Metal Arc Welding Research Articles

Comparison of Low Cryogenic Impact Toughness and Microstructure of GMAW (Gas Metal Arc Welding) and GTAW (Gas Tungsten Arc Welding) Weld Zone in 304L Stainless Steel for Liquid Hydrogen Tank

To combat global climate change caused by CO2 emissions, achieving net-zero emissions through sustainable energy solutions is a global priority. Among alternative energy carriers, hydrogen is a promising renewable energy source due to its efficiency in production, transportation, and storage. Liquefied hydrogen (LH2) transportation is gaining attention as it significantly reduces volume and enhances efficiency. However, LH2 storage containers require specialized materials with excellent cryogenic mechanical properties and hydrogen embrittlement resistance. Austenitic stainless steel (ASS), specifically 304L, is a strong candidate due to its superior mechanical properties at cryogenic temperatures and resistance to hydrogen embrittlement. In fabrication of ASS, Gas Tungsten Arc Welding (GTAW) and Gas Metal Arc Welding (GMAW) are commonly used. This study investigates the micro structural and mechanical properties in ASS 304L welds using 308L filler metal under these welding processes. Weld bead morphology, microstructural characteristics, and cryogenic mechanical properties were analyzed using Optical Microscopy (OM), Scanning Electron Microscopy (SEM), and Electron Probe Micro Analysis (EPMA). Additionally, tensile, hardness, and Charpy impact tests at room and cryogenic temperatures were conducted. The results provide insights into the impact of heat input on δ-ferrite distribution, grain structure, and mechanical properties, contributing to the optimization of welding processes for LH2 storage applications.

Analysis of mechanical properties, microstructure, and distortion of Al6061-T6 alloys plate using GTA and GMA welding process

This study compares the effect of filler metal and welding current of gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW) on Aluminium alloy Al6061-T6. Three different filler metals, ER4043, ER4047, and ER5356, were used with the GTAW welding process. The welded joints were created at three different welding currents (120, 130, and 140 A) by the GMAW with filler metals ER5356. Optical and scanning electron microscopy (SEM) is used to analyze the surface fracture of impact test welding joints. The results showed that the GMAW process had the most optimum Ultimate Tensile Strenght (UTS) compared to the GTAW welding joint, especially for welding current 130 A. The impact strength of ER4047 filler metal with the GTAW process is higher than other joints (61 J/cm2). Optimum conditions were obtained by the GMAW welding process using a welding current of 130 A with maximum tensile strength and impact strength of 350 MPa and 53 J/cm2, respectively. SEM analysis showed obtained Mg2Si a globular morphology in ER4047 and ER5356 filler metals, and the dimples fracture is indicated at all joints with the GMAW and GTAW processes. Furthermore, increasing welding current by the GMAW process causes higher angular distortion, reduced vickers hardness but does not significantly affect the weld bead. Overall, the GMAW produces better physical and mechanical properties of weld joint compared to GTAW for all types of filler metals but results in greater angular distortion

Study on the Load-bearing Capacity of X80 Submerged Arc Welded Joints Based on Finite Element Model

As the petroleum industry continues to expand rapidly, X80 pipeline steel has become a key material in oil and gas transportation due to its strength and durability. However, welding joints, a critical part of these pipelines, sometimes lack sufficient load-bearing capacity, leading to structural failures. Ensuring the mechanical integrity of these joints is essential for the safe and efficient operation of pipelines. This study employs ABAQUS finite element analysis to assess the performance of welded joints created using submerged arc welding (SAW) and gas metal arc welding (GMAW). By developing 3D models, the study simulates tensile testing, revealing that as displacement increases, the tensile force rises, causing plastic deformation. Necking occurs near the heat-affected zone in the base metal, eventually leading to fracture.Furthermore, internal pressure simulations show that as pressure builds, the highest stress concentration appears on the inner wall of the welded joints, emphasizing the importance of weld strength in high-pressure environments. By visually demonstrating the mechanical behavior of different welding techniques, this study provides valuable insights for improving welding processes in X80 pipeline steel. The findings serve as a theoretical foundation for optimizing pipeline construction and ensuring long-term structural safety in real-world applications.

