Welding Procedure Specification Research Articles

Kalibrasi Wire Feeder Flux Core Arc Welding (FCAW) Mengacu Pada Standar British Standard (BS) 7570:2000 Dan British Standard (BS) European Standard (EN) 50504:2008

In the fabrication industry, the welding process plays a crucial role in both engineering and repair production processes. Continuous use of welding machines can lead to a decline in their effectiveness. Suboptimal machines may produce low-quality products. A common issue encountered is the poor quality of welds, even when each step has been aligned with the Welding Procedure Specification (WPS). One source of this problem is the welding equipment itself. The objective of this study is to calibrate arc welding equipment to ensure it remains within machine standards. Calibration is performed in accordance with BS EN 50504:2008 and BS 7570:2000. The calibration focuses on measuring constant voltage and wire feed speed (WFS). The measurement results for WFS variation indicate that it does not exceed a 10% error margin. This suggests that the WFS complies with the established standards. Consequently, the Lincoln LN-25X wire feeder speed is ready for use in fabrication and production processes.

Assessment of Mechanical Strength of A36 Steel with Flux Cored Arc Welding Process

Shielded Metal Arc Welding (SMAW) is a popular welding technology in the construction and industrial sectors due to its ease of use. Flux-cored arc welding (FCAW) has gained popularity in the construction sector and industrial settings. The Welding Procedure Specification (WPS) restricts material compatibility for FCAW due to systematic selection and qualification. Penetrant Testing exposes damage to welded specimens, ensuring they meet the standard. Non-Destructive Testing (NDT) and mechanical tests like tensile and bending tests determine the mechanical strength and weld characteristics of steel using FCAW. The results show the effectiveness of pWPS and satisfy the code and standard. Dye Penetrant Test results show no cracks and acceptable criteria for both side A and side B of the steel plate. Bending test results show expected yield points, but failures occur due to discontinuities in break force and failures in tensile strength.

Reviewing Welding Procedures—Checklists for Nuclear Power Systems

Abstract To ensure effective control of the welding process, nuclear power architecture and engineering (AE) companies routinely undertake the review of procedure qualification records (PQRs) and welding procedure specifications (WPSs) for safety-related structures, systems, and components (SSCs), as qualified by manufacturers and construction contractors. Given the substantial quantity of PQRs and WPSs necessitating evaluation, along with the multitude of variables inherent in these documents, a set of review checklists has been devised. These checklists, developed from the perspective of AE companies' welding engineers, transform welding procedure qualification rules and requirements into intuitive descriptions, assessments of correctness, or numerical comparisons of scale. AE companies' welding engineers employ these review checklists to scrutinize PQRs and WPSs, facilitating a comprehensive, accurate, and efficient review process.

Analysis of Electric Current on Aluminum Plate Welding Using MMA (Manual Metal Arc) Method

Many industries depend on welding, which joins materials with heat. This research focuses on Manual Metal Arc (MMA) welding aluminum plates due to its adaptability for thin materials and compatibility with aluminum's unique properties. The study investigates how electric current affects aluminum plate MMA welding, improving welding methods. The study examined the effect of electric current on aluminum plates using the MMA method using a qualitative descriptive research design. Sorong Merchant Marine Polytechnic's workshop laboratory conducted the research from February to May 2023 using AWS E 6013 welding electrodes and ASTM A36 plates. Data was collected through observation, documentation, and literature review, then analyzed using data reduction principles. Results show that electric current variation significantly affects welding characteristics. Increased amperage penetrates deeper, but excessive current can melt and weaken joints. Amperage, weld rate, joint quality, and penetration depth must be balanced. The study emphasizes precise welding control, improving welding efficacy. The complex relationship between critical parameters emphasizes the need for careful equilibrium and the importance of following welding guidelines and parameters in the Welding Procedure Specification. As inadequate or excessive current can affect weld quality, this research improves MMA aluminum plate welding results.

