GMAW Welding Research Articles

The Influence of Oscillation Parameters on the Formation of Overhead Welding Seams in the Narrow-Gap GMAW Process

Thick-walled X80 pipelines for oil and gas transportation are difficult to relocate due to their large size. In the process of narrow-gap overhead welding, welding defects, such as bulges and lack of sidewall fusion, can appear easily. To avoid these defects and to improve the welding quality of thick-walled pipelines, the GMAW welding method is adopted in this paper. The formation characteristics of the weld and the influence of arc oscillation parameters, such as the oscillation width and sidewall dwell time, on the formation process of narrow-gap overhead welding seams are studied. In this research, it was found that, in the NG-GMAW overhead welding position, there was a downward trend in the middle of the formed surface of the weld pool. Defects, such as finger-shaped penetrations and lack of sidewall fusion, were prone to occur due to gravity. The increased oscillation width was beneficial for reducing the protrusion in the middle of the weld seam, but an excessive oscillation width can easily cause undercut defects. The sidewall dwell time has little effect on the protrusion in the middle of the weld seam, but it can increase sidewall penetration, thereby avoiding the occurrence of incomplete sidewall penetration.

PENGARUH VARIASI METAL TRANSFER TERHADAP KARAKTERISTIK SAMBUNGAN LAS PADA PROSES PENGELASAN GMAW DENGAN PELINDUNG GAS ARGON

This study aims to determine the variation of metal transfer on tensile strength, impact, hardness distribution, macrostructure, microstructure and chemical composition of low carbon steel metal by GMAW welding method. The material used in this study was AISI 1018 low carbon steel. The material was welded using the GMAW method. Variation of globular arc, spray arc and short arc welding. The tests carried out included tensile testing, impact testing, hardness testing, macro-structural observations, micro-structural observations and chemical composition. The test phase to determine tensile strength refers to ASTM E8/E8M-09 with specimen dimensions of 100 mm long, 10 mm wide and 5 mm thick, while for impact testing refers to ASTM E23-07a with dimensions of 55 mm long, 10 mm wide and 10 mm thick. 10 mm with a notch depth of 5 mm and photographic observations of macro, micro and chemical composition. The test results show that the maximum tensile strength with the globular arc welding method is 526.3 MPa and the yield stress is 377.3 MPa, which is greater than that of the low carbon steel parent metal, which is 454 MPa. The impact toughness value of the globular arc welding method is 3.58 J/mm2. Results The microstructure of the weld metal undergoes structural changes in all welding methods. The test results for the chemical composition of the Fe content in low carbon steel materials by welding were 98.78% to 97.76%.

Wire electrode of 5754 aluminum modified by PVD-thin film depositions

Manufacturers of welding wire electrodes for GMAW welding adapt the alloy compositions of welding wire electrodes in order to adjust the weld pool behavior and the properties of the weld. Additively manufactured components in various sizes and with complex structures and multi-axial stress states place diverse demands on the material. The filler wire can significantly influence the material properties. The approach shown here describes the possibility of coating welding wire electrodes by physical vapor deposition, which enables flexible adjustment of the welding material composition. The element content in the weld metal can be adjusted within certain limits via the coating thickness. In the arc, applied thin-film coatings with coating thicknesses < 1 µm pass into the molten phase together with the substrate wire electrode according to ISO 18273—S Al 5754 (AlMg3). Microalloying elements such as TiB2 or Ti added to the weld pool in this way change the composition and thus influence the microstructure in the weld metal. This results in a grain refinement of up to 46%, which in turn has a positive effect on hot cracking susceptibility. PVD-coated welding electrodes also show changes in arc characteristics. With increasing TiB2 layer thickness, the arc length decreases by up to 44%, while the arc current increases. The fusion penetration behavior changes from a narrow finger-shaped to a round fusion penetration.

