An improved welding electrode for producing weld metal having low amount of hydrogen therein so that hydrogen assisted cracking in weld zone is minimised. This is especially beneficial for welding high strength steel having tensile strengths of about 70000 psi or above. The reduction of slag /metal reaction temperature during welding have been found to have additional advantage of reducing the ...

The common commercial charge coupled device (CCD) camera is combined with a composite light filter to form a vision sensing system of low cost. It can capture the whole image of a weld pool clearly during constant-current gas tungsten arc welding (GTAW). Based on the imageprocessing algorithm, the edges of the weld pool under different welding conditions can be extracted. Calibration is made to...

Weld residual stresses often approach, or exceed, the yield strength of the material, with serious implications for the integrity of engineering structures. It is not always feasible to measure residual stresses, so integrity assessments often rely heavily on numerical models. In ferritic steels, the credibility of such models depends on their ability to account for solid-state phase transforma...

Observing the weld pool and measuring its geometrical parameters are important issues for automated and robotic welding, wherein the visual detection and localization of weld pool are critical steps. Previous methods of visual measurement of weld pool usually assume that the weld pool exists in a predefined area, and its contour should be a specific geometric shape and size. Furthermore, previo...

Comparison of welding influence on structural strength Al-Mg-Si alloy (AW6082-T6), supplied with 10 mm thick sheets, is made. Within the research tension and impact tests joints, made argon-arc friction stir welding, were carried out. During we observed following: plasticity decrease for joint zones, increase weld metal in defects strength.

A substantially successful technology that has emerged is the use of electro-optics, which has been expanded into the realm of ‘machine vision’ with the rapid advance in optical sensor technology and computer processing power. The basic principle of the optical sensor has remained unchanged over the years. Charge-Coupled Devices (CCDs), laser diodes and microprocessors form the basis of this ty...

An innovative laser-vision-based sensing method is proposed to measure weld pool oscillation frequency in pulsed gas tungsten arc welding (GTAW-P). A low-power five-line laser pattern is projected onto the entire weld pool surface as well as its reflection is intercepted by an imaging plane and captured by a high-speed camera. By observing and analyzing the change of the captured laser images d...