1、Designation: A 997 07Standard 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 (e) 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 T
3、he values stated in SI units are to be regarded as thestandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applic
4、a-bility of regulatory limitations prior to use.2. Terminology2.1 Definitions of Terms Specific to This 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,
5、 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 linear depression in the castsurface whose length is less than three times its width. Surfacepits may be the result of gas or non metallic inclus
6、ions.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 should specify the followinginformation:3.1.1 Acceptance LevelMore than one acceptance levelmay be specified for different surfaces of the same cas
7、ting (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, and3.1.5 Additional acceptance criteria as applicable to all orportions of the casting surface.4. Acceptance Criteria4.1 Levels of acceptance for
8、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 removedby machining are considered acceptable.4.4 Surface discontinuities not covered in this practice shallbe a matter of agreement between the purchaser
9、 and themanufacturer.1This practice is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.18 on Castings.Current edition approved March 1, 2007. Published March 2007. Originallyapproved in 1998. Last previous e
10、dition approved in 2003 as A 997 98(2003)e1.TABLE 1 Visual Inspection Acceptance CriteriaA,BSurface Feature Level II Level III Level IVSurface PitsC,D,E0.030 in. (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
11、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) diameter 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 pe
12、rin.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.(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)0.45 in.(1.14 mm)SurfaceRoughnessE100 in. (2.5
13、 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 shall not violatedrawing minimum wall thickness.DSurface pits
14、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 2006.1*A Summary of Changes section appears a
15、t the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.SUMMARY OF CHANGESCommittee A01 has identified the location of selected changes to this standard since the last issue (A 997 98(2003) that may impact the use o
16、f this standard. (Approved March 1, 2007.)(1) Revised Table 1 to include investment casting conditions.ASTM 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 d
17、etermination 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
18、 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 receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel
19、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 International, 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).A997072
