Submerged Arc Welding Process Research Articles

Waste to wealth: Recycling of steel slag as flux for the submerged arc welding process and its effect on mechanical and metallurgical properties of welds

A novel technology has been developed to recycle steel slag as a flux for the submerged arc welding process. The chemical, mechanical, and metallurgical properties of welds produced using recycled slag have been evaluated and compared with that of fresh flux available in the market. The tensile strengths of weld metal prepared with recycled slag and fresh flux are 462.25 MPa and 471.49 MPa, which are comparable. The impact strength of welds produced using recycled slag is 83.66 J which is acceptable in accordance with AWS SFA 5.17 specifications. The welds produced were subjected to non-destructive tests such as radiography and also dye-penetration test apart from visual inspection to ascertain the soundness of welds produced. Metallurgical investigations were carried out, and a favorable microstructure containing acicular ferrite was obtained in welds deposited using recycled slag. Similar trends of microhardness survey have been observed in both the welds produced.

Experimental investigation and optimization of weld bead shape factor and form factor using recycled steel slag as a flux in submerged arc welding process

The quality and productivity of welds produced depend upon the weld bead profile which is represented by weld penetration shape factor (WPSF) and weld reinforcement form factor (WRFF). The weld profile is further dependent upon welding parameters used hence optimization of welding parameters is essential. In this research work, the steel slag has been recycled to act as a flux in submerged arc welding. The effect of process parameters on WPSF and WRFF using recycled slag has been evaluated. The mathematical models have been developed from the data created. It was found that the weld deposited with recycled steel slag performs well as the WPSF and WRFF are comparable with that deposited with fresh flux. The welding parameters have been optimized using the desirability approach and genetic algorithm. The genetic algorithm yielded more accurate results as compared to the desirability approach.

Chemical Interaction of Cr-Al-Cu Metal Powders in Aluminum-Assisted Transfer of Chromium in Submerged Arc Welding of Carbon Steel

In submerged arc welding (SAW) of chromium containing steels, the chromium in the weld metal is usually sourced from weld wire. Manufacturing of precise weld wire compositions for alloying of the weld metal is expensive. In addition, alloying of weld metal with high levels of copper via weld wire is hindered by work hardening of the weld wire. In the SAW process, a large quantity of oxygen is added to the weld pool. Because chromium has a high affinity for oxygen, the oxygen partial pressure at the weld pool-molten flux interface must be controlled to ensure high recovery of chromium to the weld metal. This study illustrates the application of copper as stabilizer, in conjunction with aluminum, to enhance chromium transfer to the weld pool. The stabilizer effect occurs because the Cr-Al-Cu alloy liquidus temperatures are much lower than the pure Cr liquidus temperature. The result is an increase in the total quantity of Cr, Al, and Cu powder melted into the weld pool. The application of Al powder additions to control the partial oxygen pressure at the molten flux-weld pool interface is confirmed in the presence of Cr and Cu metal powders to ensure the weld metal ppm O content is maintained at the acceptable level of 300 ppm.

Modeling and Optimizing the Penetration in the Submerged Arc Welding Process in the Presence of ZrO2 Nanoparticles

Abstract Penetration is one of the most vital parameters because of its influences on weld strength and weld quality. Choosing the input parameters in submerged arc welding (SAW) has significant effects on input heat into the weld pool, which affects the quality of weldment. The amazing advancement of nanotechnology in various industrial areas persuaded researchers to use nanoparticles in new research. Zirconium dioxide (ZrO2) nanoparticles were selected in order to identify their effects in the weld pool in combination with other welding input parameters. The five-level, five-parameter central composite rotatable design, response surface methodology, the slime mold algorithm, and Harris hawks optimization were utilized to design and develop the research and finally to predict and optimize the weld penetration affected by the arc voltage, welding current, nozzle-to-plate distance, welding speed, and the thickness of ZrO2 nanoparticles coated on ST-37 steel. The main and interaction effects of input parameters on weld penetration were drawn. The results demonstrated that weld penetration decreased initially by increasing the thickness of ZrO2 nanoparticles up to 0.25 mm, which was due to reversing Marangoni convection mode. Furthermore, weld penetration increased with increase in ZrO2 nanoparticles above thicknesses of 0.75 mm. The reason for increase in weld penetration was because of the fact the ZrO2 nanoparticles have low thermal conductivity, which leads to less heat transfer. The results confirmed that the accuracy of model obtained by slime mold algorithm was 5.2 % more than response surface methodology.

