Weld Penetration Monitoring and Feedback Control in Submerged Arc Welding

This SBIR project aims at the development of an innovative technology that can be attached to existing submerged arc welding (SAW) systems to monitor and feedback control the depth of weld penetration. Existing SAW systems will be operated using existing welding procedures without modifications. In many applications skilled welders may adjust the welding parameters based on their observation of dynamic weld pool surface to successfully control the weld penetration. Although for SAW the weld pool surface is not observable, it may/should still provide necessary information to estimate the weld penetration. A method is thus proposed to generate a dynamic change in submerged arc weld pool and then estimate this change from arc electrical signals that can be easily measured. The Phase I project aims at proving the feasibility of the proposed method through developing a laboratory monitoring/control system, using it to feedback control the weld penetration at different levels, and verifying the monitoring/control accuracy through comparison with actual welds. The Phase II project will develop a commercial prototype system, demonstrate benefits through increasing the thickness for no back-gouging two-sided butt welding, on-site demonstrate the system and benefits at selected shipyards, and prepare for the military qualification and transition.