ASTM International has announced a new standard reference for inspecting aluminum castings, but developing ASTM standard E 2422, Reference Digital Images for Inspection of Aluminum Castings, involved more than digitizing the images used in the current standard E 155, Reference Radiographs for Inspection of Aluminum and Magnesium Castings.
According to Michael Horky, principal level III, RT, Boeing Commercial Airplanes, creating the new standard required the ASTM task group members to understand the spatial resolution differences between various detectors, contrast differences, which digitization scan resolution was appropriate, and a process for normalizing the digital images for various digital systems in the industry.
ASTM E 2422 was developed by Subcommittee E07.02 on Reference Radiological Images, which is under the jurisdiction of ASTM International Committee E07 on Nondestructive Testing. Horky says that E 2422 will be used by facilities that inspected aluminum castings via digital radiography. "This opens the door for inspecting production hardware, which was not allowed in many industries before this standard was developed," he says.
E 2422 is focused on aluminum, but Subcommittee E07.02 has formed a task group for making digital images for ASTM E 192, Reference Radiographs for Investment Steel Castings of Aerospace Applications. According to Horky, there is a foreseeable need for digital images for magnesium and other metals, and he notes that the task group that worked on E 2422 documented the development process so that it could be used to design digital images for other metals.