ULTRASONIC MONITORING AND CONTROL DURING ARC FUSION WELDING

Abstract

Abstract Ultrasonic examinations were first shown to be capable of detecting weld pools in 1978 using simple N.D.T. techniques and manual metallic arc welding. Further work, using submerged arc welding, demonstrated that the best technique was to employ shear waves operated from the upper plate surface. A control alogarithm relating beam path length to welding current was identified and used to control penetration depths to within 1mm of desired depth. Utilising ultrasonic beam spread has been shown also to monitor the seam immediately in front of the weld pool. Seam tracking simultaneously with penetration control is therefore possible from one piece of apparatus.