Reinforcement learning as data-driven optimization technique for GMAW process

Welding optimization is a significant task that contributes to enhancing the final welding quality. However, the selection of an optimal combination of various process parameters poses different challenges. The welding geometry and quality are influenced differently by several process parameters, with some exhibiting opposite effects. Consequently, multiple experiments are typically required to obtain an optimal welding procedure specification (WPS), resulting in the waste of material and costs. To address this challenge, we developed a machine learning model that correlates the process parameters with the final bead geometry, utilizing experimental data. Additionally, we employed a reinforcement learning algorithm, namely stochastic policy optimization (SPO), with the aim to solve different optimization tasks. The first task is a setpoint‐based optimization problem that aims to find the process parameters that minimize the amount of deposited material while achieving the desired minimum level of penetration depth. The second task is an optimization problem without setpoint in which the agent aims to maximize the penetration depth and reduce the bead area. The proposed artificial intelligence-based method offers a viable means of reducing the number of experiments necessary to develop a WPS, consequently reducing costs and emissions. Notably, the proposed approach achieves better results with respect to other state-of-art metaheuristic data-driven optimization methods such as genetic algorithm. In particular, the setpoint‐based optimization problem is solved in 8 min and with a final mean percentage absolute error (MPAE) of 2.48% with respect to the 42 min and the final 3.42% of the genetic algorithm. The second optimization problem is also solved in less time, 30 s with respect to 6 min of GA, with a higher final reward of 5.8 from the proposed SPO algorithm with respect to the 3.6 obtained from GA.

A review towards Friction Stir Welding technique: working principle and process parameters

Friction Stir Welding (FSW) is a solid-state bonding process that employes tools that are not used up and can function to connect two opposite workpieces without melting the workpiece material. The friction force has been micro-structurally tested to reformat or transform the inner state of the structure properties (atomic formation) form in metal since the kinetic energy of friction has been utilised in one of the welding techniques. Right afterwards, the studies reported that the mechanical properties also underwent a significant deformation. The aim is to determine the effect of Welding Procedure Specification (WPS) product quality. As it develops through research and applied experiments, the branch of friction-based welding discipline can be classified depending on how the friction mechanism can produce the finest solid-state joint, which is suitable to the typical property of metal and can be maximised by joint configuration. Friction Stir Welding is a friction-based welding technique that uses the stirring tool to generate friction while the workpieces are stuck on the line of the FSW joint configuration. The relevant correlations amongst process parameters and inside its respective adjustable variables are constructed to the finest principles that produced top-grades empirical reports of the weld properties. In this review, the explanation of the working principle and clarification of process parameters are presented. The cited references are selected from creditable and verifiable articles and books in the last ten years. Expectedly, it will be able to pioneer a new face of simple and understandable review articles.

Certification of welder for tungsten inert gas welding in unmanned aerial vehicle systems

Aluminum and its alloys is one of the extensively used non-ferrous metal in aerospace engineering applications due to its excellent properties like higher strength to weight ratio, non-magnetic property, high thermal conductivity, good machinability, recyclability, and excellent formability. However, welding of aluminum and its alloys has always been a challenge due to drastic reduction in strength near heat affected zone (HAZ). Due to softness, ductility, lower melting point of aluminum and its alloys impose additional challenges to weld aluminum alloy components. Due to this, the quality and quantum of skill set needed to weld aluminum alloy joints for flight critical components is much more than that of welding of ferrous materials. The qualification and certification of welder is one of the prime requirements in welding applications especially in aerospace industry. This paper mainly discusses the various aspects involved in qualifying and certifying a welder for tungsten inert gas (TIG) welding process of aluminum alloys, which is treated as one of the special processes. The welder certification is a written verification that weld joints produced by welder meets the prescribed standard of welder performance. It is to verify the ability of an individual to execute a qualified welding procedure specification to produce a sound weld. Aluminum alloy 6xxx series is considered for base metal for sample preparation and weld joint assessment studies, as it is one of the prevalently used aluminum alloy material in unmanned aerial vehicle (UAV) applications. Weld samples are prepared as per internationally practiced standards and welding procedure specification (WPS) is recorded. Various mechanical tests carried out on weld samples during certification process are discussed in the paper. Weld joints are subjected to tensile testing, bending test and macro test. The certifying agencies are involved at every stage to ensure consistency of welder performance.

Supervised recommendations of gas metal arc welding parameters

In gas metal arc welding, a weld quality and performance depends on many parameters. Selecting the right ones can be complex, even for an expert. One generally proceeds through trial and error to find a good set of parameters. Therefore, the current experts’ method is not optimized and can require a lot of time and materials. We propose using supervised learning techniques to help experts in their decision-making. To that extent, a two-part recommendation system is proposed. The first step is dedicated to identify, through classification, the number of weld passes. The second one suggests the seven remaining parameter values for each pass: layer, amperage, voltage, wire feed rate, frequency offset, trimming and welding speed. After extracting data from historical Welding Procedure Specification forms, we tested 11 different supervised learning algorithms. The recommendation system is able to provide good results for all the different settings mentioned above even if the data is noisy due to the heuristic nature of the experts’ process. The best classification model is CatBoost with 82.22% average F1 Weighted-Score and the best regression models are Extra Trees or a boosting algorithm with a reduced mean absolute percentage error compared to our baseline.