Submerged arc welding process peculiarities in application for Arctic structures

<abstract> <p>The paper focuses on the submerged arc welding (SAW) process in application to structures for Arctic conditions. One of the technical challenges for modern Arctic structures is to produce high-quality welds since a weld is usually the weakest part of any structure. Welding is especially difficult for the high strength steels (HSS), which are used in structures for weight-reduction purposes. The objective of the study is to explore the usability, development possibilities and parameters of SAW process for welding of thick cold-resistant HSS plates. Meeting this objective required in-depth understanding of the welding and material science background, which includes the quality requirements of weld joints intended for Arctic service as described in various standards, properties of cold-resistant HSS and description of testing methods used to validate welding joints for low temperature conditions. The study describes experimental findings that improve understanding of SAW process of thick quenched and tempered (QT) and thermo-mechanically processed (TMCP) HSS plates. Experiments were conducted to develop SAW procedures to weld several thick (exceeding 25 mm) high strengths (580–650 MPa tensile strength) cold-resistant (intended operational temperature at least −40 ℃) steel grades. The welds were evaluated by a wide range of industrial tests: analyses of chemical, microstructural and mechanical properties; hardness tests; and cold resistance evaluation tests: the Charpy V-notch impact test and the Crack tip opening displacement (CTOD) test. Acceptable welding parameters and recommendations were developed, and the results of the experiments show that high quality welds can be obtained using heat input up to 3.5 kJ/mm.</p> </abstract>

Optimization of process parameters on weld bead characteristics of mild steel in submerged arc welding process

In this paper, an endeavor has been taken to contemplate the process parameter optimization on weld bead characteristics in submerged arc welding. The width of heat affected zone, width of weld bead, area of penetration, depth of penetration and reinforcement height are the weld bead geometrical parameters that determine its mechanical properties. The proficient use of any welding method relies upon the comprehension of related parameters that impact the weld quality. The weld quality incorporates the size of the weld bead, mechanical properties, distribution of temperature and micro structural changes. Heat transfer effect on characteristics of weld bead during SAW process and mathematical modeling is developed through central composite design technique of response surface methodology. The scatter and contour plots are plotted on mean value and they have good compatibility with the predicted values.

The Corrosion Process of an API 5L X80 Welded Joint in a System with Different pH and H2S Concentration

The corrosion evaluation of steels in the oil and gas industry environments is a crucial issue because corrosion can cause economic and human losses. It is well known that H2S can be originated from different processes in the oil and gas industry, accelerating the corrosion process. The objective of this work was to evaluate the H2S corrosion resistance of an API 5L X80 steel and its welded joint obtained by submerged arc welding process (SAW). All tests were performed in an aerated 5% wt NaCl and thiosulphate aqueous solution. The H2S concentration, pH, weight loss, electrochemical tests, and microstructure were considered. The results obtained showed an increase of the corrosion rate values, with decreasing pH and increasing concentration of H2S generated by the thiosulphate. For the lowest H2S concentrations, the corrosion process was inhibited, due to the formation of a partially protective film on the samples’ surfaces. The heat affected zone (HAZ) showed severe localized corrosion attack which was attributed to the microstructural characteristics of this region.

Effect of Submerged Arc Welding Process on Hardness and impact Properties of Fabricated SAE1020 Low carbon Steel Plates.

Effect of Submerged Arc Welding Process on Hardness and impact Properties of Fabricated SAE1020 Low carbon Steel Plates.

