Problems in radiographic inspection of 2, 4, 6 and 8-mm thick steel welded plates

摘要

Based on the rules of the coming European Standard prEN-1435:1995 "Non-destructive examination of welded joints, the maximum permissible X-ray kilovoltages and the thickness-latitude were discussed in a previous article. Results were given for five different X-ray equipments and four radiographic film types. In this article concerning steel thicknesses 2-8 mm, the non-linear shape of the exposure curve for small thickness must be taken into account. The author considers a "point of homogeneity" below which the curve is non-linear, where exposure-times do not follow the half-logarithmic line in relation to material thickness and where thickness-latitude values are considerably smaller than might be expected.