GMAW welding procedure expert system based on machine learning

In order to simplify the robot preparation before welding and improve the automation of the whole welding process, an intelligent expert system for Gas Metal Arc Welding is designed in this paper. In the system, the user inputs the initial welding information and the output interface displays suitable welding procedure parameter schemes. The user can choose the schemes according to the actual requirements or directly generate the welding procedure specification required by the enterprise format for direct use. In addition, the system also combines the database technology and XGBoost algorithm in the field of machine learning, migrates the model trained on the data set to predict the welding raw data, accumulates more data for daily use to optimize the model, which makes the whole system more systematic and intelligent, and achieves the goal of more accurate use.

Heat input effect in a multipass and double-wire GMAW welding of a thick structural steel for industrial applications

Heat input effect in a multipass and double-wire GMAW welding of a thick structural steel for industrial applications

ANALISIS SAMBUNGAN LAS GMAW BAJA ASTM A36 YANG TERPAPAR PANAS TINGGI DAN PENDINGINAN CEPAT

Fires in steel construction, especially in welding joints, cause damage, changes in crystal structure, and mechanical properties of the material. Another effect of the fires, the material undergoes rapid cooling due to extinguishing using water. This research aims to simulate fires on ASTM A36 steel material to analyze the impact of fires. The method of this research is to perform GMAW welding on A36 steel material with heat treatment at 400 °C unti 700 °C and rapid cooling using water. The results of the research are the mechanical properties of the material in the form of crystal structure, hardness level and ultimate tensile strength. The crystal structure of ferrite and pearlite was observed, there was a change in structure, namely coarse ferrite, fine ferrite, and a mixture of bainite martensite. The highest hardness values of coupons temperature is 550 °C until 700 °C, comparison coupons, and coupons temperature at 400 °C-550 °C, which value 169,3 HV, 166.3 HV, and 141,3 HV in the weld zone. Tensile test fractures on the base metal with the ultimate tensile strength coupon with temperature 550 until 700 °C of 481,75 N/mm², the comparison coupon of 478,5 N/mm², and the temperature coupon of 400 until 550 °C which is 456 N/mm². The material is ductile.

Influence of parameters on the microstructure of a duplex stainless steel joint welded by a GMAW welding process

Duplex stainless steels (DSSs) are widely used in industry for their desirable properties. Any fusion welding technique modifies the microstructure and, consequently, the properties of the material. This paper presents a parametric study of the variables that determine the energy contribution (current, voltage and welding speed) and the structural modifications produced during gas metal arc welding. The analysis comprises metallographic study, phase balance, dimensioning of the weld beads and tensile and hardness tests. The influence of the variables studied on the thermal cycles obtained (temperatures reached and cooling rate) was determined by using a finite element model. The results showed that, in addition to the indicated parameters, the parameter power transfer per volume (W/m3) and the geometry in the bead must be controlled due to their influence on the heat flow distribution and phase balance.

Analysis of the Toughness of the Vertical Position GMAW Welding on Steel ST 42 with Electrode Spiral Movement Pattern

This study aims to determine the toughness value of vertical position GMAW welding on ST 42 steel with a spiral electrode motion pattern. This study consisted of ST 42 steel, cut to the standard ASTM E23 specimen as many as 20 samples. The toughness value of the GMAW welding results in a vertical position, describes the strength and toughness of the material in making ST 42 steel joints. The results of the ST 42 steel impact test with spiral; the average value of impact toughness was 135.375 Joule with an impact value of 0.2461 (J/mm²), while without treatment the average impact toughness was 183.975 Joule with an impact value of 0.3345 (J/mm²). Thus, it can be concluded that the impact toughness of ST 42 steel with a spiral electrode movement pattern is smaller than the impact toughness without welding joint treatment means that the toughness of ST 42 steel without a connection is stronger than using a welded joint with a spiral electrode motion pattern.

Comparative Analysis of GTAW, GMAW, and FCAW Welding Results on A36 Steel Against Tensile Test and Macrostructure

Offshore building construction is inseparable from the fabrication process. Fabrication process that has an important role in terms of engineering, material repair and welding process. In offshore building construction, a precise welding method is needed on A36, where A36 steel is one of the main materials in the fabrication process of offshore buildings. In this study a comparison of welding results of GTAW, GMAW, and FCAW on A36 steel against Tensile Test and Macrostructure Test. The results of this research show that the best tensile test results are the GTAW welding method with an average value of ultimate strength of 462,168 MPa. Macrostructure testing which has the widest HAZ width is the GTAW welding method of 18,71 mm.