Effect of Boehmite Nanoparticles Surface Adsorbed with Vanadium on the Microstructure and Hardness of the Melted Zone in the Submerged Arc Welding Process

One of the most important weld quality characteristics related to the strength of the weld is the hardness of melted zone (HMZ) that is affected by different input parameters in the submerged arc welding process. In recent years, expensive nanomaterials have been effectively used in improving the quality of products in various fields. Keeping this in mind, it was therefore, decided to use a cost-effective approach to extract expensive and poisonous vanadium, from the hazardous wastewater collected from the Bistoon thermal power plant in Kermanshah province in Iran, and then introduce it into the weld pool via the cheap boehmite nanoparticles to investigate its impact on the HMZ. A five-level five-factor rotatable central composite design was then employed for collecting data in modeling of the HMZ as a function of arc voltage (V), welding current (I), stick-out (N), welding speed (S), and thickness of boehmite nanoparticles surface adsorbed with vanadium (F) coated on low-carbon steel plates (St37) prior to actual welding. The results showed that the addition of boehmite nanoparticles surface adsorbed with vanadium increased the HMZ by 13 % approximately.

Microstructure and corrosion characterization of weld metal in stainless steel and low carbon steel joint under different heat input

In this study, a novel method of the arc assisted tungsten insert gas (AA-TIG) backing welding and the submerged arc welding (SAW) to fill the groove was used to join 12Cr2Mo1R low carbon steel and S30408 stainless steel. The weld metal microstructure characteristics of different heat input and its microhardness and corrosion resistance were investigated in detail. The optical microscope (OM) and scanning electron microscope (SEM) was used to analyze the microstructure and composition distribution of weld zone. The cyclic potentiodynamic polarization and electrochemical impedance spectroscopy were employed to determine corrosion resistance of weld zone under different heat input. The results show that the combination welding process of AA-TIG backing welding and SAW can effectively join thick plate with high efficiency, and the weld shape is good without incomplete fusion and penetration. A higher ratio between ferrite and austenite under higher heat input, resulting in finer microstructure with increased hardness. Further, discovered by discussing the corrosion mechanism is due to the high content of Ni and C elements in the weld are likely to form Ni-C phase, which become the inducing point of pitting corrosion. It is recommended to use a higher heat input to obtain the best corrosion resistance of the welded area.

Analyzing the response of submerged arc welding process parameters on Form factor and dilution

Stainless steel (316) possesses higher strength to weight ratio, high toughness and high tensile strength. It has wide range of applications in fabrication of heat exchangers, boat fittings as wire rope clips, in making of tanks, springs and screws, Medical implants, Sinks and splash backs. Welding of these materials has always been a challenging task. Submerged arc welding due to its various properties and specification has been found suitable for this type of work. In this research work, weld bead geometry parameters; Dilution, Form Factor were optimized by using Response Surface Methodology (RSM). Welding current has been found to be the most crucial parameter among all the selected parameters.

Research regarding strip cladding of heat-resistant SA 387 Gr.11Cl.2 steel type

The continuous development of industrial processes in the petrochemical field requires the use of materials with anticorrosive properties, able to withstand working conditions at high temperatures but also in highly corrosive environments. The basic materials with anticorrosive properties have a high cost price which leads to the need to find alternative manufacturing solutions. In such situations, the use of bimetal plates or the option of welding cladding with an anticorrosive layer of the base material is used. The paper analyses the possibility of strip cladding using the submerged arc welding process of a reactor made of SA 387Gr11Cl.2 basic material, a heat-resistant alloy steel. To achieve the deposition of the appropriate anticorrosive layer (stainless steel type AISI 347) it was necessary to use a buffer layer made of austenitic stainless-steel type 309L. In order to eliminate the internal tensions appeared after the cladding process, the sample was subjected to a stress relieving heat treatment. After the heat treatment, the sample was subjected to non-destructive examinations (visual and penetrant testing) but also to destructive examinations specific to the approval tests of cladding technology (Metallographic tests, Vickers hardness test, bend test, ferrite number, chemical composition). Metallographic tests of cross-sectional phase structures were carried out in macroscopic and microscopic terms. In the area of the deposited material can be observed a typical austenitic casting structure resulting from the use of a high linear energy, specific to the automatic submerged arc welding. Following the performance of hardness measurements made in the characteristic areas of the deposition, it can be seen that there was a slight increase in the values obtained in the heat affected zone, without exceeding the prescribed values for the materials used. Following the analysis of the results obtained from the specific examinations and tests to the plated samples, it can be seen that they are within the limits prescribed by the standards in force regarding the approval of the cladding technology used.

