined effects of any pair of input parameters on PE are represented graphically with the help of three-dimensional surface plots. According to this analysis, the models provide good PE with the data used in this study.

Friction stir welding of two major pin contours of AA2024 and AA6061

The research work deals with to join two dissimilar aluminum alloys by solid state welding process compared to fusion welding processes and compared with fusion welding process, fusion welds tend to produce more defects while joining dissimilar materials. The major problem of the two dissimilar metals involve in welding process have different mechanical properties and microstructures which in turn may affect welding parameters like weld current, hold time, weld force etc. In order to overcome these issues, Friction Stir Welding (FSW) can be used to get rid of defects since it uses a non-consumable tool and also produces defect free welds compared to other welding processes. This thesis work aims to joining an aluminum alloy of 2024 and aluminum alloy of 6061. The plates are joined by means of octagon probe tool made of high carbon high chromium steel (D2 tool steel). Other issues while welding dissimilar aluminum alloys are phase transformation change and selection of welding parameters (rotational speed, transvers speed, pin diameter, shoulder diameter, D/d ratio and etc.) From conducted trail experiment aluminum alloy of 2024 and aluminum alloy of 6061 by using octagon probe tool made by HC-HCR tool it was observed that a lower welding speed 500 rpm at starting stage lack of filling took place and after thermo-mechanical heating took place that produce better weld while compared to weld at higher speeds (710 rpm, and 1000 rpm) with same transvers speed of 20 mm/min.

Brief Survey of the Microstructural, Mechanical and Corrosion Properties of Duplex Stainless Steels SMAW Weldments.

Duplex stainless steels (DSSs) structures, especially the American Iron and Steel Institute (AISI)type 2205 and 2507 have greatly attracted the attention of many researchers, engineers, manufacturers as well as the end-users of the productsbecause of its superior engineering properties like strength, good toughness, particular resistance to corrosive environments and to stress corrosion cracking (SCC). Due to its worldwide progressive growth, demand and utilization, this novel steel (DSS) is rising very fast, especially in marine, power plants, chemical process, mining, petrochemical, oil and gas, pharmaceutical and many other related engineering applications. Generally, the joining of DSSs alloys is a big problem due to its susceptibility to sensitization caused by the precipitation of additional phases when heated above 600°C. Conversely, improper selection of welding parameters, imbalance ratio of austenite/ferrite phases can lead to corrosion susceptibility, solidification cracking and susceptibility to plastic deformation. Shielded metal arc welding (SMAW) technique with recommended consumables (E2209 and E2594 or E2595) is used in the fabrication of the multiphase steels with the aim of obtaining the optimum weldment with the desired input welding criteria, optimum mechanical properties with minimum defects from the microstructural perspective and excellent corrosion behaviours. This review is therefore geared towards accentuating the influence of arc welding processes, and SMAW in particular on the microstructure, mechanical and corrosion properties of DSSs weldment.