As is well known that sensing and measuring the weld pool surface is very important to design intelligent welding machines which is able to imitate a skilled human welder who can choose suitable welding parameters. Therefore, in this paper, we concentrate the problem of weld pool surface 3D reconstruction, which is a key issue in intelligent welding machines development. Firstly, the framework ...

Characterization of flaws of weld bead is imperative for high-quality welding. Methods of weld bead inspection include radiographic, ultrasonic and vision inspection. However, such methods are costly and time consuming. The proposed sensor is light, low-cost and fast. This paper summarizes our work on weld bead monitoring and defect detection using an electromagnetic sensor. Measurements are ac...

This paper investigates the development of weld zone in Resistance Spot Welding (RSW) which focuses on weld nugget and Heat Affected Zone (HAZ). The effects of four factors namely weld current, weld time, electrode force and hold time were studied using a general 2 factorial design augmented by five centre points. The results of the analysis showed that all selected factors except hold time exh...

Welded joints of dissimilar steels are widely used in various components the steam-water circuit at thermal and nuclear power plants. In such welded after tempering during high-temperature operations, carbon migrates through fusion surface from less alloyed steel to more due difference chemical potential these steels. Decarburization weld-adjacent area ​​the heat affected zone steel, which occu...

The level of residual stresses generated in fusion welds has been a major area of interest for many years. For steels, a major influence on the final state of stress is through martensitic transformation. This is because the martensitic transformation is accompanied by significant shear and volume strains. One way to mitigate the development of residual stress is by controlling the onset of the...

In this Part II, a thorough investigation of the melting of the electrode; the droplet formation, detachment, transfer and impingement onto the workpiece, and the weld-pool formation and dynamics was conducted. The transient melt-flow velocity and temperature distributions in the droplet and in the weld pool were calculated. The resulting crater in the weld pool and the weld-pool oscillation du...

Resistance spot welding process is one of the very useful and widely utilized joining processes in automobile industry due to its high working speed, high productivity, flexibility and economical cost operation. In this paper various optimization techniques like Taguchi method, Artificial neural network (ANN), Genetic algorithm (GA) etc. and their applications are discussed to get the optimum w...

Weld overlay of piping was first used as a method to repair components of simple configurations which were known to contain cracking. An adequate ultrasonic examination of these geometries can be achieved by using a few conventional search units. Currently the application of pre-emptive weld overlays as a mitigation technique and/or to improve the examination surface condition for more complex ...

offshore pipelines are an effective tool for transportation of oil and gas which are usually assembled by the use of girth welds. since flaws may naturally exist at such welds, fracture assessment of girth welded offshore pipelines is substantial. current fracture assessment procedures like bs 7910 consider identical material properties for the weld and the base metals. however the strength dif...

The 700 °C power plants currently under development will utilize Ni-base alloys such as alloy 617 for components to be operated at temperatures >650 °C. Due to economic reasons for components or parts of components which are subjected to temperatures <650 °C, 2% Cr or 9-12% Cr steels is used, depending on the required mechanical properties. This makes the dissimilar joining of Ni-base alloys an...