Industrial Welding Research Articles

Improvement Research on Quality Management Systems and Executive Ability Effect in the Chinese Welding Industry

Nowadays executive ability improvement research is fundamental in the Chinese welding industry for large-scale, state-owned, and joint-venture companies. It is important that the quality, cost, and productivity of their products are tightly linked with executive ability. The lack of executive ability in large-scale factories or a welding quality management system in middle and small-scale factories is a widely existing problem. The lack of powerful and appropriate executive ability means not only no increases in the quality and productivity, but also no decreases in the manufacturing cost. On the other hand, for small and middle-scale factories, a welding quality management system is important. These two topics, executive ability and the quality management system, are the most significant and urgent issues to the Chinese welding industry. The paper presents the current situation of the relationship of the quality management system and executive ability of companies and factories in the Chinese welding industry in different geographical areas. The paper first analyzes the existing research circumstance and finally provides countermeasures and suggestions to the Chinese welding companies. As a result, this paper presents proposals to increase the executive ability and also a way to build a welding quality management system. They can be implemented in different scale welding enterprises also for other new industrial countries.

Occupational Exposure and Health Problems of Workers in Unauthorised Small-Scale Welding Industries in Delhi: A Situational Analysis

Occupational Exposure and Health Problems of Workers in Unauthorised Small-Scale Welding Industries in Delhi: A Situational Analysis

Investigation of Cold Pressure Welding: Cohesion Coefficient of Copper

Joining materials by forming is an interesting approach to the manufacture of hybrid (multi material) parts. By establishing a cold pressure weld between metallic surfaces, high quality joints with superior properties can be achieved. Reliable cold welding conditions are difficult to set up, however, since the weld initiation requires extraordinary clean, virtually sheer surfaces. Until today such conditions could only be achieved under a high vacuum conditions. Various studies on cold pressure welding reported that under vacuum welds can be established at significantly lower deformation than in a normal atmosphere. Since adverse deformation is currently needed in industrial cold pressure welding processes like the cold roll cladding of metal bands, a new process with in-line electrochemical surface treatment, is investigated. The ECUF process is intended to supply clean and thereby highly activated surfaces to the cold pressure welding process.This paper presents first results on the weld-ability of copper specimens with regard to the influence of the welding environment: air, argon and KCl solution. Butt welds were made by pressure welding of previously fractured specimens.

Study on the wire feed speed prediction of double-wire-pulsed MIG welding based on support vector machine regression

Obtaining the wire feed speed which can properly match the process parameters is difficult in double-wire-pulsed metal inert gas (MIG) welding. This work analyzed ten factors which affect the wire feed speed in reality and conducted corresponding correlation analysis. Then, four significant correlation factors, which were duty ratio, frequency, average current of leading wire, and average current of trailing wire, are selected as independent variables for establishing a double-wire feed speed prediction model. The model established by support vector machine regression used two evaluation criterions, which were the mean square error (MSE) and squared correlation coefficient (SCC), and then obtained the optimal model parameters by mesh optimization. Finally, the proposed model was validated by actual double-wire-pulsed welding experiments. This study can optimize the double-wire welding technological designing process and improve the intelligent double-wire welding industry.

Weld Quality Assurance Practices in the Metal Welding Industries in Ghana

This study investigates the weld quality assurance practices in the metal welding industries in Ghana. The data for the study were collected using questionnaire, interview and personal discussions. One hundred and twenty informal sector welders, 80 formal sector welders, and 25 welding hardware shops/dealers were contained in the analyzed sample. The results of the analysis revealed that majority of the welding industries in the country lack weld quality assurance standards, weld quality testing equipments and materials as well as personnel to help assure weld quality practices in the metal welding industries. Also, equipments and materials for welding inspection and testing are not readily available in the welding hardware shops in the country. Moreover, even though most of the welders in the country have considerable years of working experience, they lack the skills of ensuring quality in their welding activities due to low levels of technical training. To instill professionalism into the welding industry, the suppliers should import the weld quality testing equipments into the country to be made available to the welders. The welders and the suppliers should take advantage of training programs offered by the training institutions in the country to enable them upgrade and update their knowledge and skills in weld quality assurance practices. The Government, the banks and other corporate organizations should help establish industries solely to produce more of the weld quality testing equipments locally in the country. This indeed, will help create more jobs and reduce the unemployment rates in the country.

