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Purpose
The purpose of this paper is to analyze the characteristics of sound during gas tungsten argon welding (GTAW), which is very important to effectively monitor the welding quality in future by using the information extracted from sound.
Design/methodology/approach
The hardware used in the experiment is described. Then the paper researches the influence of welding techniques (gas flow, welding speed, welding current, and arc length) on arc sound and the distribution of the welding sound field. Finally, the relation between welding power and sound are studied based on Fourier transforms and recursive least square methods.
Findings
The sound pressure is affected greatly by gas flow, arc length, and current; welding sound source obeys the dipole model; the sound can be better predicted when the three orders derivative of the welding power are combined together.
Originality/value
This paper provides a new insight into welding sound resource model and a detailed analysis of the influence of the welding sound caused by welding techniques.
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Keywords
Ugur Caligulu, Mustafa Taskin, Haluk Kejanli and Ayhan Orhan
The purpose of this paper is to investigate interface characterization of CO2 laser welded AISI 304 austenitic stainless steel and AISI 1010 low carbon steel couple. Laser welding…
Abstract
Purpose
The purpose of this paper is to investigate interface characterization of CO2 laser welded AISI 304 austenitic stainless steel and AISI 1010 low carbon steel couple. Laser welding experiments were carried under argon and helium atmospheres at 2000, 2250 and 2500 W heat inputs and 200‐300 cm/min welding speeds.
Design/methodology/approach
The microstructures of the welded joints and the heat affected zones (HAZ) were examined by optical microscopy, SEM, EDS and X‐Ray analysis. The tensile strength of the welded joints was measured.
Findings
The result of this study indicated that the width of welding zone and HAZ became much thinner depending on the increased welding speed. On the other hand, this width widened depending on the increased heat input. Tensile strength values also confirmed this result. The best properties were observed at the specimens welded under helium atmosphere, at 2500 W heat input and at 200 cm/min welding speed.
Originality/value
There are many reports which deal with the shape and solidification structure of the fusion zone of laser beam welds in relation to different laser parameters. However, the effect of all influencing factors of laser welding has up to now not been extensively researched. Much work is required for understanding the combined effect of laser parameters on the shape and microstructure of the fusion zone. This paper, therefore, is concerned with laser power, welding speed, defocusing distance and type of shielding gas and their effects on the fusion zone shape and final solidification structure of some stainless steels.
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P. Sathiya, M.Y. Abdul Jaleel and D. Katherasan
This study aims to determine the near optimal welding process parameters (beam power (BP), travel speed (TS) and focal position (FP)) using grey relational analysis by…
Abstract
Purpose
This study aims to determine the near optimal welding process parameters (beam power (BP), travel speed (TS) and focal position (FP)) using grey relational analysis by simultaneously considering multiple output parameters (depth of penetration and bead width). Further, the optimized parameters were evaluated through the microstructural characterization and hardness measurements across the weld zone.
Design/methodology/approach
It is appropriate to apply Taguchi's technique to a complex system like welding process. Therefore, this study is made to determine the near optimal welding process parameters (BP, TS and FP) using grey relational analysis by simultaneously considering multiple output parameters (depth of penetration and bead width).
Findings
Taguchi experimental design for determining welding parameters was successful. The hardness of the Argon shielded weld metal was comparatively lesser than the Helium shielded weld metal. The Helium shielded weld metal microstructure comprises of finer grains and higher amounts of equiaxed grains. Argon and Helium shielded weld metal microstructure was endowed with a higher amount of secondary interdendritic austenite phase.
Originality/value
The optimal welding conditions were identified in order to increase the productivity and minimize the total operating cost. The process input parameters effect was determined under the optimal welding combinations.
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Elisaveta Doncheva, Nikola Avramov, Aleksandra Krstevska, Martin Petreski, Jelena Djokikj and Marjan Djidrov
Welding is a widely used manufacturing process in many industries. The process consumes a lot of energy and resources, pollutes the environment, and emits gases and fumes into the…
Abstract
Purpose
Welding is a widely used manufacturing process in many industries. The process consumes a lot of energy and resources, pollutes the environment, and emits gases and fumes into the atmosphere that are dangerous to human health. There are various welding processes, and the suitable welding process is usually chosen based on cost, material, and conditions. Subjectivity is the most significant impediment to selecting an optimal process. As a result, it is critical to develop the appropriate set of criteria, use the best tool and methodology, and collect sufficient data. This study examines the sustainability of welding processes and their environmental impact.
Design/methodology/approach
The welding process’s sustainability was examined and discussed in general, considering the technological specifics of each welding process, physical performance, and environmental, economic, and social effects. The study investigates the environmental impact of MMAW, GMAW, and GTAW/GMAW processes through experimental work and LCA methodology.
