Welding ultrasonic scan

Ultrasonic reflections out of the weld volume are documented in a top and side view together with the area of weld volume scanned. A new coupling monitoring system ensures 100% coupling reliability. Furthermore the systems does not require any mechanics to monitor the probe position as the position data is monitored by airborne sound sensors. 

Besides spot welding, ultrasonics can be used to insert metals into plastic, stake materials to plastics, scan weld flat parts, and degate runner assemblies. 

N.Nielsen, P-scan system for ultrasonic weld inspection . The Danish Welding Institute, 1980. 

Having set up the ultrasonic instrument (according to test specifications), the inspector scans the weld volume. Any indications subject to recording are interpreted and documented in a handwritten on-site report. The test report only describes the indications detected by the inspector, but not the completeness of the lest in the sense of a documented 100% volume testing as is the case with X-ray testing. 

Another advantage with the system is that the quality of the scanning, in terms of the angle towards the weld and track partition is increased compared to manual ultrasonic testing due to the fact that the scanning technician is able to concentrate on the object rather than on the oscilloscope while scanning. 

The principal equipment for the ultrasonic examination is the P-scan system, PS-4, which is a computerised ultrasonic system, developed by FORCE Institute, for automatic, mechanical and manual ultrasonic examination of welds and materials. The system has documentation and storage facilities for all data related to each inspection operation, and includes visualisation of the inspection results in the form of images of the material volume examined. 

Strain aging can also occur in susceptible steels by welding near a crack, causing embrittlement (called dynamic strain aging). For this and other reasons, many users require that plate material intended for pressure-containing components be scanned by ultrasonic inspection equipment for cracks and flaws near edges to be welded. 

Ultrasonic welding the two basic techniques are plunge welding and continuous welding. In plunge welding, the parts are placed under a tool or horn the horn descends to the part under moderate pressure and the weld cycle is initiated. In the continuous welding process, the horn may scan the part or the material is passed over or under the horn on a continual basis. 

Inspection of the conical shell that helps to support the reactor core. The technique, which was developed in concert with the CEA/STA, was performed in late 1999. It involved ultrasonic testing of welds immersed in liquid sodium and located several meters from the scan surface. 

If presentation of data from ultrasonic examination of bellows restraint welds is restricted to D-scan i.e. assessment of defective weld area (structural strength), how can you ensure that no defect presents a potential leak path through the bellows wall This data would only be available from B-scan presentation. 

Then with the focused transducer activated, the probe was scanned across the weld area, under push-button control, to detect the lower edge of the unfused land. This point was then used as a datum to which all subsequent transducer positions were referred. If the operator was satisfied with the quality of signals obtained the automatic scanning facility was introduced. Most functions necessary to select the transducer and digitise and store the ultrasonic data were then performed automatically under micro-processor control. The sequence of such operations was as follows ... 

Direct assessment gives a possibility for direct mechanical or ultrasonic measurement of pit depth and wall thickness change due to the corrosion. X-ray radiography is used to inspect welds immediately after they are made. This technique can also show stress corrosion cracks and corrosion pits in the weld area, where the coating has failed to seal the metal structure. A promising method of mapping corrosion on the metal surface is the use of laser scanning equipment. 

---