Design of Control Kit for Arc Welding Process with Atomised Digital Controlled Welding System

This Research paper studies about the designing and simulation aspects of automatic arc welding system using digital control with the help of Proteus Simulation software. The welding sequence considered for the study consists of five intervals they are Standby, Squeeze, Weld, Hold, and Release intervals. A separate stepping interval circuit with a decoder to step the intervals from one to another is designed and analysis is done using a decoding technique. The designed stepping circuit ensures the correct order of the five intervals of the welding system, also a separate stepping of heat-cool sub intervals of weld interval is also designed with a user defined preset time counter circuit so that welding interval can be timed based on the user defined priority and can also be stepped between the two heat and cool sub intervals based on the total time assigned by the user. The digital automatic control system is developed to accurately control the arc welding system for welding of two given metal pieces. This report concerns automatic welding system with digital control and is directed to the improvement of certain drive and guide means for a relatively freely carried welding of wheel rim and wheel spider for continuous welding of a part resting on a freely rotatable table. The drive and guide means are carried on the welding head and impart drive to the part while maintaining the welding head properly positioned relative to the part. The system presented is a slightly simplified version of a real automobile wheel-welding system. Although system operation is explained in terms of wheel welding, the design of the system has much in common with other welding operations utilizing the basic industrial automatic welding sequence of Squeeze, Weld, Hold, Release, and Standby with digital control.

Analysis of Chinese Welding Industries Today and in the Future (Focus on Cost, Productivity, and Quality)

This paper make a detailed survey and research about the real situation about Chinese welding industry, and the future cooperation suggestion between Finland and China in this area. This topic was approached by searching for the latest and most accurate information through interviews, site visits, websites, books and promotional materials. The site visits are the most important. The destination cities in China cover a large range from northern to the southwestern areas in China. More than 15 professional welding factories or factories which have a welding workshop were visited, and based on discussions and an investigation in those factories; detailed and reliable data was collected. By using and analyzing that information, a general profile of modern Chinese welding factories was generated.

Reduction of Undercuts in Fillet Welded Joints Using Taguchi Optimization Method

This project work focuses on the reduction of weld undercuts using the Taguchi method. The phenomenon of weld undercuts constitutes a major problem for the welding industry. When undercuts occur, and particularly when such cuts are deep, it has a negative impact on the weld as it lowers the integrity and quality of the weldment. Therefore, efforts are made globally to reduce the depth of such weld undercuts to the barest minimum. Several optimization methods have been adopted; however, in this study, the Taguchi method is applied. “The smaller the better components” of the Taguchi method is applied. From the results obtained from applying this Taguchi method, the optimum process parameters obtained are A2-B1-C2, which are a voltage of 20 V, a current of 180 A, and a welding speed of 130 mm/s, required to form an undercut of 0.03 mm. Whereas the existing process parameters used by the company are A1-B3-C, which make an undercut to a depth of 0.09 mm. It is concluded that the use of Taguchi method has been able to reduce the depth of undercut as shown in this study. A step-by-step approach is presented in the study.

Development Research of a New Welding Manufacturing Quality Control and Management System (Case: China)

The Chinese welding industry is growing every year. Companies around the world are looking to use Chinese enterprises as their cooperation partners. However, the Chinese welding industry also has relatively low quality and weak management system. A modern, advanced welding management system appropriate for local socio-economic conditions is required to enable Chinese enterprises to enhance further their business development. This article designed and implemented a new welding quality management system in China. This new system is called ‘welding production quality control management model system in China’ (WQMC). Constructed on the basis of surveys and in-company interviews, the welding management system comprises the following different elements and perspectives: a ‘Localized congenital existing problem resolution strategies ’ (LCEPRS) database, a ‘human factor designed training system’ (HFDT) training strategy, the theory of modular design, ISO 3834 requirements, total welding management (TWM), and lean manufacturing (LEAN) theory. The paper also describes the design and implementation of a HFDT strategy in Chinese welding companies. Such training is an effective way to increase employees’ awareness of quality and issues associated with quality assurance. The study identified widely existing problems in the Chinese welding industry and constructed a LCEPRS database that can be used to mitigate and avoid common problems. The work uses the theory of modular design, and TWM as tools for the implementation of the WQMC system. Analysis of the WQMC system effects indicates that its adoption has resulted in improved quality and reduced costs.