Findings
MMAW is the most environmentally harmful technology, whereas GMAW has the least impact. The GTAW/GMAW process outperformed the other processes in terms of yield stress, but the analyses revealed that it had a greater environmental impact than GMAW.
Originality/value
The study provides an environmental impact summary and demonstrates the effects of welding parameters and processes. This gives users an understanding of choosing the best welding technique or making the process more environmentally friendly. These recommendations help policymakers identify hot spots and implement the right plans to achieve more sustainable manufacturing.
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Teodiano Freire Bastos, L. Calderón, J.M. Martín and R. Ceres
Evaluates the applicability of ultrasonic sensors in a welding environment and reports on experimental measurements carried out with a sensory head containing ultrasonic…
Abstract
Evaluates the applicability of ultrasonic sensors in a welding environment and reports on experimental measurements carried out with a sensory head containing ultrasonic transducers with different frequencies. Analyses the effects on the sensors of factors such as noise, temperature and shielding gas flow and concludes by suggesting appropriate protective measures for the sensors for them to operate effectively in a welding environment.
Paulraj Sathiya, M.Y. Abdul Jaleel and B. Shanmugarajan
Laser welding under high power, high degree of automation and high production rate is extremely advantageous in automotive application. Super austenitic stainless steel is the…
Abstract
Purpose
Laser welding under high power, high degree of automation and high production rate is extremely advantageous in automotive application. Super austenitic stainless steel is the preferable material for high corrosion resistance requirements. These steels are relatively cheaper than austenitic stainless steel and it is expensive than nickel base super alloys for such applications. The main purpose of this paper is to present the investigations of the microstructure and mechanical properties of super austenitic stainless steel butt joints made by 3.5 kW cooled slab CO2 laser welding using different shielding gases such as argon, nitrogen and helium.
Design/methodology/approach
The tensile and impact tests were performed and the fractured surfaces were analyzed by scanning electron microscope. The hardness across the joint zone was measured. The X‐ray diffraction technique was used to analyze the phase composition. The microstructure of the laser welds were analyzed through optical microscopy.
Findings
The tensile sample fractures indicate that the specimen fails in a ductile manner under the action of tensile loading. The impact fracture surfaces of the different shielding gas laser welded joints show mixed mode fractures, that is, ductile and cleavage fractures. The hardness values of the Helium shielded laser joints in the weld metal regions are much higher than the others.
Research limitations/implications
There is no limitation, except for the availability of the high beam power laser welding machine.
Practical implications
The only practical implication is the laser welding shop hazard during the experiment.
Social implications
Social implication is limited. The only hazard during the laser welding is that it may affect human body tissues.
Originality/value
The research work described in the paper is original.
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Somrerk Chandra-Ambhorn, Sompong Chueaprakha and Thamrongsin Siripongsakul
The dissimilar welds between AISI 304L and Fe-15.6Cr-8.5Mn were investigated on oxidation at 700°C with the effects of dissolved nitrogen in the welds. This paper aims to clarify…
Abstract
Purpose
The dissimilar welds between AISI 304L and Fe-15.6Cr-8.5Mn were investigated on oxidation at 700°C with the effects of dissolved nitrogen in the welds. This paper aims to clarify the oxidation behaviors to expand the range of application for Fe-Cr-Mn stainless steel.
Design/methodology/approach
Dissimilar welds between AISI 304L and Fe-15.6Cr-8.5Mn were fabricated using gas tungsten arc welding to investigate the oxidation behavior of the welds at 700°C. Pure Ar and Ar-4%N2 shielding gases were used to evaluate the effects of nitrogen gas. The welds were introduced to the cyclic oxidation test. In each cycle, the furnace was heated up to 700°C, and the temperature was kept at 700°C for 8 h, then the mass gain because of oxidation was examined. The scales after oxidation test were investigated by using scanning electron microscopy with EDX and X-ray diffraction analysis.
Findings
Addition of 4 per cent nitrogen to Ar shielding gas reduced delta-ferrite content in the weld. Ar-4%N2 shielding gas resulted in dissolved nitrogen which helped increase the diffusivities of chromium or oxygen vacancies in the oxide to facilitate the chromia formation at the inner part near the steel substrate. This protective layer can help reduce the Fe outward diffusion, thus reducing mass gain because of iron oxide formation.
Originality/value
The oxidation behavior of dissimilar welds between AISI 304L and Fe-15.6Cr-8.5Mn were investigated at 700°C. The evaluation is beneficial for expanding the range of application of Fe-Cr-Mn stainless steel at high temperature.
