Astm A802 - 19 Ev

 

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

 

Designation: A802 −  19

Standard Practice for

Steel Castings, Surface Acceptance Standards, Visual Examination1 This standard is issued under the fixed designation A802; the number immediately following the designation indicates the year of  original adoption or, in the case of revis original revision, ion, the year of last revision. revision. A number in paren parenthese thesess indicates the year of last reappr reapproval. oval. A superscript epsilon (´) indicates an editorial change since the last revision or reapproval. This standard has been approved for use by agencies of the U.S. Department of Defense.

1. Sco Scope* pe*

2. Terminology

1.1 1. 1 Th This is pr pract actice ice co cove vers rs th thee ac accep ceptan tance ce cr crite iteri riaa fo forr th thee surface inspection of steel castings by visual examination. Four levels of acceptance standards are provided. 1.2 Accep Acceptance tance levels utilize Steel Castings Research and Trade Association (SCRATA)2 graded reference comparators forr th fo thee vi visu sual al de dete term rmin inat atio ion n of su surf rfac acee te text xtur ure, e, su surf rfac acee roughness, and surface discontinuities described as follows: Acceptance levels A – Surface Texture B – Nonmetallic Inclusions C – Gas Porosity D – Solidification Discontinuities E – Sand Expansion Discontinuities F – Metal Inserts G – Thermally Cut Surfaces H – Mechanically Prepared Surfaces J – Welded Surfaces 1.3 Description Descriptionss of terms related to casting discontinuities discontinuities are in Section  Section   2. 1.4   This standar standard d doe doess not purport purport to add addre ress ss all of the safet sa fetyy co conc ncer erns ns,, if an anyy, as asso socia ciate ted d wi with th its us use. e. It is th thee responsibility of the user of this standard to establish appro priate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.5   This int intern ernati ationa onall sta standa ndard rd was dev develo eloped ped in acc accor or-dance with internationally recognized principles on standardizatio iza tion n es esta tabl blis ishe hed d in th thee De Decis cisio ion n on Pr Prin incip ciple less fo forr th thee  Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical  Barriers to Trade (TBT) Committee.

1 This practice is under the jurisd jurisdiction iction of ASTM Committee  Committee   A01   on Steel Steel,, Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee A01.18   on Castings. A01.18 Current Curre nt editio edition n approv approved ed Sept. 1, 2019. Publi Published shed October 2019. Originally approved in 1982. Last previous edition approved in 2015 as A802 – 95 (2015). DOI: 10.1520/A0802-19. 2 Available from Castings Technology International, Advanced Manufacturing Park, Par k, Bru Brunel nel Way ay,, Rot Rother herham ham,, S60 5WG 5WG,, Sou South th York orkshi shire, re, Eng Englan land. d. htt http:/ p://  / 

www.castingstechnology.com.

2.1  Definitions of Terms Specific to This Standard:  Expansion Discontinuities 2.1.1   rat tails, n— long, long, narrow, linear depressions or small steps occurring on a casting surface. Rat tails form as a result of san sand d exp expans ansion ion and min minor or buc buckli kling ng of the mold sur surfac facee during filling of the mold with liquid metal.

2.1.2  scab, n— a raised, rough area on a casting that usually cons co nsis ists ts of a cr crus ustt of me meta tall co cov ver erin ing g a la laye yerr of sa sand nd.. Sometimes, a scab consists of a raised, rough area of essentially solid metal on the surface of a casting. 2.1.3   veins, n— raised, raised, narrow, linear ridges that form upon cracking of the sand mold or core due to expansion of sand and the resulting mold or core stresses during filling of the mold with liquid steel.  External Chills

2.1.4   external chills, n— usually metal blocks, or graph graphite ite and an d car carbo bon n bl bloc ocks ks,, th that at ar aree in inco corp rpor orat ated ed in into to th thee mo mold ld to locally increase the rate of heat removal during solidification. Brackets have the same purpose but represent an integral part of the cast casting ing.. Bra Bracke ckets ts are pro produc duced ed by pro provid viding ing sui suitab table le cavities in the mold or core. External chills may produce flat spots and edges (raised areas or depressions) on the casting surface. Brackets merely chang surface. changee the casting appearance due to their presence. presence. Brackets may be removed or allowe allowed d to remain on the casting. 2.1.5  parting line and core print fins, n— thin thin projections of  excess metal at the parting plane between mold halves or core and mold. Causes are improper closing of the mold, insufficient weight wei ghting ing or clam clampin ping g of the mol mold d for pouring, pouring, or une uneven ven pattern surfaces at the matching locations. Core print fins are usually caused by improper dimensions of core prints of the pattern or core box, by rough placement of cores in a soft mold, or by inadequately secured cores. Fusion Discontinuities

2.1.6   gas por porosity osity,, n— a concav concavee discon discontinuity tinuity in castin castings gs due to the evolution of gas, either from the solidifying metal or the surrounding mold.

