1、Designation: E2669 11E2669 16Standard Digital Reference Images forTitanium Castings1This standard is issued under the fixed designation E2669; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in p
2、arentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 The digital reference images provided in the adjunctadjuncts to this standard illustrate various types and degrees ofdiscontinuities occurring in
3、 titanium castings.2 Use of this standard for the specification or grading of castings requiresprocurement of the appropriate adjunct digital reference images, which illustrate the discontinuity types and severity levels. Theyare intended to provide the following:1.1.1 Aguide enabling recognition of
4、 titanium casting discontinuities and their differentiation both as to type and degree throughdigital radiographic examination.1.1.2 Example digital radiographic illustrations of discontinuities and a nomenclature for reference in acceptance standards,specifications and drawings.1.2 The digital refe
5、rence images consist of seventeentwenty-five digital files each illustrating eight grades of increasing severity.TheVolume I files illustrate seven common discontinuity types representing casting sections up to 1-in. (25.4-mm).1 in. (25.4 mm).The Volume II files illustrate five discontinuity types r
6、epresenting casting sections over 1 in. (25.4 mm) to 2 in. (50.8 mm) inthickness.1.3 The reference radiographs were developed for casting sections up to 1 in. (25.4 mm) in thickness.1.3 All areas of this standard may be open to agreement between the cognizant engineering organization and the supplie
7、r, orspecific direction from the cognizant engineering organization. These items should be addressed in the purchase order or thecontract.NOTE 1The digital reference images are available from ASTM International Headquarters. Order number RRE2669. RRE266901 and RRE266902.Each of the digital reference
8、 images contain an image of a step wedge density scale and two duplex-wire gauges. Refer to Practice E2002 for wire pairdetails. Originally, only Volume I images were available and some sets may identify these only as RRE2669 without a volume designation. They remainvalid for use as Volume I images
9、(RRE266901)1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information only and are not considered standard.1.5 These digital reference images are not intended to illustrate the ty
10、pes or degrees of discontinuities when performing filmradiography. If performing film radiography of titanium castings, refer to Reference Radiographs E1320.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user
11、of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.1.7 Only licensed copies of the software and images shall be utilized for production inspection. A copy of the ASTM/Userlicense agreement shall be kept on file
12、for audit purposes.2. Referenced Documents2.1 ASTM Standards:3E94 Guide for Radiographic Examination1 This standard is under the jurisdiction of ASTM Committee E07 on Nondestructive Testing and is the direct responsibility of Subcommittee E07.02 on ReferenceRadiological Images.Current edition approv
13、ed Dec. 1, 2011June 1, 2016. Published December 2011June 2016. Originally approved in 2010. Last previous edition approved in 20102011 asE2669 - 10.E2669 - 11. DOI:10.1520/E2669-11.DOI:10.1520/E2669-16.2 The digital reference images are considered to be applicable to all titanium castings, requiring
14、 close tolerances. Castings for which these images are applicable generallyinclude those made by the lost wax, frozen mercury, ceramicast or shell mold processes.3 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book o
15、f ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technical
16、ly possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this stan
17、dardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1E1025 Practice for Design, Manufacture, and Material Grouping Classification of Hole-Type Image Quality Indicators (IQI)Used for RadiologyE1316 Terminology for Nondestructive Examina
18、tionsE1320 Reference Radiographs for Titanium CastingsE2002 Practice for Determining Total Image Unsharpness and Basic Spatial Resolution in Radiography and RadioscopyE2597 Practice for Manufacturing Characterization of Digital Detector Arrays2.2 SMPTE Practice:4RP1332.3 ASTM Adjuncts:Digital Refere
19、nce Images of Investment Steel Castings for Aerospace Applicationsfor Titanium Castings:Volume I: Applicable for Thicknesses up to 1 in. (25.4 mm)5Volume II: Applicable for Thicknesses over 1 in. (25.4 mm) to 2 in. (50.8 mm)63. Terminology3.1 DefinitionsDefinitions of terms used in this standard may