Investigations on Wear Behaviour of AISI 4140 Hot Strip Mill Roller Hardfaced with Martensitic Stainless Steel by Submerged Arc Welding Process

Investigations on Wear Behaviour of AISI 4140 Hot Strip Mill Roller Hardfaced with Martensitic Stainless Steel by Submerged Arc Welding Process

Ensemble of convolutional neural networks based on an evolutionary algorithm applied to an industrial welding process

This paper presents an approach for image classification based on an ensemble of convolutional neural networks and the application to a real case study of an industrial welding process. The ensemble consists of five convolutional neural networks, whose outputs are combined through a voting policy. In order to select appropriate network parameters (i.e., the number of convolutional layers and layers hyperparameters) and voting policy, an efficient search process was carried out by using an evolutionary algorithm. The proposed method is applied and validated in a case study focused on detecting misalignment of metal sheets to be joined through submerged arc welding process. After selecting the most convenient setup, the ensemble outperforms other seven strategies considered in a comparison in several metrics, while maintaining an adequate computational cost.

Welding of Large Thickness Super Duplex Stainless Steel: Microstructure and Properties

In this study, Submerged Arc Welding (SAW) and Gas Metal Arc Welding (GMAW) processes were used in multi-pass welding of 33 mm thickness super duplex stainless steel plates. Recommended and higher than recommended arc energy and interpass temperatures were used. Both GMAW and SAW processes were able to produce large thickness weldments meeting the microstructural, mechanical, and corrosion resistance requirements, and also when using higher than recommended arc energy and interpass temperature. It was possible to reduce the number of welding passes by half when using higher than recommended arc energy and interpass temperature. The SAW process needed only half of the welding time required for the GMAW process to produce a weldment with nearly the same number of weld passes, when using recommended arc energy and interpass temperature. Based on the results of this investigation, the practical recommendations for welding large thicknesses should be revised and updated.

Effect of filler wire preheating and nozzle cooling with advanced submerged arc welding process on bead geometry and microstructure

ABSTRACT Submerged arc welding is an extensively used technique as it provides good weld quality and high deposition rate. Therefore, to obtain these results it is very crucial to optimised welding parameters. In this present work bead on plate experiment are performed on AISI 1023 steel by submerged arc welding (SAW) and then on advance submerged arc welding (ASAW) to analyse and optimised the various welding input parameters like voltage, preheat current, wire feed rate, nozzle to plate distance, welding speed through weld bead geometry. After the experiments, responses are analysed by trends, microstructure and also by using hybrid Analytic hierarchy process (AHP) – Technique of Order Preference Similarity to the Ideal Solution (TOPSIS) process. It shows that open circuit voltage of 44 V and preheat current of 200 Amp is most suited for the various application.

Internal stresses in a clad pressure vessel steel during post weld heat treatment and their relevance to underclad cracking

A potential connection between the residual stresses generated by a cladding operation, the thermal stresses generated during post weld heat treatment (PWHT), and the propensity for underclad cracking was investigated. As-deposited residual stresses were measured at ambient temperature, using the contour method and neutron diffraction. Measurements were performed in 20mm thick steel substrates that were partially clad with AISI grade 309 (layer 1) and grade 308 (layer 2) stainless steels, using the submerged-arc welding process. Neutron diffraction measurements were also performed after heating the clad samples to 200 and 325°C. The mechanical properties in each region within the steel heat affected zone (HAZ) were determined, at those same temperatures, by subjecting coupons to simulated cladding thermal cycles and then to tension tests. Substantial tensile residual stresses in the HAZ were measured after cladding. These persisted during subsequent heating to 325°C: a temperature that is approximately at the mid-point of the heating ramp in a typical PWHT cycle. The tensile results, however, indicated that each microstructural zone within the HAZ is likely to retain sufficient ductility to prevent fracture, and that underclad cracking is unlikely to occur during the early stages of the PWHT ramp.

