Non-Destructive Testing for Field Welds: Real-Time Weld Quality Monitor

摘要

During the welding process, changes in arc voltage, travel speed, and heat input can occur without the operator's knowledge. These changes can cause defects such as porosity, slag inclusions, incomplete fusion, and undercut in the deposited weld metal. The cost of locating and repairing these defects can be a major portion of construction costs; welding inspection can constitute 25 to 40% of the weld fabrication cost. In addition, weld defects decrease service life of welded joints. Consequently, it is necessary to monitor the welding parameters to detect, identify, and locate possible defects. A weld monitor with real-time output would aid the inspector in designating suspect areas for non-destructing testing after welding. Further, a real-time weld quality monitor could be used to interrupt welding when defects are occurring thus precluding costly rework. To address this need, the US Army Construction Engineering Research Laboratory (CERL) is conducting research to develop a field-portable real-time weld quality monitor (WQM). (Author)