Research Status and Prospects of MIG and Hybrid Welding of Titanium and Titanium Alloys

AbstractGas metal arc welding (MIG welding), as a significant welding method, has continuously evolved and improved alongside the expanding application of titanium alloy materials. This paper reviews the latest research progress in MIG welding and its hybrid welding technologies for titanium and its alloys. It delves into the advantages of MIG welding derivative technologies such as pulsed MIG welding, PMC MIG welding, CMT, and CMT+P, as well as hybrid welding technologies like Hot‐wire TIG, LW‐MIG, and PAW‐MIG, in enhancing welding efficiency, improving weld quality, and addressing the limitations of traditional welding. The characteristics of each technology are summarized and compared. Furthermore, it looks forward to the future development trends of welding technologies, including process optimization, environmental protection, automation and intelligence, and the development of new welding materials and high‐efficiency welding power sources, providing insights for the advancement of MIG welding and its hybrid welding technologies for titanium and its alloys.

Advancements and Challenges in Wire Arc Additive Manufacturing – A Review

Wire arc additive manufacturing (WAAM) is a groundbreaking advancement in 3D metal printing, enabling efficient and cost-effective production of large, complex components using gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW). Suitable for metals like stainless steel, aluminium, and titanium alloys, WAAM involves layer-by-layer deposition of molten metal using an electric arc to melt wire feedstock. Despite its benefits, WAAM faces challenges with thermal cycles and microstructural inconsistencies, affecting component strength and ductility. Recent studies focus on microstructural analysis and mechanical properties, revealing varied microstructures due to distinct heat cycles. Research indicates consistent hardness across WAAM-fabricated components, with variations based on microstructural constituents. Optimizing the WAAM process involves understanding these characteristics and refining welding parameters. Advances in WAAM technology promise significant improvements in manufacturing efficiency, cost-effectiveness, and component quality across various industries.

Microstructure and mechanical properties of high nitrogen austenitic stainless steel welded joints using tandem gas metal arc welding

Abstract High nitrogen austenitic stainless steel welded joints were obtained by gas metal arc welding and tandem gas metal arc welding, respectively. Compared with single wire welded joint, tandem welded joint was investigated. Although tandem welding has less welding pass than single wire welding, higher heat input and cooling rate are obtained. High heat input is the main impact factor on low fraction of δ-ferrite and high fraction of precipitates formed during tandem welding. Moreover, weld seam after tandem welding has higher dislocation density and Schmid factor along δ-ferrite, which results in the reduced tensile strength and yield strength, as presented in mechanical property testing. Less difference of elongation is obtained between single wire welding and tandem welding, as is consistent with Taylor factor results.

A Review On Multi objective Optimisation of Process Parameters in Shielded Metal Arc Welding For Joining Stainless Steel 3041 And Mild Steel 1018

Due to Mechanical properties of the welding metal and heat affected zone (HAZ) is quality of welding in this research work the review of Multi-objective optimization of welding process parameters for obtaining best weld strength with good mechanical properties of dissimilar metals like stainless steel 3041 and Mild steel 1018 is done. This process used for welding is shielded Metal Arc welding and dissimilar metal are stainless steel 3041 and mild steel 1018. Welding speed, depend on electric property like current Voltage electrode angle, feed rate, Arc length are taken as controlling variables. The weld strength (N/mm2) and Bead geometry variables and Heat Affected Zone are obtained by set of experiment, the possible best outcomes and best method has been chosen by this research. Keywords: HAZ, Multi objective optimization, Response surface Methodology, Shielded metal arc welding

تقييم عيوب اللحام في خطوط أنابيب البترول باستخدام الأشعة السينية لتقنيات MAG وTIG وSMAW