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Tunde Isaac Ogedengbe, Taiwo Ebenezer Abioye and Augusta Ijeoma Ekpemogu
The purpose of this study is to conduct gas tungsten arc dissimilar welding of AISI 304 stainless steel and low carbon steel within a process window so as to investigate the…
Abstract
Purpose
The purpose of this study is to conduct gas tungsten arc dissimilar welding of AISI 304 stainless steel and low carbon steel within a process window so as to investigate the effects of current, speed and gas flow rate (GFR) on the microstructure and mechanical properties of the weldments.
Design/methodology/approach
The welding experiment was carried out at different combinations of parameters using WN-250S Kaierda electric welding machine. A combination of scanning electron microscopy and energy dispersive X-ray spectroscopy was used to examine the microstructure of the weldments. Micro-hardness and tensile tests were performed using Vickers hardness tester and Instron universal testing machine, respectively. ANOVA was used to analyze the significance of the parameters on the mechanical properties.
Findings
The microstructure of the weld region is characterized with dendritic structure with the existence of ferrite and austenite phases. The utilized parameters show significant effects on the ultimate tensile strength (UTS) of the weldments. The current and GFR were found to be the most and least significant factors, respectively. Both the grain size and weld penetration contributed to the UTS of the weldments. The UTS (427-886 MPa) increased with decreasing current and welding speed. In all samples, the weld region exhibited higher hardness (297-396 HV) than the HAZ in the base metals (maximum of 223 Â ± 6 HV). All the three factors show significant effect with the welding speed contributing mostly to the hardness of the weld region.
Originality/value
The parametric combination that gives the optimum mechanical performance of the dissimilar gas tungsten arc weldments of AISI 304 stainless steel and low carbon steel was established.
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Amruta Rout, Deepak Bbvl, Bibhuti B. Biswal and Golak Bihari Mahanta
This paper aims to propose fuzzy-regression-particle swarm optimization (PSO) based hybrid optimization approach for getting maximum weld quality in terms of weld strength and…
Abstract
Purpose
This paper aims to propose fuzzy-regression-particle swarm optimization (PSO) based hybrid optimization approach for getting maximum weld quality in terms of weld strength and bead depth of penetration.
Design/methodology/approach
The prediction of welding quality to achieve best of it is not possible by any single optimization technique. Therefore, fuzzy technique has been applied to predict the weld quality in terms of weld strength and weld bead geometry in combination with a multi-performance characteristic index (MPCI). Then regression analysis has been applied to develop relation between the MPCI output value and the input welding process parameters. Finally, PSO method has been used to get the optimal welding condition by maximizing the MPCI value.
Findings
The predicted weld quality or the MPCI values in terms of combined weld strength and bead geometry has been found to be highly co-related with the weld process parameters. Therefore, it makes the process easy for setting of weld process parameters for achieving best weld quality, as there is no need to finding the relation for individual weld quality parameter and weld process parameters although they are co-related in a complicated manner.
Originality/value
In this paper, a new hybrid approach for predicting the weld quality in terms of both mechanical properties and weld geometry and optimizing the same has been proposed. As these parameters are highly correlated and dependent on the weld process parameters the proposed approach can effectively analyzing the ambiguity and significance of each process and performance parameter.
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The aim of the research is to investigate the influence of gas metal arc welding on the wear performance of worn concussor jaws.
Abstract
Purpose
The aim of the research is to investigate the influence of gas metal arc welding on the wear performance of worn concussor jaws.
Design/methodology/approach
Worn parts were welded using the gas metal arc welding process. Various wires were used for this purpose. These welded parts were subjected to wear tests under different loads, and changes in the hardness and microstructures were examined. A pin‐on‐disc wear test apparatus was used.
Findings
As a result of this study, the following findings are reported: wear rates were significantly increased with the increasing of load and wear distance; the hardness of the weld metal of the welded specimens changed depending upon the chemical composition of the weld wire; with the increasing carbon, manganese and chromium in the weld wire, wear resistance increased; in the present study, specimens B and C showed better wear resistance; therefore these specimens are suitable for using in concussor jaws.
Research limitations/implications
Electrodes were limited with four wires, for welding gas arc welding methods were applied, loads were limited with 10, 25, 40 N, welded parts were subjected to wear test, hardness test, microstructures were examined.
Practical implications
For future work, instead of buying worn concussor jaws, they are repaired with the gas metal arc welding process using various weld wires. By this process, working life of the jaws can be extended and vast economical benefit may also be obtained.
Originality/value
This paper fulfils an identified information need and offers practical help to the industrial firms working with alunit ore and rock crasher and also to the academicians working on wear of materials.
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