Showing papers on "Arc welding published in 2023"

Process Simulation and Optimization of Arc Welding Robot Workstation Based on Digital Twin

Abstract: For the welding cell in the manufacturing process of large excavation motor arm workpieces, a system framework, based on a digital twin welding robot cell, is proposed and constructed in order to optimize the robotic collaboration process of the welding workstation with digital twin technology. For the automated welding cell, combined with the actual robotic welding process, the physical entity was digitally modeled in 3D, and the twin welding robot operating posture process beats and other data were updated in real time, through real-time interactive data drive, to achieve real-time synchronization and faithful mapping of the virtual twin as well as 3D visualization and monitoring of the system. For the robot welding process in the arc welding operation process, a mathematical model of the kinematics of the welding robot was established, and an optimization method for the placement planning of the initial welding position of the robot base was proposed, with the goal of smooth operation of the robot arm joints, which assist in the process simulation verification of the welding process through the virtual twin scenario. The implementation and validation process of welding process optimization, based on this digital twin framework, is introduced with a moving arm robot welding example.

Difficulties and redressal in joining of aluminium alloys by GMA and GTA welding: A review

Abstract: The article reviews the difficulties and its redressal in fusion welding (especially the most used welding processes in the industry; gas metal arc (GMA) and gas tungsten arc (GTA) welding) of aluminium alloys. The more excellent thermal conductivity, solidification shrinkage, oxide formation, and thermal expansion coefficient cause more difficulties welding aluminium alloy than other materials. Welding parameters (such as welding current, welding voltage, shield gas flow rate, welding speed, torch location, etc.) have a complicated and non-linear relationship with the weld's quality and the joint's mechanical characteristics. Several techniques are suggested for improved weld quality and joint strength, including pulsing the current, post-weld heat treatment, proportional mixing of the shielding gases, speedy shielding gas injection, and many more. Due to various materials varied chemical and thermal characteristics, the GMA and GTA welding of dissimilar aluminium alloy exhibits more difficulties. To get around the challenges, adjusting the torch position and choosing a filler material that works with both aluminium alloys are practiced.

Pengujian Pengelasan Plat Stainless Steel JIS SS304 Menggunakan Mikro Struktur

Abstract: Failure in the welding process will result in a drop in quality and a risk to worker safety. Small cavities were frequently detected during welding. In order to identify the origin of the damage, the goal of this study is to investigate the presence of small circular cavities that are grouped in the welding region of gas tungsten arc welding (GTAW) welding outcomes. The research technique involves categorizing changes in electric current on JIS SS 304 stainless steel material with a thickness of 10 mm: GTAW 80 A root (low current), 100 A Filler (mid electric current), and 120 A Capping (high current). Based on investigations into the use of electric current for Gas Tungsten Arc Welding (GTAW) welding and the interpretation of discontinuity in the outcomes of welding on JIS SS 304 stainless steel material, on JIS SS 304 plate material with a thickness of 10 mm. learn about the welding methods GTAW and HAZ GTAW at the point of the microstructure as components that have thermal impacts

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

Abstract: Abstract 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 TiB 2 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 TiB 2 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.

Solid-state welding

Abstract: The chapter presents the definitions and essence of cold welding, ultrasonic welding, and explosion welding. Shows schemes and main parameters of the welding processes, recommendations on their selection, features, and mechanisms of welded joints formation. Also, explains the influence of processes technological parameters, and welding conditions on metallurgical processes, formation of structure, and properties of welded joints. Moreover, presents the structure of welding equipment, advantages, disadvantages, and areas of application of the methods, product examples.

An introduction to welding of metallic materials

Abstract: In this chapter, a short history of the welding process is given, in addition to the stages that welding processes were developed in the last century until now. A brief introduction of the principles of different types of welding processes based on the used source of energy is shown. Different types of welding processes are explained briefly. More details about manual metal arc welding are given as an example of arc welding. The metallurgical aspects and weldability of the metals, steel-based alloys, in particular, are explained, especially in fusion welding processes, with or without using filler metals, considering the effect of the chemical composition and microstructures of the fusion zone and heat-affected zone on the whole behavior of the weldments. General welding defects in metallic alloys are shown either in the fusion or solid-state welding methods. Moreover, pre and/or postheat treatments, to minimize the defects and residual stresses are shown. Appropriate testing methods to evaluate the mechanical and corrosion behavior of the weldments are explained. At the end of the chapter, the general advantages and disadvantages of welding processes are listed.