Investigation of Process Parameters on Strength of Welding Joint in GMAW

The strength value most desired in any welding process is an excellent Ultimate Tensile Strength (UTS) of the weld, compared with the parent metal. Process parameters applied during the welding process ought to be subjected to continuous scrutiny and assessment because of the ever increasing demand for structural and industrial materials with weld joints possessing higher strength values. This study is intended to investigate the inadequacies of existing GMAW welding process parameters utilized by the investigated industrial firm in its signature welding protocol, by suggesting alternative, uniquely crafted, and improved process parameters to replace its existing signature welding protocol, thereby improving the weld results by attaining higher UTS. These suggested process parameters were thereafter subjected to reported literature, following which optimization was achieved by employing the Taguchi Method. Then in future work we will study the strength on universal testing machine and calculating the results.

Heterogeneous Measurement System for Data Mining Robotic GMAW Weld Quality

During robotic welding, several streams of heterogeneous data can be collected. To gain a systemic understanding of the welding process, these data streams have to be combined precisely and accurately, especially if our goal is to develop online weld quality assessments. Establishing correspondence among temporal and spatially based data is a nontrivial effort. This article presents a data collection system using a novel methodology for establishing correspondence across multiple data sources of robotic gas metal arc welding for objective quality assessment. First, correspondence between the weld process data and the resulting weld required time synchronization and spatial alignment. Second, an objective weld quality extraction technique that assigns quantitative measures at a resolution of 1 mm of linear weld travel was developed to evaluate weld quality. Specifically, in addition to developing a method for objective weld profile assessment, we developed an objective analysis of radiographic data for the occurrence of subsurface porosity to assess defects and demonstrate how to objectively quantify the occurrence of surface porosity. While some aspects of this paper have been addressed individually and separately by other research, this paper presents an integrated approach to these operations for a wide variety of weld data types and develops objective weld quality metrics that can be used for machine learning of weld quality for robotic welding.

An artificial neural network approach for parametric study on welding defect classification

In this paper, a welding defect prediction model has been developed and investigated through training an artificial neural network (ANN) based model. The input data were three welding process measurements (welding current, travel speed, and protective gas flow). The output data were non-destructive test results of respective weldments on four defect types (underfill, lack of penetration,incomplete fusion, and porosity) to ensure the consistency of the welding following the designed parameters; all data were obtained from 289 specimens produced by an automated GMAW welding manufacturing system. The 2-stages model comprises 13 inputs, hidden layers with 80–100 neurons and 4 outputs. The outputs were used to evaluate the classification accuracy in the confusion matrix for the prediction of weld quality. A further 73 specimens were used to test the accuracy of the trained ANN model. The model achieved 85% accuracy.

Study on intermediate temperature brittleness mechanism of Inconel 625 deposited metal

Inconel 625 surfacing specimens were prepared on the surface of carbon steel by GMAW welding. The microstructure was studied by OM, SEM, XRD and TEM, and the tensile properties were analyzed at different temperatures. The results show that the main precipitates are Laves phase and MC carbides. The tensile properties are strongly dependent on temperature, and there is an obvious intermediate temperature brittleness behavior. With the increase of temperature, the tensile strength (below 700 °C) and yield strength (below 760 °C) decrease slightly, however decrease significantly after the temperature exceeds 700 °C. However, the tensile plasticity decreased significantly, and reached the lowest value at 700 °C. The TEM observation shows that the main deformation mechanism of dislocation is cutting precipitates at 20 °C–700 °C. Some continuous stacking faults and K–W locks can be observed at 700 °C. At 760 °C, the dislocation loops appear in the microstructure, that is, the dislocation bypass mechanism starts. At 800 °C - 900 °C, the dislocation networks were observed in the microstructure, and the bypass mechanism was dominant.