20、 be found in Terminology E1316.3.2 Definitions of Terms Specific to This Standard:3.2.1 The terms relating to discontinuities used in these digital reference images are described based upon radiographicappearance when viewed in the negative polarity such that the images appear in the same sense as t
21、hey would when viewed onX-ray film. If images are viewed in the positive polarity, the terms lighter and darker will need to be reversed.3.2.2 aliasingartifacts that appear in an image when the spatial frequency of the input is higher than the output is capable ofreproducing. This will often appear
22、as jagged or stepped sections in a line or as moir patterns.3.2.3 contrast normalizationthe adjustment of contrast between the production image and the reference image that makes thechange in digital driving level versus change in thickness equal for both images.3.2.4 DDLdigital driving level also k
23、nown as monitor pixel value.3.2.5 system resolutionthe detector-measured resolution divided by the geometric magnification.3.2.6 gasGas in its various forms is usually caused by the reaction of molten titanium with the mold or residual material leftin the mold. Gas tends to migrate to the upper port
24、ions of the casting. The formation of clustered or scattered gas holes results fromthe generation of larger amounts of gas than a single gas hole. Whether the larger amount of gas spreads out or is confined to asmall area is dependent upon a number of factors including casting process, reaction area
25、, solidification rate, wall thickness, andgeometry.3.2.6.1 gas holesspherical voids formed through the release and subsequent entrapment of gas during solidification.Agas holewill appear as a dark round spot on the digital image.3.2.6.2 clustered gas holesa closely nested group of dark round voids c
26、oncentrated within a self-defined boundary area.3.2.6.3 scattered gas holesmultiple voids appearing as dark round spots on the digital image. They are randomly spreadthroughout a part or area of a part to a lesser concentration than clustered gas holes but with the potential to degrade the castingth
27、rough their interaction which precludes their evaluation on an individual basis.3.2.7 shrinkageWhile at times the appearance of shrinkage in titanium may be radiographically similar to shrinkage in steel,the faster solidification rate of titanium has a dramatic effect on the conditions under which e
28、ach shrinkage type will occur intitanium. Other factors which influence the formation of shrinkage are wall thickness and thickness transition gradients, gate sizeand orientation, mold design, casting configuration, metal/mold temperature, and pouring rate and method. All the types ofshrinkage descr
29、ibed in 3.2.7.1 through 3.2.7.3 have a degree of overlap. However, each is most likely to occur under a specificset of conditions primarily influenced by metal feed, section thickness and cooling rate.3.2.7.1 shrinkage cavityappears as a dark void with smooth sides taking an appearance very similar
30、to a gas hole.Ashrinkagecavity, particularly in thicker wall sections, is usually larger than a single gas hole would be. The cavity is formed during thecooling process due to a lack of feeding metal. The cavity compensates for the rapid solidification taking place at the surface ofthe casting, ther
31、eby forming the cavity in the center area of the wall. Shrinkage cavity has a definite tendency to occur near hotspots where walls are 12-in. (12.7-mm) thick or more.3.2.7.2 scattered shrinkageappears on a digital image as dark fine lacy or filamentary voids of varying densities. These voidsare usua
32、lly uniformly spread throughout the area of the casting where shrinkage is occurring and are relatively shallow.3.2.7.3 shrinkage, centerlinecharacterized by a more discrete dark indication than scattered shrinkage. The indication hasdefinite borders consisting of a lacy network of varying density o
33、r a network of interconnected elongated voids. Centerlineshrinkage is located primarily in the center of the material cross section with a tendency to orient toward gates or risers.4 Available from Society of Motion Picture and Television Engineers, 3 Barker Avenue, White Plains, NY 10601; or www.sm
34、pte.org/smpte_store/5 Available from ASTM International Headquarters. Order Adjunct No. RRE2669RRE266901.6 Available from ASTM International Headquarters. Order Adjunct No. RRE266902.E2669 1623.2.8 foreign material, less denseappear as dark indications in a variety of shapes and sizes on a digital i