Adaptive and Device Independent Planning Module for Task-Oriented Programming of Assembly Systems

The ability to enable a fast modification and system-change, in order to fulfil quickly changing market needs, is one of the essential requirements of future production systems. Two basic steps for an adaption of an automated production system to a new task are the reconfiguration and the reprogramming. Against this background, the central objective of this paper is the discussion of a new concept to simplify the application of task-oriented programming for assembly systems. Only abstract tasks are described in the task-oriented programming. The deduction of control code is done in a programming system.The advantages of task-oriented programming in means of time and complexity are often negated by the necessary effort to adapt a task-oriented programming system to the components and processes in a specific production system. Therefore, an adaptable task- oriented programming system that can be customized easily is the current research focus of the authors. The core of a task-oriented programming system is a planning module, in which the task description is transferred in code for the control of the system. Main subjects in the planning process are the separation in sub-steps as well as the identification of appropriate parameters and the chronological sequence of the sub-steps. Depending on the application (for example welding, gluing or pick and place operations) different algorithms and process knowledge are necessary. In this article a highly adaptable planning module based on a blackboard architecture and vendor independent device descriptions is discussed. The structural design of the planning module, its constituent parts and the description techniques for skills as well as products and processes are outlined. The advantages of the concept are illustrated by adapting the planning module for an industrial welding process.

Usability of arc types in industrial welding

Arc behaviour is a significant factor in all arc welding processes. Understanding of arc types and their inherent properties can help enhance weld prediction and weld quality and reduce welding cost and production cycle time. Advanced welding processes utilize real-time control and prediction, increasing the need for detailed knowledge of arc characteristics and arc applications. This paper analyses the types of welding arcs used in the welding industry, explains corresponding features and characteristics, provides guidance for suitable applications, and presents arc type comparisons, benefits, and weaknesses. The study is based on a review of the literature, and it provides a comprehensive overview of arc phenomena. The results of this work show that in many applications, greater benefit accrues from spray and pulsed arcs than short and globular arc modes. Controlled short arc, heavy deposition rate arc, and controlled spray arc are enhanced arc processes offering significant improvements in efficiency and usability. This review can assist companies in making appropriate choices of arc and welding process for different materials and applications. Furthermore, it can be utilized as a basis for further research.

Geometric Deformations of Welded Metallic Structures

Various research on the influence of different process parameters on quality characteristics of metallic structures assembled by welding have been accomplished [1 - 8, etc.]. The deformations of metallic structure components assembled by welding depend on the characteristics of the components, welded gap, welding speed, scheme and time of components fixing, etc. The paper presents the data and main results of an experimental research on the influence of two process parameters - the welding gap and the fixing time of the components - on the geometric deformations of certain metallic structure components in industrial conditions. Complex experiment and set-up including industrial welding robot and advanced measurement system have been designed and used. The geometric deformations of the welded metallic structure components are caused by forces and phenomenon heating - cooling, i.e. dilatation - contraction, respectively, acting during the periods of fixing - welding, fixing - cooling, cooling without fixing. Relevant dependences between the geometric deformation of welded structure and the considered influencing process parameters have been evidenced.

Control Of Puma-560 Robot Using Feedback Linearization Control Method And Kalman Filter Estimator For Regulation And Tracking Purpose

This research is presented to control a PUMA 560 robot which is well-known industrial robot with six degrees of freedom. It is a RRRRRR robot type which can do various tasks such as point welding in automotive industry and similar industries. The mathematical model is derived from dynamical equations by the means of Euler-Lagrange method. Stochastic feedback linearization with Kalman filter controller is implemented to control the PUMA 560 robot end effector.The regulation and tracking results are represented. The controller is examined in normal situation and even in presence of disturbances. Finally, the results indicate good performance of the controller.