The integrity of weld joints in petroleum pipelines is critical to ensuring the safe and efficient transport of fluids. This study evaluates the welding quality of pipes using Shielded Metal Arc Welding (SMAW), Gas Metal Arc Welding (MAG), and Gas Tungsten Arc Welding (TIG) methods. Thirty-six pipe samples were prepared and welded in the 6G position for each technique. X-ray computed tomography was employed to detect and analyze internal weld defects, adhering to ASME standards for acceptability. Defects such as porosity, incomplete penetration, and undercutting were identified, significantly impacting weld quality. Samples exhibiting major defects were rejected, while others met the acceptance criteria. The study underscores the necessity of advanced imaging techniques for accurate defect detection, thereby enhancing weld quality and reliability in pipeline applications. These findings provide valuable insights for improving welding practices, ultimately contributing to reliable and more efficient pipeline systems. Keywords: weld defect evaluation, petroleum pipelines, X-Ray imaging, SMAW, MAG, TIG techniques

Microstructure and corrosion characteristics of AA5083 alloy weld beads produced by GTAW and SpinArc-GMAW

Microstructure and corrosion characteristics of AA5083 alloy weld beads produced by GTAW and SpinArc-GMAW

Effects of random meso‐defects on fatigue behavior of welded joints: Damage evolution and lifetime prediction

AbstractRandom meso‐scale defects within welded joints can affect the structural damage process and cause dispersion in the fatigue lifetime of welded joints. In this paper, a meso‐scale stochastic damage approach is used to investigate the effect of random, meso‐scale defects on the fatigue damage lifetime of welded joints under different loads. First, we established an elastic–plastic fatigue damage model considering meso‐defects in the weld metal. Secondly, the fatigue lifetimes for gas tungsten arc welding and gas metal arc welding welded joints were predicted, with most of the predictions within the twofold dispersion factor. Thirdly, the Monte Carlo simulation method was used to investigate the influence of meso‐defect size on the fatigue lifetime dispersion degree, and the fatigue lifetime distribution under different loads was statistically analyzed.

INVESTIGATION OF THE EFFECT OF SMAW PARAMETERS ON PROPERTIES OF AH36 JOINTS AND THE CHEMICAL COMPOSITION OF SEAWATER

Underwater wet welding (UWW) is a critical technique for repairing offshore structures, underwater pipelines, water transport infrastructure, docks, and harbor equipment. In this study, the mechanical and microstructural properties of AH36 low-carbon steel weldments were investigated using metal arc welding (SMAW), an underwater wet welding method, at various welding current strengths and seawater temperatures. The relationship between changes in seawater temperature and welding current parameters and their impact on seasonal variations in welding conditions and seawater composition was examined. In the first stage, the yield strength of AH36 was statistically modeled using a central composite design with input parameters of seawater temperature (ranging from 9.7 °C to 25.3 °C) and weld current value (ranging from 49A to 90A). Optimal conditions were determined, resulting in a yield strength of 270MPa, achieved at a seawater temperature of 17.5 °C and a weld current value of 69.5 A. In the second stage, data from optimization studies were utilized to develop elemental exchange equations for Cr (R2=87.3), Ni (R2=64.45), and Mn (R2=65.74) ions in seawater. The findings reveal that weld current intensity primarily influences changes in Cr content in seawater, seawater temperature is correlated with Ni content, and both current intensity and seawater temperature affect the Mn content. The analytical techniques employed include Inductively Coupled Plasma Mass Spectrometry (ICP-MS) for seawater ion analysis, Energy Dispersive Spectroscopy (EDS) point analysis to determine the chemical composition of AH36, and Scanning Electron Microscopy (SEM) for microstructural analysis.

Analisa Hasil Sambungan Las ( Pipa STKM 13B Dan Plat SPH 440) Dengan Pengujian Tarik dan Photomacro

ABSTRACTGMAW (Gas Metal Arc Welding) is a fast, versatile welding technique that can be used in various positions, but it often results porosity in welded joints.This research aims to analysis of the welded joints of STKM13B pipe and SPD 440 plate using tensile and micro testing, using welding a current of 18 and varying voltages of 110, 130, and 150. The results is the shape of the welded joint of the plate and pipe is perfectly connected, the tensile test results showed that the ultimate strength values for specimen 1, 2, 3 (A110/V18, A130/V18, A150/V18) were (18,959, 27,886, 40,005 N) respectively. The highest ultimate strength values were obtained from the specimens (A150/V18) while the lowest ultimate strength value was obtained from specimen (A110/V18). The use of welding current strongly correlates with ultimate strength value and photomacro results, with higher currents resulting in higher density levels, minimizing porosity, and increasing ultimate strength. Keywords: GMAW Welding, Tensile Test, Macro Optical Test.