Analysis of the Effect of Electrode Variation and Current on the Welding Results of Corten A Steel using SMAW Method on Microstructure, Corrosion Resistance, and Mechanical Properties

The emission exhaust stack in industries must have good corrosion resistance and heat resistance in both the base metal and the welded joints. Therefore, corten steel is chosen as the base metal for the exhaust stack due to its excellent corrosion resistance and heat resistance, as well as its costeffectiveness compared to other heat-resistant steels. This study aims to analyze the welded joints of corten steel in terms of microstructure, corrosion resistance, and tensile strength using the Shielded Metal Arc Welding (SMAW) method, following the Welding Procedure Specification (WPS). The variables used in this study are the electrode variations using E7016-G and E8016-G electrodes, and the current variations of 90, 105, and 120 A. The results of this study indicate that in the metallography testing, the highest percentage of the perlitic phase is found in specimen B2, which uses the E8016-G electrode and a current of 105A, reaching 41.92% in the weld metal and 29.6% in the Heat-Affected Zone (HAZ). In the corrosion resistance testing, the corrosion rate fluctuates within the 3-hour and 6-hour time ranges, but decreases within the 10-hour time range. The lowest corrosion rate is observed in specimen B2 using the E8016-G electrode and a current of 105A. In terms of mechanical properties, the best results are obtained from the tensile testing and hardness testing of specimen B2 using the E8016-G electrode and a current of 105A.

Tensile test analysis for steel welding connections as a basis for compiling welding procedure specification (WPS)

Welding is the train manufacturing industry's most widely used method of joining metal plates. The welding method and the qualification of the weld results can be ascertained using the WPS document. The construction of WPS begins with setting up standards that will obtain the most appropriate welding procedures, then determining the type of material strength test to ensure the quality of the welds. This research was conducted to determine whether the S355 J2 steel can withstand the stress of the load before it is deformed by the welding procedure that has been determined. Tensile tests were carried out on welded S355 J2 steel. The tensile test results obtained a higher value than the standard material that is not welded. Therefore, it can be ensured that the welding procedure used is correct. This is caused by several factors, including the type of welding according to the material, the use of the type of electrode, the making of the joint design, and the correct welding parameters.

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.

Analysis of Welding Procedure Specifications for steel line pipe material

This study proposes the welding process steel line pipe material of API5L Grade X52 diameter Ø8 inch SCH80 type, subjected to the good quality of the product by following the Welding Procedure Specifications (WPS). The purpose of welding using WPS is to ensure that the welding process follows the correct stages because the steps are proper. The weld results will be free from defects and safe for line pipes. In order to confirm the WPS quality, the characterisations of macrostructure, microstructure, and mechanical properties were analysed. The welding process results by following the procedure specifications, from macrostructure shown no porosity, and sample without following the welding procedure specifications shown porosity at weld metal position. The tensile test sample following the welding procedure specifications showed high strength and ductility compared with the samples without welding procedure specifications. This phenomenon occurs due to the grain size of the martensitic structure and a little bit of growth compared with a sample without following the welding procedure specifications. Furthermore, the bending test result shows that both samples have no crack at the weld metal position.

Experimental investigation of residual stress distribution on girth welds fabricated at proximity using neutron diffraction technique

Maintaining minimum distance between repair and existing welds often becomes impractical due to the presence of compact layouts, original welds of branches, nozzles, etc. on offshore structural elements, pipelines, and piping. Although some international codes and standards provide criteria for maintaining a minimum distance between proximity welds, most of them lack technical justification in relation to their effect on the structural integrity of welded components. The development of residual stresses has a significant effect (i.e., a negative effect on tensile stresses and a positive effect on compressive stresses) on the integrity of the welds fabricated at proximity. Hence, it is important to investigate the residual stress distribution on welds fabricated at proximity, especially at a distance away from the weld toe. This study presents findings on the characterization of residual stresses by neutron diffraction at the proximity region between two girth welds. The two welds were fabricated at proximity, using two different welding procedure specifications and at three different distances, on a structural steel pipe, grade S355. The three different welding distances between weld toes were maintained at 5, 10, and 15 mm respectively. The neutron diffraction-based residual stress distributions were investigated at the POLDI neutron instrument at the Swiss spallation source SINQ in Switzerland. The axial, hoop, and radial components of the residual stresses were experimentally investigated between proximity welds. The findings revealed that residual axial stresses at a 5-mm proximity distance were increased beyond the yield strength of the structural steel, grade S355. The findings of this study enable practitioners to take remedial actions to minimize the residual stresses developed in girth welds fabricated at proximity. Also, the findings enable us to derive technical justification for maintaining a minimum distance and developing welding procedure for welds fabricated at proximity.