35、mage. Inclusions maybe found in groups or appear singularly. Less dense inclusions can be caused by contaminants in the molten titanium, residualmaterials left on the surface of the mold, or broken pieces of the mold becoming entrapped during solidification.3.2.9 foreign material, more denseappear a
36、s light indications in a variety of shapes and sizes on a digital image. More denseinclusions can be caused by contaminants introduced in the same manner as less dense inclusions, or tungsten introduced duringweld repairs.4. Significance and Use74.1 These digital reference images are intended for re
37、ference only, but are designed such that acceptance standards, which maybe developed for particular requirements, can be specified in terms of these digital reference images. The illustrations are digitalimages of castings that were produced under conditions designed to develop the discontinuities.4
38、.1.1 Applicability of Thickness Designations:4.1.1.1 Clustered holes, scattered gas holes, scattered shrinkage cavity, centerline shrinkageThe discontinuity types, illustratedthickness and applicable thickness range are summarized in Table 1 for the Volume I images and in Table 2 for the Volume IIim
39、ages.(1) The images of the 14-in. (6.4-mm) castings are intended to be used in the thickness range up to and including 38-in.(9.5-mm). The images of the 12-in. (12.7-mm) castings are intended to be used in the thickness range of over 38-in. (9.5-mm), upto and including 58-in. (15.9-mm). The images o
40、f the 34-in. (19.1-mm) castings are intended to be used in the thickness range ofover 58-in. (15.9-mm), up to and including 1-in. (25.4-mm).4.1.1.2 Shrinkage Cavity:(1) The images of the 12-in. (12.7-mm) castings are intended to be used in the thickness range up to and including 58-in.(15.9-mm). The
41、 images of the 34-in. (19.1-mm) castings are intended to be used in the thickness range over 58-in. (15.9-mm) to1-in. (25.4-mm).4.1.1.3 Gas hole; foreign material, less dense; foreign material, more dense(1) The images are intended to be used in the thickness range up to and including 1-in. (25.4-mm
42、).4.2 Image DeteriorationMany conditions can affect the appearance and functionality of digital reference images. Forexample, electrical interference, hardware incompatibilities, and corrupted files and drivers may affect their appearance. ThePractice E2002 line pair gauges located in each digital r
43、eference image can be used as an aid to detect image deterioration bycomparing the measured resolution using the gauges to the resolution stated on the digital reference image. Do not use the digitalreference images if their appearance has been adversely affected such that the interpretation and use
44、 of the images could beinfluenced.4.3 Agreement should be reached between cognizant engineering organization and the supplier that the system used by thesupplier is capable of detecting and classifying the required discontinuities.5. Basis of Application5.1 The digital reference images may be applie
45、d as acceptance standards tailored to the end use of the product. Application ofthese digital reference images as acceptance standards should be based on the intended use of the product and the followingconsiderations (see Note 2).7 Astudy was performed that compared film to digital modalities for t
46、he classification of aluminum casting discontinuities. Results of this study are available fromASTMas RR:E07-1004.Asubsequent study was performed that compared film to digital modalities for the classification of titanium and steel casting discontinuities. Results of thisstudy are available from AST
47、M as RR:E07-1006.TABLE 1 Volume I Digital Reference Images for Titanium Castings up to 1 in. 25.4 mmDiscontinuity Casting Process Alloy Plate Thickness, in. Applicable Casting Thickness, in.Gas hole Centrifugal ram graphite Ti 6AL 4V N/A Up to 1Clustered gas holes Centrifugal precision Ti 6AL 4V 14
48、Up to 38Clustered gas holes Centrifugal precision Ti 6AL 4V 12 Over 38 to 58Clustered gas holes Centrifugal precision Ti 6AL 4V 34 Over 58 to 1Scattered gas holes Top pour lost wax Ti 6AL 4V 14 Up to 38Scattered gas holes Top pour lost wax Ti 6AL 4V 12 Over 38 to 58Scattered gas holes Top pour lost
49、wax Ti 6AL 4V 34 Over 58 to 1Shrinkage cavity Centrifugal ram graphite Ti 6AL 4V 12 Over 14 to 58Shrinkage cavity Centrifugal ram graphite Ti 6AL 4V 34 Over 58 to 1Scattered shrinkage cavity Top pour lost wax Ti 6AL 4V 14 Up to 38Scattered shrinkage cavity Top pour lost wax Ti 6AL 4V 12 Over 38 to 58Scattered shrinkage cavity Top pour lost wax Ti 6AL 4V 34 Over 58 to 1Centerline shrinkage Centrifugal ram graphite Ti 6AL 4V 14 Up to 38Centerline shrinkage Centrifugal ram graphite Ti 6AL 4V 12 Over 38 to 58Centerline shrin
