1、Designation: A997 08 (Reapproved 2018)Standard Practice forInvestment Castings, Surface Acceptance Standards, VisualExamination1This standard is issued under the fixed designation A997; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisio
2、n, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers the acceptance criteria for surfaceinspection of investment castings by visual exa
3、mination.1.2 The 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
4、any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internati
5、onally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Terminology2.1 Definitions of Terms Specific to T
6、his Standard:2.1.1 linear discontinuity, na discontinuity 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 surface,usually associated with the breakdown of the mold and itsrepla
7、cement with the casting metal.2.1.3 surface pit, na nonlinear 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 texture,usually determined by the use of a compa
8、rator.3. Ordering Information3.1 The inquiry or order should 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 t
9、o be examined,3.1.4 Number of castings to be examined, 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 S
10、urface roughness and surface pits that will be removedby 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,Stainl
11、ess Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.18 on Castings.Current edition approved March 1, 2018. Published March 2018. Originallyapproved in 1998. Last previous edition approved in 2012 as A997 08 (2012).DOI: 10.1520/A0997-08R18.Copyright ASTM International, 10
12、0 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and R
13、ecommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that deter
14、mination 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 time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or
15、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 receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that
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18、t Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 1 Visual Inspection Acceptance CriteriaA,BSurface Feature Level II Level III Level IVSurface PitsC,D,E0.030 in. (0.76 mm)diameter by 0.015 in.(0.38 mm) deep withno more than 1 per in.2(645 mm2)0.060 in. (1.52 mm)di
19、ameter by 0.030 in.(0.76 mm) deep withno more than 1 per in.2(645 mm2)0.060 in. (1.52 mm)diameter by 0.030 in.(0.76 mm) deep withno more than 4 per in.2(645 mm2)Positive MetalD,E0.060 in. (1.52 mm)diameter by 0.015 in.(0.38 mm) high withno more than 1 per in.2(645 mm2)0.125 in. (3.18 mm)diameter by
20、0.030 in.(0.76 mm) high withno more than 1 per in.2(645 mm2)0.125 in. (3.18 mm)diameter by 0.030 in.(0.76 mm) high withno more than 4 per in.2(645 mm2)Parting Line andEjector Pin MarksHeight or DepthC0.005 in. (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.
21、 (0.76 mm) 0.045 in. (1.14 mm)Surface RoughnessE100 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 depending on need.CMaximum surface pit, parting line, and ejector pin mark depth sh
22、all 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 comparator or tactile source.FMachined and non-machined surfacesValue was editorially corrected in June 2006.A997 08 (2018)2