Deep Neural Networks for Defects Detection in Gas Metal Arc Welding

Welding is one of the most complex industrial processes because it is challenging to model, control, and inspect. In particular, the quality inspection process is critical because it is a complex and time-consuming activity. This research aims to propose a system of online inspection of the quality of the welded items with gas metal arc welding (GMAW) technology through the use of neural networks to speed up the inspection process. In particular, following experimental tests, the deviations of the welding parameters—such as current, voltage, and welding speed—from the Welding Procedure Specification was used to train a fully connected deep neural network, once labels have been obtained for each weld seam of a multi-pass welding procedure through non-destructive testing, which made it possible to find a correspondence between welding defects (e.g., porosity, lack of penetrations, etc.) and process parameters. The final results have shown an accuracy greater than 93% in defects classification and an inference time of less than 150 ms, which allow us to use this method for real-time purposes. Furthermore in this work networks were trained to reach a smaller false positive rate for the classification task on test data, to reduce the presence of faulty parts among non-defective parts.

Multi-Objective Optimization of MIG Welding and Preheat Parameters for 6061-T6 Al Alloy T-Joints Using Artificial Neural Networks Based on FEM

To control the welding residual stress and deformation of metal inert gas (MIG) welding, the influence of welding process parameters and preheat parameters (welding speed, heat input, preheat temperature, and preheat area) is discussed, and a prediction model is established to select the optimal combination of process parameters. Thermomechanical numerical analysis was performed to obtain the residual welding deformation and stress according to a 100 × 150 × 50 × 4 mm aluminum alloy 6061-T6 T-joint. Owing to the complexity of the welding process, an optimal Latin hypercube sampling (OLHS) method was adopted for sampling with uniformity and stratification. Analysis of variance (ANOVA) was used to find the influence degree of welding speed (7.5–9 mm/s), heat input (1500–1700 W), preheat temperature (80–125 °C), and preheat area (12–36 mm). The range of research parameters are according to the material, welding method, thickness of the welding plate, and welding procedure specification. Artificial neural network (ANN) and multi-objective particle swarm optimization (MOPSO) was combined to find the effective parameters to minimize welding deformation and stress. The results showed that preheat temperature and welding speed had the greatest effect on the minimization of welding residual deformation and stress, followed by the preheat area, respectively. The Pareto front was obtained by using the MOPSO algorithm with ε-dominance. The welding residual deformation and stress are the minimum at the same time, when the welding parameters are selected as preheating temperature 85 °C and preheating area 12 mm, welding speed is 8.8 mm/s and heat input is 1535 W, respectively. The optimization results were validated by the finite element (FE) method. The error between the FE results and the Pareto optimal compromise solutions is less than 12.5%. The optimum solutions in the Pareto front can be chosen by designers according to actual demand.

Prediction and mitigation of out-of-plane welding distortion of a typical block in fabrication of a semi-submersible lifting and disassembly platform

Out-of-plane welding distortions of block structures during fabrication of offshore structure will significantly influence its dimensional accuracy and production schedule. Taking a B514 block of a semi-submersible lifting and disassembly platform as research object, typical welded joints and their welding conditions were summarized based on actual welding procedure specification (WPS). Effective thermal elastic plastic (TEP) finite element (FE) analysis with parallel computation technology was carried out to examine thermal-mechanical response. Welding inherent deformations, which are considered as the elementary cause of welding distortion, were then evaluated. With welding inherent deformations as mechanical loading, elastic finite element (FE) analysis was then employed to predict dimensional accuracy of examined B514 block, which has a good agreement with measurement data. In order to ensure the fabrication accuracy with less out-of-plane welding distortion, inverse deformation approach was applied to reduce the out-of-plane welding distortion, and influence of welding sequence on out-of-plane welding distortion was also examined. Both mitigation practices have obvious effect on dimensional accuracy of examined B514 block, while corresponding mechanical mechanisms were also clarified.