Оценка сварочно-технологических свойств электродных покрытий основного типа различных производителей электродов для сварки трубных деталей и сборочных единиц поверхностей теплообмена котлоагрегатов

Introduction. New grades of high-strength steels, machining and repair processes are being introduced in the power industry. At the same time manual arc welding remains the main technological process for equipment repair in conditions of thermal power plants. Welding materials used in equipment repair should provide comparable to the base metal mechanical properties of the weld. The welding industry has long faced the problem of high sensitivity of basic type electrodes to moisture absorption. High susceptibility to cold cracking caused by diffusible hydrogen and hydrogen embrittlement are major obstacles to the wider use of basic-type electrodes for high-strength steels. Hydrogen production during arc welding is the result of the presence of hydrogen in the arc atmosphere, hydrogen-contaminated filler material, or local hydrogen residues on the source material. During welding, molecular hydrogen is dislocated by the arc energy and then easily absorbed by the molten material. Currently, the welding materials market produces electrodes with basic coating of well-known and proven brands, various national and foreign manufacturers. However, in practice there are cases of cold cracks in the weld seam after welding. Purpose of work is to assess the welding and technological properties of basic type electrode coatings of different manufacturers. The work investigates specimens weld overlaid with electrodes TMU-21U, TSU-5 of different manufacturers and the content of diffusion-mobile hydrogen in the weld overlaid metal is determined. The methods of research are mechanical static tensile tests, chemical composition analysis and metallographic studies. Determination of welding-induced hydrogen content can be accomplished by various quantitative elemental analysis methods. All test methods involve welding under defined conditions followed by deep freezing of the test specimens as quickly as possible. In this way, unintended diffusion processes are inhibited and the hydrogen introduced into the weld metal is retained. Subsequently, the diffusing hydrogen is desorbed from the test specimens in a controlled manner. Results and Discussion. An assessment of welding engineering properties of the electrodes revealed unstable arc burning. Mechanical properties of the welded metal of the investigated electrodes are at the minimum permissible level from the requirements of normative documents. The concentration of hydrogen present in the arc weld metal is multifactorially dependent on the welding procedure (process and parameters, consumables used, as well as environmental conditions (e.g. humidity). For qualitative assessment, hydrogen content of more than 15 cm3/100 g is considered high and hydrogen content less than 5 cm3 ml/100 g is considered very low. Presented results. The conducted evaluation of welding engineering properties of electrodes with basic coating showed satisfactory results. Mechanical properties of the welded metal in terms of impact toughness are at the lower permissible limit, relative elongation does not meet the requirements of normative documents. The content of diffusion-mobile hydrogen in the welded metal is higher than the declared indicators by the electrode manufacturers.

Combined Gas Tungsten Arc Welding and Shielded Metal Arc Welding Processes for Joining Tube to Tubesheet in Shell and Tube Heat Exchangers

Abstract Flawless tube and tubesheet joints are necessary for shell and tube heat exchanger with high leakproof ability and durability. The consequence of mixing of transfer fluids due to the defective welded or expanded tube-to-tubesheet joint results in complete malfunctioning of the heat exchange process. In this case, there is a high demand for quality assessment of the fabricated tube-to-tubesheet joints (TTS) based on the international standards. Additionally, the literature on assessing the mechanical and metallurgical characteristics of tube-to-tubesheet joints using any one welding technique is available; however, articles dealing with the use of multiple welding techniques are scanty. In the current work, the quality assessment of strength welded and light expanded (3%) tube-to-tubesheet joints followed by light expansion was performed whereas for welding, combined gas tungsten arc welding (GTAW) and shielded metal arc welding (SMAW) as root pass and cap pass were adopted in the fabrication stage. Quality and sound tube-to-tubesheet joints were produced using welding and tube expansion process. Linear and circular indications representing the cracks were absent on the developer in the liquid penetration test. The minimum leak path (MLP) was greater than the two-third of tube wall thickness. The results strongly qualify the use of combined gas tungsten inert gas and shielded metal arc welding process for manufacturing of tube-to-tubesheet joints. The methodology and results in the current article are beneficial for researchers and industrialists working close to shell and tube heat exchangers and boilers.

