TWI Industrial Member Report Summary 613/1997
B W Kenzie and B G I Dance
Commercial use of high power electron beam (EB) welding for thick section (50-200mm) fabrication has been a reality for two decades. Using high power, large vacuum chamber facilities, eg TWI's 100kW 150kV, 150m 3 EB system, it is possible to weld components in these thicknesses with great speed and precision. Since the majority of these components are of high value and frequently operate in critical situations, a high level of quality control is important. Fortunately, the EB welding process is usually fully automated, thus ensuring that defective welds are relatively uncommon. However, postweld inspection is normally a requirement.
Although a provisional European Standard prEN ISO 13919-1 [1] is now available which specifies quality levels for EB welds in material thickness up to 50mm, many existing weld quality standards and non-destructive testing (NDT) standards were originally devised with arc welding processes in mind.
Objective
- To assess the performance of currently available NDT techniques for detection and sizing of buried flaws that might occur during high power EB welding of thick section (125-150mm) ferritic steel.