Karakterizacija mag pulsnog zavarivanja uključujući snimanje dinamičkih karakteristika i proračun unosa toplote

In GMAW welding, there are several types of metal transfer that are primarily determined by the primary welding parameters. Different metal transfers in an electric arc are characteristic of different applications. In this paper, a detailed characterization of the pulse transfer of metals in an electric arc is performed, including the characterization of parameters and criteria for their selection on the used power source for welding Welbee. For a given Welbee device, the choice of parameters in steel welding is shown, as well as the synergy function that is characteristic of these devices. Welding was performed on structural steels, with previously adopted parameters, accompanied by recording the dynamic characteristics of current and voltage with an oscilloscope. Based on the available literature sources, the existing models for heat input calculation in GMAW pulse welding were analysed in detail. Heat input calculation for welded steel sheets was performed by using one of them, with current and voltage profiles recorded with an oscilloscope. After the experiment, the obtained results were elaborated, and general comments were given regarding influence of parameters on the quality of welded joints.

Gas metal arc welding of metal-polymer-metal sheets

Metal-polymer-metal (MPM) sheets are sandwich panels used for housings of large industrial electric motors and generators, vehicle body panels, flooring, various bulkheads, wheel arching, engine and gearbox shielding, etc. Their main advantage over classic steel panels in form of plates is their acoustic dampening properties. Joining of such plating is challenging because the polymer interlayer evaporates and the resulting fumes may cause the plates to deform. In this paper, GMAW welding was used to join metal-polymer-metal sheets, with a square butt joint, single V butt joint combined in one sheet, as well as welding in one pass per side and in multiple bead segments. C1 (CO2) and M21 (Ar + 18 % CO2) shielding gases were used. Tensile, bending and hardness tests were performed, macro and microstructures were tested and the evaporation, melting and cross-linking distances were recorded. It was shown that contrary to the recent tendency of using M21 shielding gas for GMAW welding, C1 proved to offer superior tensile and bending properties of the joint. From the point of view of simplicity and productivity, a square butt joint proved to be optimal.

Bead Geometry Prediction in Pulsed GMAW Welding: A Comparative Study on the Performance of Artificial Neural Network and Regression Models

Weld bead geometry is a critical factor for determining the quality of welded joints, for this the welding process input parameters play a key role. In this study, the relationships between welding process variables and the size of the weld bead produced by pulsed GMAW process were investigated by a neural network trained with Bayesian-Regulation Back Propagation algorithm and a second degree regression models. A series of experiments were carried out by applying a Box-Behnken design of experiment. The results showed that both models can predict well the bead geometry. However, the neural network model had a slightly better performance than the second-order regression model. Both models can be used for further analyses and using them may surmount or reduce the need of experimental procedures especially in thermal analysis validations of welding finite element modelling.

Effect of Temperature Variation of Static Thermal Tensioning on Angular Distortion and Sensitization behavior of GMAW Welded SUS 304 Stainless Steel Plate

Due to its rust resistance properties, the use of stainless steels, especially SUS304 for industrial equipment is increasing. The manufacturing process that is often used is GMAW welding. One of the disadvantages of SUS304 is the occurrence of distortion and sensitization when welded. In this study, the effect of temperature variations of Static Thermal Tensioning on angle distortion and microstructure behavior due to GMAW welding of SUS 304 T-joint plates was studied. Heating by electric heater is given to both parts of the base metal plate SUS 304 5mm thick with temperature variations of 200 oC, 250 oC and 300 oC. Cooling water with a temperature of 24 oC is provided on the back side of the welded track. Welding using filler ER 304 with a diameter of 0.8 mm with welding parameters such as welding current, voltage, gas flow and travel speed controlled at 75 A, 22 V, 10 l/min and 8 mm/s, respectively. Angular distortion of welding results for each treatment temperature variation was measured using a bevel protractor, and perform metallographic test to knowing the microstructural behavior. The results of the measurement of the average angular distortion of three repetitions show that at a temperature of 250 C static thermal tensioning produces the smallest angular distortion of 3ᵒ70', compared to other temperature variations which produce angular distortion 4o45’ at 200 oC and 3o86' at temperature 300 oC. The findings of the largest Cr (carbide) deposits due to sensitization were found at a temperature of 300 oC at 16,49% and the lowest at a temperature of 200 oC at 7,05%

