1、Designation: A 456/A 456M 99 (Reapproved 2003)Standard Specification forMagnetic Particle Examination of Large CrankshaftForgings1This standard is issued under the fixed designation A 456/A 456M; the number immediately following the designation indicates the yearof original adoption or, in the case
2、of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This is an acceptance specification for the magneticparticle inspection of forged steel cran
3、kshafts having mainbearing journals or crankpins 4 in. 200 mm or larger indiameter.1.2 There are three classes, with acceptance standards ofincreasing severity:1.2.1 Class 1.1.2.2 Class 2 (originally the sole acceptance standard ofSpecification A 456).1.2.3 Class 3 (formerly covered in Supplementary
4、 Require-ment S1 of Specification A 45664 (1970).1.3 This specification is not intended to cover continuousgrain flow crankshafts, however, Test Method A 983/A 983Mmay be used for this purpose.NOTE 1Specification A 668/A 688M is a product specification whichmay be used for crankshaft forgings.1.4 Th
5、e values stated in either inches or SI (metric) units areto be regarded separately as the standard. Within the text andfigures, the SI units are shown in brackets. The values stated ineach system are not exact equivalents; therefore each systemshall be used independently of the other. Combining valu
6、esfrom the two systems may result in nonconformance with thespecification.1.5 Unless the order specifies the applicable “M” specifica-tion designation, the material shall be furnished to the inchunits.2. Referenced Documents2.1 ASTM Standards:2A 275/A 275M Test Method for Magnetic Particle Exami-nat
7、ion of Steel ForgingsA 668/A 668M Specification for Steel Forgings, Carbonand Alloy, for General Industrial UseA 966/A 966M Test Method for Magnetic Particle Exami-nation of Steel Forgings Using Alternating CurrentA 983/A 983M Specification for Continuous Grain FlowForged Carbon and Alloy Steel Cran
8、kshafts for MediumSpeed Diesel EnginesE 1417 Practice for Liquid Penetrant Examination3. Classification of Indications3.1 Magnetic particle indications on the surface of thecrankshaft shall be classified as follows:3.1.1 Open cracks, flake, or pipe.3.1.2 Nonmetallic inclusions or stringers occurring
9、 in alongitudinal direction.3.1.3 Twist cracks or nonmetallic inclusions usually occur-ring at 45 to 70 from the axis of the journal.3.2 They shall also be classified as follows:3.2.1 Open indications are visible after removal of themagnetic particles or can be detected by the use of contrast dyepen
10、etrant, as described in Type II of Practice E 1417.3.2.1.1 Pinpoint indications are open indications116 in.1.5 mm in maximum dimension, as detected by application ofType II of Practice E 1417.3.2.2 Non-open indications are indications which are notvisually detectable as described in 3.2.1.4. Orderin
11、g Information4.1 The inquiry and purchase agreement shall contain astatement that the crankshaft(s) is (are) to be subject toacceptance according to this specification. If reference to classis omitted, Class 2 shall apply.4.2 The use of Supplementary Requirements S1 and S2should be specified if requ
12、ired.5. Procedure5.1 Magnetic particle inspection shall be conducted accord-ing to Test Method A 966/A 966M, except when Supplemen-tary Requirement S1 is to be used. The use of prod typecontacts is not permitted on finished crankshafts. Magnetic1This specification is under the jurisdiction of ASTM C
13、ommittee A01 on Steel,Stainless Steel, and Related Alloys , and is the direct responsibility of SubcommitteeA01.06 on Steel Forgings and Billets.Current edition approved Oct. 1, 2003. Published November 2003. Originallyapproved in 1999. Last previous edition approved in 1999 as A 45699.2For referenc
14、ed ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Co
15、nshohocken, PA 19428-2959, United States.leeches may only be used on noncritical parts of the crankshaftwhen Supplementary Requirement S2 is utilized.6. Areas of Inspection6.1 Major Critical Areas:6.1.1 The critical area of any crankpin shall be that area plusor minus 60 from the 6 oclock position o
16、f the pin extending38 in. 10 mm above the thrust collar around the fillet, and58in. 16 mm into the pin along its axis measured fromapproximately the blend of the pin surface and fillet, as shownin Fig. 1 and Fig. 2.6.1.2 The critical areas of any main bearing journal shall bethat area plus or minus
17、60 from the 12 oclock position on topof the journal extending38 in. 9.5 mm above the thrustcollar around the fillet and58 in. 15.9 mm into the journalalong its axis measured from approximately the blend of thejournal surface and the fillet, as shown in Fig. 1 and Fig. 2.6.1.3 The critical area of an