Fabrication technologies implemented for the European test blanket modules: Status for HCPB and WCLL

Abstract Within the framework of the European fusion strategy, two tritium Breeder Blankets concepts are developed to be tested in ITER as Test Blanket Modules (TBM): the Water-Cooled Lithium-Lead (WCLL) which uses the liquid Pb-16Li as a breeder, neutron multiplier and tritium carrier, and the Helium-Cooled Pebble-Bed (HCPB) with lithiated ceramic and beryllium pebbles as breeder and neutron multiplier, respectively, and helium purge gas as tritium carrier. Both concepts consider as structural material reduced activation ferritic martensitic steel, the EUROFER97 (X10CrWVTa9-1). Pressurized water (15.5 MPa, 295−328 °C for WCLL) and pressurized helium (8 MPa, 300−500 °C for HCPB) are foreseen for heat removal. The TBM is constituted of a BOX (side caps, first wall), stiffened by stiffening plates (SP) and closed on its back, in the manifold area, with back plates with passing-through elements, like stiffening/tie rods, SP nozzles and inlet/outlet water/He pipes. Internally, breeder units, delimited by SP, are cooled-down by cooling plates for the HCPB and double-wall tubes for the WCLL. This paper describes manufacturing technologies for the TBM and deals with the definition of the preliminary Welding Procedure Specifications (pWPS) and feasibility mock-ups for the manifold area and TBM BOX assembly. The transfer and validation of the pWPS developed for the TBM, from P91 to EUROFER97 steel, is demonstrated. Consolidation of the pWPS for the TBM BOX assembly made with HIP process and development for the HCPB TBM manifold area elements, based on GTAW technique, are discussed. Manufacturing tests are performed using the EUROFER97 steel (RCC-MRx, AFCEN Code rules [ 1 ]). As part of the WCLL conceptual design development activities, an assembly and manufacturing welding sequence is detailed, focusing on design changes and the impact on the selection of manufacturing technologies. The article will present as well the future fabrication developments and the associated design proposals envisaged on TBM.

Development and application of knowledge-based software for railcar frame welding process

As main welded components of the rail vehicle, the railcar frames have specific needs in preparing a suitable welding document for each welded joint to guide the welding process during the manufacturing process. In this paper, the expert system and database technology are introduced into the field of rail vehicle welding process preparation, and a knowledge-based software for railcar frame welding process is developed. This system could maintain the normal operation of the enterprise rail welding system based on knowledge base and database. The numerous paper-based and fragmented electronic documents are stored in a unified format within the system’s database, and a reasoning mechanism based on Rule-Based Reasoning (RBR) and Case-Based Reasoning (CBR) is designed to intelligently match the welding procedure specification (WPS) and welding procedure qualification report (WPQR) online. Furthermore, the system supports multiple departments and personnel by integrating the function of workflow to carry out the WPS prepare and review process. Thousands of welded joints with various structures and complex positions in the same vehicle body can be aggregated into a welding summary table to reduce the repeated welding procedure qualifications (WPQ) of the same or similar welding joint. This method not only saves manpower and resources, but also ensures the accuracy of these process documents. In the end, the future development trend of this kind of application software is prospected.

Bed Frame Fabrication for Heavy Duty Machine Tools or Unique of High Strenght Materials Quend 700

The purpose of the present work is to present new manufacturing technologies process of bed frame elements, especially those with a circular or conical section, made of high strength materials, new on the market. The research based on three methods to make this bed frame elements: cold deformation method, hot deformation method and cold deformation method after soft annealing. Experimental research is focused on how the steel behaves at high temperatures, in identifying an adequate improvement treatment for parts after soft annealing, to increase the mechanical properties of this and preparation of the welding procedure specification.

ANALISIS STANDARISASI PROSES PENGELASAN GMAW TERHADAP PENGELASAN BEJANA TEKAN JENIS SILO ASME

Pressure vessel is a container for a fluid, both liquid fluid and pressurized gas. In designing a pressure vessel, there are several things that must be considered, namely the stress that appears on the vessel wall due to the pressure caused by the fluid in the vessel, the weight of the vessel itself, or due to pressure arising from external factors. The process of making pressure vessels is carried out using the rolling process and the assembly welding process. The welding process must be considered based on the level of density, leakage and at the same strength. Planning the welding procedure to be carried out on the pressure vessel, the first welding process carried out is Head, Shell 1 body, Shell 2 Body, Shell 3 cone, Shell 4 cone, and Bottom Plate. The material to be used is SA 516 GR 70 according to ASME (American Society of Mechanical Engineers) section II D. Welding process using GMAW (Gas Metal Arc Welding), welding connection planning, welding parameters and everything related to the welding process is determined and summarized on WPS (Welding Procedure Specification) based on ASME (American Society of Mechanical Engineers) section IX. Testing on the welding results is carried out in several stages starting from the penetrant test, radiography test, peneumatic test, and hydrostatic test. The test is carried out to determine the quality of the welding results. Then an analysis of the results of the welding that has been tested is carried out to really know the quality of the standardization used. Based on the results of several stages of testing on the GMAW (Gas Metal Arc Welding) welding process with the standardization used, there are still defects in the welding results.