Welding Simulation Used in the Design of Metallic Armor Systems

Welding steel armor reduces the armor materials protection capability. Several industrial and military welding standards exist for welding armor materials with the primary focus on joint strength rather than ballistic integrity.The Heat Affected Zone (HAZ) created by the welding process introduces vulnerabilities in the protection system. The process and designs that we have demonstrated include mitigation features that eliminate the ballistic degradation and provide uniform protection across all armor materials.In this study we used finite element simulation of the welding process to perform trade studies evaluating welded joint designs, and to show how the designs could be altered to both optimize armor performance and reduce welding heat input. A beneficial effect of reduced heat input was the corresponding reduction in welding-induced residual stresses, an overall reduction in assembly distortion in the assembly, and improvement of the armor performance.The simulated welding process included the creation of the heat affected zone and the development of residual stresses in the structure. ABAQUS finite element software was used for the simulation with the aid of an extensive material property database created over the wide range of welding temperatures.The finite element simulation predictions were validated and verified with excellent results by metallography and micro-hardness measurements. Live-fire ballistic tests were used as the final proof of measurable design improvements. Finite element welding simulation was shown to be an effective tool for improving upon standard welded armor designs, and above all in improving human safety.

X-Ray Analysis of Residual Stress in Weld Region of X70 Pipeline Steel

X-ray diffraction method has been used to analyze the residual stress distribution in weld region of an X70 pipeline steel before and after heat treatment. The welding process has been realized by industrial arc welding with circular weld seams. The effect of heat treatments on the level and the distribution of residual stresses were investigated. Stress distribution was characterized by relative high compressive stresses in weld seam just after welding. However, residual stress relaxation phenomenon was observed in weld region after heat treatments due to microstructure restoration and recrystalization. Optical microscope observation and Vickers hardness measurements were also realized as complementary microstructure characterization techniques.

Application of flux-cored wires for welding in industry

Application of flux-cored wires for welding in industry

Real Time Non-Destructive Testing Methods of Welding

This work presents a review of the three most efficient non-destructive testing methods. The methods are radiography, eddy current and ultrasonic inspection. These particular techniques were chosen because they are able to cover most of the industrial needs for welding joint inspection. The aim of this work is to present the physical background of operation for the given methods, discuss their benefits, limitations, and typical areas of application, and compare them with each other. In the first part of this work, all three methods and their variations are described in detail with schemes and figures which represent their working principles. It appears that, although all the given methods can detect all types of flaws in welded joints, they have their specific limitations. For example, ultrasonic testing is able to detect defects only in certain directions. The eddy current technique is also sensitive to defect direction, but it can be applied for inspecting conductive materials only. The main flaw of radiography is the resolution: it is not usable for very fine defects. The second part of the work is for comparing the testing methods and for drawing the conclusions. The methods are compared according to the possible materials, defect types and their position, as well as the possible areas of application. This part gives the background for choosing a proper welding joint testing method for certain applications in the welding industry.

Predicting residual stresses and distortion during multisequence welding of large size structures using FEM

A three-dimensional thermomechanical finite element (FE) analysis is carried out to model and predict the influence of welding sequence on the generation of distortions and residual stresses in large size T-joints. To simulate industrial welding conditions, the influence of nine welding sequences on the magnitude of distortion in both the plate and the stiffener was investigated. The addition of new material during welding was simulated using an element “birth and death” technique, while the moving welding arc was considered as a volumetric heat source with a double ellipsoidal distribution. The investigated material is a structural steel used for fabrication of large size structures in the hydroelectric industry. To calibrate the model and validate the simulation results, welding-induced distortion for one sequence was initially modeled and the results were compared with experimental measurements. The optimum welding sequences for the base plate and the reinforcement plate were determined. The results indicated also that the predicted distortions obtained from three-dimensional FE analysis are in reasonable agreement with experimental measurements.

Platform of Industrial Robot Task Simulation Used in Welding Automation

Based on the research progress of off-line programming system, propose a virtual manufacturing platform to simulate and monitor industrial robot welding task, by combining motion simulation of three-dimensional models, welding characteristics information-driven and monitoring communications. The platform designed as a three-dimensional solid modeling foreground, with kinematics algorithms and task characteristics as the core, to achieve a common solution that provide jobs simulation ,tatistical information and on-line monitoring. And there is a feasibility analysis of technical means.

Welding of Non Ferrous Metals - Indian Perspective

India's non-ferrous Welding industry, mainly consisting of Aluminium, Copper, Nickel, and Titanium, has travelled a long way from where it was a decade ago. In the next decade i.e. towards the end of 2020, the industry is expected to see a dramatic turnaround with lots of expansion plans running at full capacity. Hence it is a challenge for welding industry to cope up with the demand and technology. Also the consumption of the welding consumables as well as welding equipment will be in line with the demand. This article scope limits to review in general welding of Aluminium, Copper, Titanium, Nickel and its alloys with reference to the present scenario and road map.