Microstructural characteristics and properties of wire arc additive manufactured 304L austenitic stainless steel cylindrical components by different arc welding processes

Microstructural characteristics and properties of wire arc additive manufactured 304L austenitic stainless steel cylindrical components by different arc welding processes

Evaluation of Melting Efficiency in Cold Wire Gas Metal Arc Welding Using 1020 Steel as Substrate

A key welding parameter to quantify in the welding process is the ratio of the heat required to melt the weld metal versus the total energy delivered to the weld, and this is referred to as the melting efficiency. It is generally expected that the productivity of the welding process is linked to this melting efficiency, with more productive processes typically having higher melting efficiency. A comparison is made between the melting efficiency in standard gas metal arc welding (GMAW) and cold wire gas metal arc welding (CW-GMAW) for the three primary transfer modes: short-circuit, globular, and spray regime. CW-GMAW specimens presented higher melting efficiency than GMAW for all transfer modes. Moreover, an increase in plate thickness in the spray transfer regime caused the melting efficiency to increase, contrary to what is expected.

Microstructure, mechanical properties and sensitization of ultra-low nickel Cr–Mn austenitic stainless steels

Microstructure, mechanical properties and sensitization of ultra-low nickel Cr–Mn austenitic stainless steels

해양구조물용 YS 420MPa 강재 Flux Cored Arc 용접금속의 기계적 성질에 미치는 용접 자세의 영향

This study investigated the mechanical properties of flux-cored arc weld metal of 420-MPa yield-strength (YS) steels for offshore structures based on welding position. Results showed that the recovery rate of alloying elements in the horizontal-position weld metal was higher than that in the vertical-up-position weld metal, and the fraction of low-temperature transformation phases with high dislocation density in the horizontal-position weld metal was high. Consequently, the YS, tensile strength, and impact toughness of the horizontal-position weld metal were higher than those of the vertical-up-position weld metal. In addition, the impact toughness of the weld metal was affected to a greater extent by the microstructure and fraction of the weld metal itself than by the fraction of the martensite-austenite constituents.

An innovative pulsed current arc welding technology for armor steel: Processes, microstructure, and mechanical properties

An innovative pulsed current arc welding technology for armor steel: Processes, microstructure, and mechanical properties

In situ measurement of hydrogen concentration in steel using laser-induced breakdown spectroscopy (LIBS)

AbstractThe ISO 3690 standard “Determination of hydrogen content in arc weld metal” requires a thermal activation of the diffusible hydrogen in a piece of weld metal for the subsequent ex situ concentration measurement by carrier gas hot extraction CGHE or thermal desorption spectroscopy (TCD). Laser-induced breakdown spectroscopy (LIBS) offers a time and spatially resolved, almost non-destructive, in situ measurement of hydrogen at surfaces without sample preparation. We measured hydrogen in steels, which were charged either electrochemically or by high-pressure hydrogen gas, and compared the results. Further, the feasibility of quantitative hydrogen line scan measurements with LIBS was demonstrated by measuring hydrogen at water jet cut surfaces. The hydrogen concentrations measured with the help of LIBS were compared with CGHE measurements. It was observed that hydrogen can be reliably measured with LIBS for concentrations larger than 2 wt.-ppm. The maximum hydrogen concentration achieved using electrochemical charging was 85.1 ppm. The results show that LIBS is a promising technique for time- and spatially resolved measurements of hydrogen in steels.