18、y crankpin or main journal alsoincludes that surface area closer than14 in. 6 mm to thejunction of the radius blend and the journal surface of any oilhole.6.2 Minor Critical AreasMinor critical areas include allmachined fillets, thrust bearing, and bearing surfaces notspecified as major critical are
19、as.7. Acceptance Standards7.1 Class 1:7.1.1 Major Critical Areas:7.1.1.1 Open indications over14 in. 6 mm in length shallbe removed by dimpling to a depth no greater than316 in. 5mm. Open indications over116 to14 in. 1.5 to 6 mm inlength shall be depressed as in 7.2.2.3.7.1.1.2 Pinpoint indications
20、are permissible, except in clus-ters of more than 5 in any14 by14-in. 6 by 6-mm area, inwhich case they must be dimpled to a depth of no more than316in. 5 mm. If they do not open or increase in number they areacceptable and need not be removed.7.1.1.3 Non-open indications are acceptable up to andinc
21、luding12 in. 13 mm in length. If non-open indications areover12 in., depress, and if they are not open or are worsening,accept them. Otherwise remove by dimpling to a maximumdepth of316 in. 5 mm.7.1.1.4 The total area of dimples shall be limited as in7.2.1.3.7.1.2 Minor Critical Areas:7.1.2.1 Open i
22、ndications oriented at an angle in excess of30 to the longitudinal axis must be removed to a depth notexceeding316 in. 5 mm, by dimpling.7.1.2.2 Open indications longer than 112 in. 35 mmindividually or more than 3 in. 75 mm of total length perbearing journal, that are parallel to the longitudinal a
23、xis within30, must be removed by dimpling to a depth no greater than316 in. 5 mm. Intermittent open indications in a line, spacedless than14 in. 6 mm apart, shall be considered continuousor as one indication.7.1.2.3 Open indications18 in. 3 mm to 112 in. 35 mmlong, with the exception of those referr
24、ed to in 7.1.2.1, shall bedepressed 0.003 to 0.010 in. 0.05 to 0.25 mm below thesurface but need not be removed.7.1.2.4 Open indications less than18 in. 3 mm long neednot be depressed, dimpled, or removed.7.1.2.5 A cluster of open indications, with the exception ofthose referred to in 7.1.2.1, havin
25、g a total length not exceeding212 in. 65 mm in any 1 by 1-in. 25 by 25-mm square areaMetric Equivalents38 in. = 10 mm58 in. = 16 mmFIG. 1 Critical Surface Areas of Crankpin and Main Bearing JournalA 456/A 456M 99 (2003)2of bearing surface shall be depressed 0.003 to 0.010 in. 0.05to 0.25 mm below th
26、e surface but need not be removed. Whenthe total length exceeds 212 in. 65 mm, the indications areto be removed by dimpling to a depth no greater than316 in.5 mm.7.1.2.6 Non-open indications are acceptable.7.1.2.7 The total area of dimples in any journal or crankpinshall not exceed 1 % of the total
27、minor critical area of thecrankpin or main journal concerned.7.1.3 Number of DimplesThe number of dimples percrankshaft, excluding dimples in the areas defined in 6.1.3,shall not exceed the sum of the number of the crankpins andmain journals, nor five per crankpin or main journal.7.2 Class 2:7.2.1 M
28、ajor Critical Areas:7.2.1.1 Open indications other than pinpoints are not per-mitted and must be removed by dimpling to a depth no greaterthan316 in. 5 mm. Pinpoint indications are permissible, ifthere are no more than three in any14 by14-in. 6 by 6-mmsquare area. Pinpoints in excess of three must b
29、e dimpled to adepth of316 in. 5 mm and reduced to no more than threepinpoints unless they are removed at a lesser depth. If no morethan three pinpoints remain at the316-in. 5-mm depth, theyare acceptable and need not be removed.7.2.1.2 Magnetic particle buildup exceeding14 in. 6 mmin length and whic
30、h has been found to be non-open by theprocedure described in 3.2.1 shall be jointly investigated by themanufacturer and purchaser, or their representatives. Eachindication, or, with the concurrence of the purchaser, selectedrepresentative indications, shall be explored to a depth of atleast 0.003 in
31、. 0.05 mm, but not exceeding 0.010 in. 0.25mm. If open indications are found (3.2.1), then the require-ments of 7.2.1.1 shall apply. If open indications are not found,then the indications are acceptable and any explored area shallbe suitable radiused and classed as a depressed area rather thana dimp
32、le. If the presence of subsurface discontinuities is to beinvestigated, then Test Method A 275/A 275M shall be in-cluded in such an investigation. However, caution should beexercised in demagnetizing the crankshaft on completion ofthis examination.7.2.1.3 The total area of dimples shall be less than
33、 10 % ofthe total major critical area of the crankpin or journal con-cerned. The areas referred to in 6.1.3 shall be excluded fromthe total area allowable.7.2.2 Minor Critical Areas:7.2.2.1 Open indications oriented at an angle in excess of30 to the longitudinal axis must be removed at a depth notex