Fundamentals of Dissimilar Metal Joining by Arc and Resistance Welding Processes

Abstract: This chapter presents the fundamentals, causes and remedies related to the common issues (asymmetric weld, unmixed zone, intermetallic compound, cracking of weld and HAZ, residual stress and distortion) encountered in joining of dissimilar metals combinations by arc, resistance welding. Fusion welding processes, namely GTAW, Pulse, cold metal transfer and Narrow gap variants of GMAW, SMAW and SAW, have been described considering the dissimilar metal joining. Additionally, dissimilar metal joining using brazing and braze welding has also been elaborated.

Investigation of the Mechanism of Powder Pool Coupled Activating TIG Welding

Abstract: As a highly effective welding method, PPCA-TIG (Powder Pool Coupled Activating Flux–Tungsten Inert Gas) welding aims to achieve automated activation of TIG welding through the use of suitable activating fluxes. However, due to the unique transitional behavior of activating elements, the mechanism of PPCA-TIG is a little bit different from common activating TIG welding. In this research, a two-dimensional model is established to investigate the effect of four activating fluxes (TiO2, SiO2, MnO2, CaF2) on arc morphology and force. A series of welding experiments is performed to study the impact of the different activating elements on the molten pool. The results show that the increase in the penetration of TiO2 is related to the high arc temperature and great arc force and electromagnetic force in the molten pool. The problem of the softening of 3003 aluminum alloy welded joints is solved. Other activating fluxes are less effective than TiO2. The addition of calcium fluoride significantly affects penetration. The use of TiO2, SiO2 and MnO2 changes the molten pool viscosity and affects the molten pool oscillation, thus affecting the weld quality.

Co-processing of hybrid laser arc welding (hlaw) & submerged arc welding (saw) for enhancing productivity in thick high strength steel joints

Abstract: The shipbuilding and heavy manufacturing industries are looking for a novel welding technique to weld high-strength steel alloys with thicknesses above 25 mm. Submerged arc welding (SAW) has been the “go-to” joining process for thick material from both sides. However, using SAW alone requires thick plates to be flipped over multiple times during welding to minimize the effects of distortion and uses a large volume of weld metal. This paper presents research on the feasibility of welding thick, high-strength steel plates in a combined, sequential processing approach utilizing HLAW and SAW. The development activity entails HLAW processing the weld joint’s first pass to achieve an approximate 18 mm root penetration, followed by SAW to complete the joint (38 mm). Mechanical properties, impact toughness, and microhardness hardness distribution in specific zones of one side butt multiple pass welded joints are analyzed in correlation with a microstructure in specific zones of the welded joint. The paper also discusses the applicable standards and recommendations for welding those steels, from the aspect of applications in the design of steel welded constructions. Based on the carried-out analysis and results obtained in experiments, the applied welding technology minimizes the volume of weld metal needed to complete the joint. It achieves requisite performance mechanical properties while reducing material preparation costs and labor. This joining process approach is expected to increase capabilities for shipbuilding, heavy manufacturing, and oil and gas industries.

Submerged arc welding and melting technology

Abstract: The article dedicated "Submerged arc welding and meltıng technology" method, which is one of the technologies for repairing friction-worn parts of oil and gas equipment. The efficiency, technological regime,advantages of the process are noted, and it is also shown that this method is used today in the oil industry and shipbuilding. With these methods, the repairing of a part of the pieces corroded by friction, as well as the possibility of welding steel plates of different grades and thicknesses, was reflected. In determining welding procedures for certain applications, the welding engineer must first take into account the specific welding qualities required, since in practice, although some factors can be determined quite accurately, others change during manufacturing process. Arc voltage, electrode selection, welding speed are important considerations in determining operating mode, and the penetration caused by high voltage combined with low speed is indicated accordingly. The supply of agent (glycerin) to the recently created attachment zone is indicated. It reduces the thermal impact of the cooling arc on the half and will increase the cooling rate of the deposited and metal, decreasing the deformation and self-heating of the adjacent elements of the half. Besides, the liquid serves to safeguard the liquid metal from the harmful effects of chemical element and gas. Keywords: overheating, vibration, crack, arc voltage, welding defects, welding speed, technical glycerin, soda ash.

Plasma welding of thin-wall tubes

Abstract: Investigative results and their practical application of the electric-arc microplasmatron for the thin-wall tubes welding are shown in the paper presented. Conditions for the qualitative seam welding are being discussed. The main attention is being paid to optimization of the discharge parameters and geometrical sizes of the tungsten cathode and the forming nozzle. The main reasons for arc shunting between the cathode and the nozzle were determined. To estimate the optimal values of the current, and to chose the diameters of the rod electrode and the nozzle, some original formulas are being suggested. Several practical recommendations are given to improve the plasma technology of the tubes welding.