Comparative Analysis of FCAW, and GMAW Welding With Heat Input Variations on A36 Steel Against Vickers Hardness Test and Macrostructure

In offshore building construction, a precise welding method is needed on A36 steel, where A36 steel is one of the main materials in the fabrication process of offshore buildings. In this study a comparison of the results of the welding GMAW and FCAW with variations of the heat input on the A36 steel to the Hardness test, and the macrostructure test and the selection of the most appropriate method based on the results of the mechanical test analysis. The heat input variations used are GMAW 1.50 kJ / mm and 2.03 kJ / mm while for FCAW 1.90 kJ / mm and 2.30 kJ / mm. The results of this study are the best hardness test results are the FCAW welding method with a heat input of 2.30 kJ / mm with an average ultimate strength of 149.06 HVN, in the macro test the results show that the greater the heat input, the wider the HAZ area, this is shown by welding FCAW heat input 2.30 kj / mm which has a HAZ width area of 20 mm.

Mechanisms of an innovative hybrid arc welding process in enhancing joint penetration and weld property control through resistive and induction heat

Low costs (material, energy and time), high joint properties are the eternal pursuit of modern welding. In this paper, mechanisms of an innovative high frequency electric cooperated arc welding (HFAW) in enhancing welding productivity (joint penetration) and weld property control were comprehensively investigated. The process properties and weld mechanisms of this method were systematically compared with that of the traditional GMAW welding under typical process parameters. The results showed that 4.8 mm joint with an large aspect ratio of 4 was achieved by single pass HFAW at a high welding speed (15 mm/s) and a low welding heat input (reduced 1/3 than the traditional GMAW). The research on weld property control shows that the microstructure of weld zone and heat affected zone (HAZ) in the HFAW joint was much smaller than that in the GMAW joint under optimal parameters. The width of each zone in the HAZ, thermal cycle parameters such as elevated temperature holding time and cooling rate can be regulated independently by the high frequency electric heat input ratio. Such regulation is of great significance for high strength steel welding, which needs to control the welding thermal cycle process accurately. Combined with three-dimensional solid reconstruction of liquid filler metal, the mechanism of the HFAW in enhancing joint penetration was demonstrated. An interesting “self-tracking heating” of the high frequency current was found. The cutting-edge of the liquid metal was violently heated and more than half of the weld in thickness direction was achieved by a novel ultra-speed “interfacial tension driving penetrating” weld forming mechanism, which promises the HFAW high welding speed and large aspect ratio on the premise of satisfactory welding quality.

Frame Head Production Process In Category 3 Frame Chassis At Pt. Prime Dual Core

The frame is the main component of the chassis that functions to withstand shock, pressure and vibration when operating on the road. The chassis frame is made of SS400 material which has a good level of strength to withstand static loads, the Frame Chassis formation process uses a cold working process. This writing aims to determine the production process of the Frame Head on the Frame Chassis category 3 as well as knowing the machines used in the Frame Head production process and knowing the total tonnage required for the 400 ton Stamping machine in the blanking and piercing process on the Crossmember 0101 part, from observations that have been made. it was done that to carry out the Frame Head production process on Frame Chassis category 3, through the process of forming material or forming with the blanking, piercing, and bending methods using a 300 ton to 500 ton stamping machine, then continued with the unification process using a GMAW welding machine ( Gas Metal Arc Welding), then continued with the painting process using powder coating with the dipping method for 2 minutes, and in the Crossmember 0101 forming part process using a 400 ton Stamping machine, the total tonnage of the blanking and piercing cutting force was obtained on the Crossmember 0101 part (added with backup/strippin style g force) is 470.069 Tons.