Using Artificial Neural Networks to Predict the Effect of Input Parameters on Weld Bead Geometry for SAW Process

Based on high quality and reliability, one of the most efficient methods for joining metals is Submerged Arc Welding (SAW). In this presented work, an attempt has been successfully taken to develop a model to predict the effect of input parameters on weld bead geometry of submerged arc welding process with the help of neural network technique and analysis of various process control variables and important of weld bead parameters in submerged arc welding. The complexity non-linear relationships of input / output variables for any computational models can be addressed by using artificial neural networks (ANN). Today, ANN represents a powerful modeling technique, that depend on statistical approach, presently practiced in many fields of engineering for modeling complex relationships that other physical models cannot be explained it easily. A welding process with automatic or semiautomatic is required to complete the weld through using tubular electrode with consumable flux. Parameters such as welding current, welding speed and voltage are influenced on the quality of the joints. The work conducts many experiments; these are basically depending on many factors and levels. A selection of 2205 duplex stainless steel is carried out in this study to conduct three factors and five levels of central composite design. Neural network model structure having number of neurons layers such as (3 input layers, 1 hidden layer and 3 output layers) with back propagation algorithm has been successfully applied to extract weld bead geometry from predicting the effect of input parameters. Good agreement was obtained between predicted and experiment results, however process parameters such as speed shows opposite effect on all weld parameters. It was seen that weld height and width are proportional to the amount of input current. The prediction of the neural network model showed excellent agreement with the actual results, which indicate that the neural network is viable means for predicting of not only weld bead geometry, but also other parameters such as polarity, current type and flux geometry. This recommends setting the neural network to be applicable for real time work.

Establishing empirical relationship between welding current and weld metal deposition rate for submerged arc welding process

Any increase in the productivity of the SAW process will immensely benefit the welding industry, as this process is widely used. Since the traditional single wire DCEP SAW system is extensively used even today, any enhancement using this system will benefit the industry in a big way, if this traditional SAW system is part of the improvisation process. This paper establishes a relationship between welding current and productivity (deposition rate), for the three common sizes of both solid wires and metal cored tubular wires at different current values over its full range, through bead-on-plate experimentation. At each preset current value, the weld bead was optimized for acceptable visual quality, by adjusting arc travel speed and voltage, then the wire feed rate-making optimized bead was noted. The weld metal deposition rate was calculated for establishing A vs WMDR empirical relationships. From the results, ten progressive strategies have been established which can improve welding productivity from 21 to 211% from baseline. The established relationships, strategies can be effectively used, to estimate/optimize the productivity based on the welding current values, for each wire type and diameter.

Recycling of steel slag as a flux for submerged arc welding and its effects on chemistry and performance of welds

The slag generated by the steel plant has been utilized to produce submerged arc welding flux. The flux produced by recycling steel slag has been applied in the submerged arc welding process. The effects of recycled slag on the chemical composition, microhardness, and microstructure of weld metal have been evaluated. For chemical composition, weld pads were prepared and beads on plates for bead geometry were deposited. It has been found that the chemistry of welds deposited using recycled steel slag is acceptable in accordance with ASME specifications. It is further observed that the addition of 10% CaCO3, 20% SiO2, and 6% MnO to the steel slag during recycling provided 0.10% carbon, 0.11% Si, and 0.8% Mn, respectively, in the weld metal. The microstructure of welds produced using recycled steel slag contains acicular ferrite which is desirable for improved tensile and impact strength. The microhardness of weld metal prepared using recycled steel slag is 220.9 VHN, which is more than that of weld metal deposited with fresh flux. Smooth surface appearance and desirable bead profile having deeper penetration were obtained. It is interesting to note that the cost of recycled steel slag is economical by 62% in comparison with equivalent virgin flux available in the market. The developed technology after fine-tuning will be transferred to the industry for practical applications.