Manufacture of deliberate welding defects for NDT research

The paper concerns deliberate welding defects which are of use in non-destructive testing (NDT) studies of weld defects which could occur in pressurized water reactor (PWR) vessels. A description is given of weld defects in PWR vessels, including the defect size distribution and defect orientation. The manufacture of deliberate defects for use in NDT studies is outlined, along with the problems of ensuring realistic defects while attempting to control their locations, numbers and sizes. Specific techniques used to make slag, lack of fusion, weld metal cracks, and heat-affected zone cracks of different types in submerged-arc weldments are outlined. (UK)