34、ceeding316 in. 5 mm, by dimpling.7.2.2.2 Open indications longer than 1 in. 25 mm indi-vidually or more than 2 in. 50 mm of total length per bearingjournal, that are parallel to the longitudinal axis within 30,must be removed by dimpling to a depth no greater than316 in.5 mm. Intermittent open indic
35、ations in a line, spaced less than14 in. 6 mm apart, shall be considered continuous or as oneindication.7.2.2.3 Open indications18 to 1 in. 3 to 25 mm long, withthe exception of those referred to in 7.2.2.1, shall be depressed0.003 to 0.010 in. 0.05 to 0.25 mm below the surface but neednot be remove
36、d.7.2.2.4 Open indications less than18 in. 3 mm long neednot be depressed, dimpled, or removed.7.2.2.5 A cluster of open indications, with the exception ofthose referred to in 7.2.2.1, having a total length not exceeding112 in. 35 mm in any 1 by 1-in. 25 by 25-mm square areaof bearing surface, shall
37、 be depressed 0.003 to 0.010 in. 0.05to 0.25 mm below the surface but need not be removed. Whenthe total length exceeds 112 in. 35 mm, the indications areto be removed by dimpling to a depth no greater than316 in.5 mm.7.2.2.6 Non-open indications are acceptable.(1)58 in. 16 mm on pin or journal,(2)F
38、illet radius, R,(3)Thrust collar, and(4)38 in. 10-mm ring beyond thrust collar.NOTE 1The critical area is 120 degrees on the pin or journal.FIG. 2 Reference Dimensions for CalculationsA 456/A 456M 99 (2003)37.2.2.7 The total area of dimples in any journal or crankpinshall not exceed 1 % of the total
39、 minor critical area of thecrankpin or main journal concerned.7.2.3 Number of DimplesThe number of dimples percrankshaft, excluding dimples in the areas defined in 6.1.3,shall not exceed the sum of the number of the crankpins andmain journals, nor five per crankpin or main journal.7.3 Class 3:7.3.1
40、Major Critical AreasSee 7.2.1.7.3.2 Minor Critical Areas:7.3.2.1 Open indications oriented at an angle in excess of30 to the longitudinal axis must be removed at a depth notexceeding316 in. 5 mm, by dimpling.7.3.2.2 Open indications longer than18 in. 3 mm that areparallel to the longitudinal axis wi
41、thin 30 must be removed bydimpling to a depth no greater than316 in. 5 mm.Intermittent open indications in a line, spaced less than14 in.6 mm apart, shall be considered continuous or as oneindication.7.3.2.3 Open indications (except pinpoint indications)18in. 3 mm or less in length, with the excepti
42、on of thosereferred to in 7.3.2.1, shall be depressed 0.003 to 0.010 in.0.05 to 0.25 mm, below the surface, but need not be removed.7.3.2.4 Non-open indications are acceptable.7.3.2.5 The total areas of dimples in any journal or crankpinshall not exceed 1 % of the total minor critical area of thecra
43、nkpin of main journal concerned.8. Dimpling and Depressing8.1 To dimple means to stone or grind to remove stock in anarea that contains an open indication. All dimples shall have abottom radius of approximately three times the dimple depthand should be smoothly blended to the surface area with afini
44、sh equal to the adjacent bearing surface.8.2 To depress is to flatten or relieve the edges of anindication with a fine pointed abrasive stone with the restrictionthat the depth beneath the original surface shall be 0.003 in.0.05 mm minimum to 0.010 in. 0.25 mm maximum and thatthe depressions be blen
45、ded into the bearing surface. A de-pressed area is not considered a dimple and is made only toprevent galling of the bearings.9. Inspection9.1 The manufacturer shall afford the purchasers inspectorall reasonable facilities necessary to satisfy him that thematerial is being produced and furnished in
46、accordance withthis specification. All tests and inspections shall be made at theplace of manufacture, unless otherwise agreed to, and shall notinterfere unnecessarily with the manufacturers operations.9.2 Upon agreement with the purchaser or if expressed inthe order or if shown on the drawing, the
47、manufacturer of thecrankshaft shall certify that the crankshaft was tested and is inaccordance with this specification.10. Product Marking10.1 The purchaser of the crankshaft shall provide themanufacturer with any marking or stamping identificationrequired.11. Keywords11.1 acceptance criteria; crank
48、shaft forgings; magnetic par-ticle examination; nondestructive examinationSUPPLEMENTARY REQUIREMENTSThe following supplementary requirements shall apply only when specified by the purchaser in thecontract or order.S1. Use of Direct Current MagnetizationS1.1 The magnetic particle examination of the c
49、rankshaftshall be done in accordance with Test Method A 275/A 275M.S2. Use of Magnetic LeechesS2.1 Magnetic leeches shall be applied only to noncriticalsurfaces of the crankshaft, as designated in the crankshaftdrawing, or as permitted by the purchaser.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this stand