*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

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A802 − 19

interchangeable terms 2.1.7   laps, folds, and cold shuts, n— interchangeable to describe the appearance of the casting surface that is actually folded over. They develop due to low temperature, unfavorable flow conditions caused by oxide films, or combinations thereof. 2.1.8   misrun, misrun, n— an an inc incomp omplete letely ly for formed med cas casting ting,, due to only partial filling of the mold cavity when the liquid metal solidifi sol idifies es pre premat mature urely ly.. The res result ulting ing cas casting ting app appear earanc ancee is characterized by rounded edges, for a mild degree of misrun. Irregular, malformed edges of more severe misruns, and not fully forme formed d casting castings, s, are charac characteristic teristic.. Frequ Frequently ently,, misrun misrunss are associated with such discontinuities as wrinkles or laps and folds, or both. 2.1.9   wrinkl wrinkles, es, n— elo elonga ngated ted,, smo smooth oth dep depres ressio sions ns of the casting surface, frequently appearing in closely spaced groups. Wrinkles result from irregularities of the liquid metal flow in the mold cavity, frequently associated with low temperature, and are distinguished from the more severe phenomenon of  laps, folds, or cold shuts where the casting surface is actually folded over.  Inserts

2.1.10   chaplets, n— metallic metallic (steel) devices used to maintain the spacing between the core and the mold. Low liquid metal temperature and unfavorable flow conditions in the mold may produce insufficient fusion and cause irregular contact areas on the casting surface. 2.1.11   internal metallic llic (st (steel) eel) dev device icess use used d to internal chi chills, lls, n— meta locally increase the rate of heat removal during solidification. Incomp Inc omplete lete fus fusion ion due to low liqu liquid id stee steell temp tempera eratur tures es and prevailing prevai ling flow condit conditions ions may produ produce ce irreg irregularitie ularitiess of the surface similar to those that may be associated with chaplets. 2.1.12   linear elongated ated disco discontinui ntinuities ties linear discon discontinuitie tinuities, s, n— elong are considered linear if their length equals or exceeds three times the width. 2.1.12.1   cracks, cracks, n—c n—cold old and hot , less jag jagged ged,, som sometim etimes es straight ruptures that occur after solidification of the casting, due to excessive strain. Sometimes cracks are referred to as cold, hot, or heat-treat cracks to indicate the condition of the

removed remove d dur during ing the clea cleanin ning g pro process cess of pre pressu ssure re bla blastin sting. g. Surface discontinuities left by these inclusions are referred to by the inclusion type that caused their formation: 2.1.14.1   Discussion— Ceroxid Ceroxides es cau cause se dep depres ressio sions ns on the surf su rfac acee of th thee cas castin ting g by di disp splac lacem emen entt of mo molte lten n me metal tal.. Ceroxi Cer oxides des con consist sist of a mix mixtur turee of low low-me -meltin lting g oxi oxides des and partially fused sand. The crater-like appearance of the casting surface depression is typical. 2.1.14.2   Discussion— Depres D epressio sions ns on the cas casting ting sur surfac facee caused bya slag similarappearance to those caused ceroxides.and They differ by moreare rounded of theby depression do not exhibit the crater-like appearance of ceroxides. 2.1.14.3   Discussion— Depressions Depressions caused by sand are similar to those of ceroxides and slag. Their appearance may, at times, more closely reflect the granular nature of the sand. 2.1.15   shrinkage under risers and gates, and revealed by machining, n— a shrinkage void is a discontinuity in castings due to the lack of available liquid feed metal during solidification contraction. Riser removal and machining may reveal shrinkage that extends from the interior of the casting to the near surface area. 2.1.16   surfa cast st su surf rfac aces es ha have ve a mu mult ltiisurface ce tex textur ture, e, n— ca directi dir ectiona onall lay lay,, with without out the uni unifor form m seq sequen uence ce of rid ridges ges and valleys of machined surfaces. Welding

2.1.17   weld spatter, n— weld weld metal droplets that solidified against and adhere to the component being welded. 2.1.18   weld weld und under ercut cuts, s, n— narro narrow w elong elongated ated depre depressions ssions that border the weld contour and result from improper welding conditions or inadequate control of welding operations. 3. Order Ordering ing Information Information 3.1 The inq inquir uiry y and ord order er sho should uld spe specify cify the fol follow lowing ing information: 3.1.1   Acceptance Acceptance Level— Mor Moree tha than n one acce accepta ptance nce lev level el may be specified for different surfaces of the same casting (see Section   4), Section 3.1.2 If any types of discon discontinuit tinuities ies are unacce unacceptable, ptable,

castings, or the operation during which the cracks occur. 2.1.12.2  hot tears, n—  jagged ruptures in castings that occur during the final stages of solidification, while there is still some liquid in the interdendritic spaces, or shortly after solidification is complete.

