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适用范围：<p>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 may not be needed. These reference radiographs are intended as a basis from which manufacturers and purchasers may, by mutual agreement, select particular workmanship classes to serve as standards representing minimum levels of acceptability (see Sections 6 and 7).</p> <p>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. Overlapping severity levels of similar discontinuity categories and energy level range of <a href="http://myastm.astm.org/SUBSCRIPTION/NewValidateSubscription.cgi?E186-HTML">E186</a> reference radiographs may alternatively be used, as determined appropriate for the casting service application, if so agreed upon in a purchaser supplier agreement (see 5.1).</p> <p>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 where weld repairs may be required.</p><p id="s00002">1.1 These reference radiographs illustrate various categories, types, and severity levels of discontinuities occurring in steel castings that have section thicknesses of 4 <span class=''unicode''>x00BD;</span> to 12 in. (114 to 305 mm). The reference radiograph films are an adjunct to this document 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.</p> <p class="desc" id="N00001"> <span class="smallcap">Note</span> 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. Reference radiographs for other steel casting thicknesses may be found in Reference Radiograph standards <a href="http://myastm.astm.org/SUBSCRIPTION/NewValidateSubscription.cgi?E446-HTML">E446</a> and <a href="http://myastm.astm.org/SUBSCRIPTION/NewValidateSubscription.cgi?E186-HTML">E186</a>. Reference radiograph <a href="http://myastm.astm.org/SUBSCRIPTION/NewValidateSubscription.cgi?E186-HTML">E186</a> provides some overlap of severity levels for similar discontinuity categories within the same energy level range (see 4.2, 5.1, and 6.3).</p> <p id="s00044">1.2 These reference radiographs consist of two separate volumes as follows</p> <p id="s00003">1.2.1 <span class="italic"><span class="italic">Volume I: 2-MV X-rays and Cobalt-60</span>8212;</span>This includes cobalt-60 or equivalent isotope radiation and from 2-MV up to 4-MV X-rays. Set of 28 plates in 8<span class=''unicode''>x00BD;</span> by 11 in. (216 by 279 mm) ring binders.</p> <p id="s00004">1.2.2 <span class="italic"><span class="italic">Volume II: 4-MV to 30-MV X-rays</span>8212;</span>Set of 28 plates in 8 <small>¹/₂</small> by 11 in. (216 by 279 mm) ring binders.</p> <p id="s00005">1.2.3 Unless otherwise specified in a purchaser supplier agreement (see 1.1), each volume is for comparison only with production......