METHOD FOR PICKING UP IMAGE OF FLAW OF WELDED PART OF STOPGAP WELDING STEEL PLATE

摘要

PURPOSE:To make it possible to perform the readjustment of a welded part only at a necessary part, by picking up the image of the flaw of the welded part of a steel plate so as to be capable of discriminating whether said flaw is positioned at the part belonging to an opening again opened at a normal position. CONSTITUTION:When radioactive rays are allowed to irradiate a steel plate 1 from the other surface side thereof, the transmission image 11 of the steel plate 1 is formed so that the part corresponding to the opening 7 of a mask plate 6 comes to a dark color. From the observation of this transmission image 11 in the welded part 2 of the steel plate 1, the part 2a belonging to the opening 4 to be opened to the steel plate at a normal position thereof corresponds to the dark color part 11a of the transmission image 11 and the part 2b belonging only to an opening 3 opened at a shifted position corresponds to the light color part 11b of the transmission image 11. Therefore, the flaw of the welded part 2 is projected on the film 5 in a state capable of discriminating whether the flaw is positioned at the part 2a belonging to the opening 4 to be opened at the normal position or at the part 2b belonging only to the opening 3 opened at the shifted position.