1、Designation: A 997 08Standard Practice forInvestment Castings, Surface Acceptance Standards, VisualExamination1This standard is issued under the fixed designation A 997; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of l
2、ast revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This practice covers the acceptance criteria for surfaceinspection of investment castings by visual examination.1.2 Th
3、e values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated
4、 with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Terminology2.1 Definitions of Terms Specific to This Standard:2.1.1 linear discontinuity, na discontinu
5、ity whose lengthis equal to or greater than three times its width. Cracks and coldshuts are examples of linear discontinuity.2.1.2 positive metal, nraised metal on the casting surfaceusually associated with the breakdown of the mold and itsreplacement with the casting metal.2.1.3 surface pit, na non
6、 linear depression in the castsurface whose length is less than three times its width. Surfacepits may be the result of gas or non metallic inclusions.2.1.4 surface roughness, na measure of surface textureusually determined by the use of a comparator.3. Ordering Information3.1 The inquiry or order s
7、hould specify the followinginformation:3.1.1 Acceptance LevelMore than one acceptance levelmay be specified for different surfaces of the same casting (seeSection 4),3.1.2 If any types of discontinuities are unacceptable,3.1.3 Casting surfaces to be examined,3.1.4 Number of castings to be examined,
8、and3.1.5 Additional acceptance criteria as applicable to all orportions of the casting surface.4. Acceptance Criteria4.1 Levels of acceptance for visual inspection are listed inTable 1.4.2 Parts shall not exhibit any linear discontinuities.4.3 Surface roughness and surface pits that will be removedb
9、y machining are considered acceptable.4.4 Surface discontinuities not covered in this practice shallbe a matter of agreement between the purchaser and themanufacturer.1This practice is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsi
10、bility of SubcommitteeA01.18 on Castings.Current edition approved Nov. 1, 2008. Published December 2008. Originallyapproved in 1998. Last previous edition approved in 2007 as A 997 07.TABLE 1 Visual Inspection Acceptance CriteriaA,BSurface Feature Level II Level III Level IVSurface PitsC,D,E0.030 in
11、. (0.76mm) diameter by0.015 in. (0.38mm) deep with nomore than 1 perin.2(645 mm2)0.060 in. (1.52mm) diameter by0.030 in. (0.76mm) deep with nomore than 1 perin.2(645 mm2)0.060 in. (1.52mm) diameter by0.030 in. (0.76mm) deep with nomore than 4 perin.2(645 mm2)Positive MetalD,E0.060 in. (1.52mm) diame
12、ter by0.015 in. (0.38mm) high with nomore than 1 perin.2(645 mm2)0.125 in. (3.18mm) diameter by0.030 in. (0.76mm) high with nomore than 1 perin.2(645 mm2)0.125 in. (3.18mm) diameter by0.030 in. (0.76mm) high with nomore than 4 perin.2(645 mm2)Parting Line andEjector Pin MarksHeight or DepthC0.005 in
13、.(0.13 mm)0.010 in.(0.25 mm)0.020 in.(0.51 mm)Gate HeightF0.015 in.(0.38 mm)0.030 in.(0.76 mm)0.045 in.(1.14 mm)SurfaceRoughnessE100 in. (2.5 m) 125 in. (3.2 m) 200 in. (5.0 m)AFeatures in excess of those specified in the table are not acceptable.BLevel I criteria may be established in the future de
14、pending on need.CMaximum surface pit, parting line, and ejector pin mark depth shall not violatedrawing minimum wall thickness.DSurface pits or positive metal less than 0.010 in. (0.25 mm) diameter and lessthan 0.010 in. (0.25 mm) deep or high shall be considered non-relevant.EDetermined by comparat
15、or or tactile source.FMachined and non-machined surfacesValue was editorially corrected in June 2006.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.SUMMARY OF CHANGES
16、CommitteeA01 has identified the location of selected changes to this standard since the last issue (A 997 07)that may impact the use of this standard. (Approved Nov. 1, 2008.)(1) Revised Table 1, Level IV, Gate Height.ASTM International takes no position respecting the validity of any patent rights
17、asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any tim
18、e by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will r
19、eceive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM I
20、nternational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).A997082