4. Acce Acceptanc ptancee Stand Standards ards

2.1.13   meta flame me cu cutt ttin ing g an and d ai airr metall remo emova vall ma marks rks,, n— fla carbon-arc cutting produce parallel grooves in the cut-off area. Finer marks are produced with the abrasive cut-off wheel and grinding.

4.2 Sur Surfac facee dis discon contin tinuiti uities es not cov covere ered d in Pra Practic cticee A80 A802 2 shall be a matter of agreement between the purchaser and the manufacturer.

2.1.14   nonmetallic inclusions, n— casting surface inclusions such as ceroxides, slag, and sand are partially or completely

3.1.3 Extent of casting surfaces surfaces to be examin examined, ed, and 3.1.4 Numbe Numberr of castings to be examin examined. ed.

4.1 Levels of acceptance acceptance for visual inspection are listed in Table 1. 1.

5. Keywo Keywords rds 5.1 steel castings; castings; surf surface ace acceptance standards; standards; visual

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A802 − 19 TABLE 1 Visual Inspection Acceptance Criteria A Surface Feature Surface texture Nonmetallic inclusions Gas porosityB  Fusi Fu sion on di disc scon onti tinu nuit itie ies s Expa Ex pans nsio ion n di disc scon onti tinu nuit itie ies s Inserts Metal removal marks:  Thermal Mechanical Welds

Level I

Level II

Level III

Level IV

A1 B1 C2 . . .C  . . .C  . . .C 

A2 B2 C1 D1 . . .C  . . .C 

A3 B4 C3 D2 E3 F1

A4 B5 C4 D5 E5 F3

G1 H1 J1

G2 H3 J2

G3 H4 J3

G5 H5 J5

A

Level 1 is the highest acceptance acceptance level. Level IV is the lowest acceptance acceptance level. Comparator plates listed in higher acceptance levels are acceptable in all lower acceptance levels. B  See   Appendix X1. See X1. C  No reference comparator comparator plate is availa available ble for this surface feature and level.

APPENDIX (Nonmandatory Information) X1. NOTES ON GAS POROSITY COMPARA COMPARATOR TOR PLATES PLATES

X1.1 Compar Comparator ator plates C1 and C2 show different different types types of  porosity and surface roughness. C1 has fewer but larger pores with wit h a sm smoo ooth ther er su surf rfac acee fin finis ish, h, wh wher erea eass C2 ha hass a gr grea eater ter number of smaller pores with a rougher surface finish. This same allocation of C1 and C2 is also observed in ISO11971, EN12454, and EN1370. X1.2 ANSI/MSSX1.2 ANSI/MSS-SPSP-55 55 con consid siders ers that bot both h com compar parator ator plates C1 and C2 are equivalent to the acceptance criteria of  SP-55.

X1.3 The purchaser purchaser may choose to select more/smaller more/smaller or fewer/bigger as more important, but this is largely based on aesthetics and does not currently pertain to performance. X1.4 A purchaser purchaser is free to specify, specify, in agree agreement ment with the producer, the gas porosity comparator plate which better suits their application.

SUMMARY OF CHANGES Subcommittee A01.18 has identified the location of selected changes to this standard since the last issue (A802 – 95 (2015)) that may impact the use of this standard. (Approved Sep. 1, 2019.) (1)  Added footnotes B and C to  Table 1. 1. (2)  Added   Appendix X1   to further explain why comparators C1 and C2 are not in numerical order. ASTM International International takes no positi position on respecting the validi validity ty of any patent rights assert asserted ed in connec connection tion with any item mentio mentioned  ned  in this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk  of 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 and  if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards  and should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the  responsible respon sible technical technical committee, which you may attend. If you feel that your comments have not receiv received ed a fair hearing you should  make 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 above  address or at 610address 610-832832-9585 9585 (pho (phone), ne), 610610-832832-9555 9555 (fax (fax), ), or serv service@ ice@astm astm.org .org (e-m (e-mail) ail);; or thro through ugh the ASTM webs website  ite  (www.astm. (www .astm.org). org). Permission Permission rights to photocopy the standa standard rd may also be secure secured d from the Copyri Copyright ght Clearance Center, Center, 222  Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http://www.copyright.com/ 

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