Graded reference radiographs are intended to provide a guide enabling recognition of specific casting discontinuity types and relative severity levels that may be encountered during typical fabrication processes. Reference radiographs containing ungraded discontinuities are provided as a guide for recognition of a specific casting discontinuity type where severity levels are not needed. These reference radiographs are intended as a basis from which manufacturers and purchasers may, by mutual agreement, select particular discontinuity classes to serve as standards representing minimum levels of acceptability (see Sections 6 and 7).
Reference radiographs represented by this standard may be used, as agreed upon in a purchaser supplier agreement, for energy levels, thicknesses or both outside the range of this standard when determined applicable for the casting service application. Severity levels of similar discontinuity categories and energy level range of E186 reference radiographs may alternatively be used, as determined appropriate for the casting service application, if so agreed upon in the purchaser supplier agreement (see Note 2 and 5.1).
Procedures for evaluation of production radiographs using applicable reference radiographs of this standard are prescribed in Section 8; however, there may be manufacturing-purchaser issues involving specific casting service applications where it may be appropriate to modify or alter such requirements. Where such modifications may be appropriate for the casting application, all such changes shall be specifically called-out in the purchaser supplier agreement or contractual document. Section 9 addresses purchaser supplier requisites for where weld repairs may be required.
1.1 These reference radiographs illustrate various categories, types, and severity levels of discontinuities occurring in steel castings that have section thicknesses up to 2 in. (50.8 mm) (see Note 2). The reference radiograph films are an adjunct to this standard and must be purchased separately from ASTM International, if needed (see 2.2). Categories and severity levels for each discontinuity type represented by these reference radiographs are described in 1.2.
Note 18212;The basis of application for these reference radiographs requires a prior purchaser supplier agreement of radiographic examination attributes and classification criterion as described in Sections 4, 6, and 7 of this standard.
Note 28212;Reference radiographs previously used for this thickness range carried the designation E71, but included a now rarely used gamma source, that is, radium. The current document is also updated by inclusion of several recognized shrinkage or C categories and by elimination of the crack and hot tear categories except for one example of each of these discontinuity types. Reference radiographs for thicker sections may be found in Reference Radiograph standards E186 and E280. Reference Radiograph standards E446 and E186 provide some overlap of severity levels for similar discontinuity categories within the same energy level range (see 4.2, 5.1, and 6.3).
1.2 These reference radiographs consist of three separate volumes (see Note 3) as follows: (I) medium voltage (nominal 250-kV) X rays. (II) 1-MV X rays and Iridium-192 radiation, and (III) 2-MV to 4-MV ......
Copyright ©2024 All Rights Reserved