Analysis of the process of qualifying the welding technology of S355JR structural steel using the submerged arc welding method

Abstract: This paper presents the issue of welding technology qualification using the example of structural steel S355JR with a plate thickness of 25 mm and 100 mm, bevelling V. The main objective of this work was to attempt to perform a full qualification of the submerged arc welding process in accordance with the requirements of PN EN ISO 15614. Particular attention was paid to the issue of the qualification of welding technology. The samples were subjected to non-destructive testing, i.e. visual and penetrant testing, as well as ultrasonic testing and heat treatment. This was followed by destructive testing, including macroscopic testing and hardness testing. According to the proposed procedure for the recognition of submerged arc welding technology, once the necessary tests had been carried out and the protocols with positive results had been obtained. The documentation had been completed, the analysis needed to obtain certificates of conformity for factory production control and welding quality was carried out.Submerged arc welding is often used for highly responsible butt joints, particularly when joining thick components. This has been achieved through the proper design of the preparation of the parts to be welded and the development of a welding technology that practically eliminates the pre-phase that occurs in traditional technology, thereby eliminating the risk of it affecting the quality of the welded joint.During the implementation of submerged arc welding, a number of technological problems were encountered. The first test joints contained many defects, i.e. sticking and slag inclusions inside the welds. In addition, obtaining welds with the correct profile and removing the slag from the weld groove was difficult. These obstacles were eliminated experimentally by carrying out successive tests using different parameters and welding groove geometries.The correct implementation of any welding process depends on its input parameters. These parameters include welding current, welding speed, welding current, wire diameter, welding voltage and many others. Submerged arc welding (SAW) is widely used in the industry for manufacturing as it is more reliable, provides deep penetration in the work, ensures a smooth finish on objects, and results in high productivity.The technology was developed for a company that manufactures control discs for steam turbines.

Electrosmelting control in arc furnace and ladle furnace with continuous supply of iron raw materials into the weld pool

Abstract: The paper presents energy and technological indicators and designs of improved electric furnace units for melting steel from iron ore raw materials (IOR). A method of controlling an arc furnace with a continuous IOR supply is proposed, which gives the opportunity to control and regulate the active power of the furnace, thermal processes in the welding bath of the electric arc, as well as in the unit as a whole. The design of a ladle unit for out-of-furnace melt treatment is presented, which allows the melting of high-quality electrical steel and simultaneous treatment with inert gases. At the same time, it is possible to reduce the metal carbon monoxide and IOR melting time.

Environmental and Economic Analyses of TIG, MIG, MAG and SMAW Welding Processes

Abstract: Metal welding processes, and electric arc welding in particular, constitute a key link in a production chain comprising a large number of companies. This fact, in addition to a growing trend in favour of more in-depth environmental analysis and control of industry, and the need to continue affording due consideration to the economic aspect set the stage for this study. Herein, an environmental and economic analysis is conducted of four types of electric arc welding: TIG welding with and without filler, MIG, MAG, and SMAW welding. Different types of materials are examined such as carbon steel, stainless steel, and aluminium, thus the results generate relevant comparative information on the economic and environmental impacts of choosing one type of welding over another. To this end, an experimental study was carried out: 480 test specimens were welded using different welding technologies. A series of data was collected during the welding process to inform an environmental analysis based on a Life Cycle Analysis and an economic study. The most salient results include that the TIG welding process with filler generated the greatest environmental impact due to its higher consumption of shielding gas. On the other hand, the SMAW process demonstrated the best environmental performance as categories such as Global Warming Potential; CO2 emissions dropped by 93.29%. A key factor is the final indicator of human health, where, once again, TIG technology had the worst results, in contrast to SMAW technology, wherein impact decreased by 93.08%. On the other hand, the use of TIG technology implies a higher economic cost due to a 61.36% increase in welding time compared to the average welding technology.

Fundamental Study on Influence of Oxidation and Nitridation on Mechanical Properties of Commercially Pure Titanium Fabricated by Wire-Arc Additive Manufacturing

Abstract: Recently, additive manufacturing has been receiving considerable attention as a cost-effective technology compared to traditional manufacturing methods for its capability of fabricating complex parts directly from feedstock materials. In order to investigate possibilities of wire-arc additive manufacturing of commercially pure titanium by metal inert gas welding under atmospheric condition, fundamental experiments mainly focusing on contamination during welding process and its influence on mechanical properties of welded metal were conducted. From such experimental results, it was clarified that nitridation attributes largely to hardening and embrittlement of welded metal. Moreover, it was shown that promoting retention of shielding gas from welding torch or after shielding nozzle may be an effective solution to lower such risk of contamination or embrittlement problem.