ASTM A278 A278M-2001(2015) Standard Specification for Gray Iron Castings for Pressure-Containing Parts for Temperatures Up to 650° F (350° C)《温度高达650 ℉ (350 ℃) 的承压件灰铁铸件的标准规格》.pdf

《ASTM A278 A278M-2001(2015) Standard Specification for Gray Iron Castings for Pressure-Containing Parts for Temperatures Up to 650&deg F (350&deg C)《温度高达650 ℉ (350 ℃) 的承压件灰铁铸件的标准规格》.pdf》由会员分享，可在线阅读，更多相关《ASTM A278 A278M-2001(2015) Standard Specification for Gray Iron Castings for Pressure-Containing Parts for Temperatures Up to 650&deg F (350&deg C)《温度高达650 ℉ (350 ℃) 的承压件灰铁铸件的标准规格》.pdf（4页珍藏版）》请在麦多课文档分享上搜索。

1、Designation: A278/A278M 01 (Reapproved 2015)Standard Specification forGray Iron Castings for Pressure-Containing Parts forTemperatures Up to 650F (350C)1This standard is issued under the fixed designation A278/A278M; the number immediately following the designation indicates the yearof original adop

2、tion or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.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 Defens

3、e.1. Scope1.1 This specification2covers gray iron for castings suitablefor pressure-containing parts for use at temperatures up to650F (350C).1.2 Classes of Iron:1.2.1 Castings of all classes are suitable for use up to 450F(230C). For temperatures above 450F and up to 650F, onlyClass 40, 45, 50, 55,

4、 and 60 castings are suitable.1.2.2 Castings of all classes are suitable for use up to 230C.For temperatures above 230C and up to 350C, only Class275, 300, 325, 350, 380, and 415 castings are suitable.1.3 The values stated in either SI units or inch-pound unitsare to be regarded separately as standa

5、rd. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.2. Referenced Documents2.1 ASTM Standards:3A644 Terminology Relating to Iron CastingsE

6、8 Test Methods for Tension Testing of Metallic Materials3. Terminology3.1 Definitions of many terms common to gray iron castingsmay be found in Terminology A644.4. Classification4.1 Classification by tensile strength.4.1.1 Castings ordered to this specification are classifiedbased upon the minimum t

7、ensile strength of the iron in ksi, inEnglish units. Class 25 has a minimum specified tensilestrength of 25 ksi.4.1.2 Castings ordered to this specification are classifiedbased upon the minimum tensile strength of the iron in MPa, inMetric units. Class 150 has a minimum specified tensilestrength of

8、150 MPa.5. Ordering Information5.1 Orders for material in this specification should includethe following information:5.1.1 ASTM designation and year date,5.1.2 Class of iron required and service temperature,5.1.3 Quantity,5.1.4 Heat Treatment:5.1.4.1 Whether or not heat treatment is required for Cla

9、ss40, 45, 50, 55, and 60 castings to be used at temperatures at450F or less (see 6.2),5.1.4.2 Whether or not heat treatment is required for Class275, 300, 325, 350, 380, and 415 castings to be used attemperatures at 230C or less (see 6.2),5.1.5 The size of separately cast test bar to be poured (seeS

10、ection 9 and Table 1),5.1.6 The size of test specimen to be machined from testbarsCorS,and5.1.7 Special requirements.6. Materials and Manufacture6.1 Castings intended for use above 450F (230C) shall bestress-relieved by placing them in a suitable furnace at atemperature not exceeding 400F (200C) and

11、 heating themuniformly to the temperatures and for the times specified inTable 2. The heating and cooling rates shall be uniform andshall not be more than 400F/h (250C/h) for castings of 1-in.(25-mm) maximum section. For heavier sections the maximumheating and cooling rates in degrees Fahrenheit per

12、 hour shallbe 400 divided by the maximum section thickness.6.2 Heat Treatment and Cooling Rate:6.2.1 Castings of Class Nos. 45, 50, 55, and 60, which are tobe used at temperatures below 450F, may be heat treated in1This specification is under the jurisdiction of ASTM Committee A04 on IronCastings an

13、d is the direct responsibility of Subcommittee A04.01 on Grey and WhiteIron Castings.Current edition approved Nov. 1, 2015. Published November 2015. Originallyapproved in 1944. Last previous edition approved in 2011 as A278/A278M 01 (2011). DOI: 10.1520/A0278_A0278M-01R15.2For ASME Boiler and Pressu

14、re Vessel Code applications see related Specifi-cation SA-278 in Section II of that Code.3For referenced 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 Summ

15、ary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1accordance with 6.1 or they shall be cooled in the mold to500F at an average rate of not more than 100F/h for castingsup to 1 in. in section. For heavier sect

16、ions the maximumcooling rate in degrees Fahrenheit per hour shall be 100divided by the maximum section thickness.6.2.2 Castings of Class Nos. 275, 300, 325, 350, 380, and415, which are to be used at temperatures below 230C, may beheat treated in accordance with 6.1 or they shall be cooled inthe mold

17、 to 250C at an average rate of not more than 50C/hfor castings up to 25-mm in section. For heavier sections themaximum cooling rate in degrees Celsius per hour shall be1250 divided by the maximum section thickness.7. Chemical Composition7.1 Carbon Equivalent:7.1.1 Class 40, 45, 50, 55, and 60 castin

18、gs intended forservice above 450F (230C) shall have a maximum carbonequivalent of 3.8 % as calculated from the equation CE = %C+ 0.3 (%Si + %P). The maximum phosphorus and sulfurcontents shall be 0.25 % and 0.12 %, respectively.7.1.2 Class 275, 300, 325, 350, 380, and 415 castingsintended for servic

19、e above 230C shall have a maximumcarbon equivalent of 3.8 % as calculated from the equation CE= %C + 0.3 (%Si + %P). The maximum phosphorus and sulfurcontents shall be 0.25 % and 0.12 %, respectively.7.2 The chemical analysis for total carbon shall be made oneither chilled cast pencil-type specimens

20、 or thin wafers ap-proximately132 in. thick cut from test coupons. Drillings shallnot be used because of attendant loss of graphite.8. Tensile Requirements8.1 Iron used in supplying castings to this specification shallconform to the tensile requirements prescribed in Table 3 andTable 4.9. Test Bars9

21、.1 Separately cast test bars having the dimensions shown inTable 1 shall be poured from the same lot as the castingsrepresented. The size of the test bar to be poured shall beselected by the purchaser using Table 5. In the event no choiceis made, the selection will be made by the manufacturer.9.2 Se

22、parately cast test bars shall be heat treated in the samefurnace together with the castings represented.9.3 At the option of the manufacturer, test coupons may beremoved from the casting at a location agreed upon betweenthe manufacturer and purchaser.9.4 Castings weighing in excess of 2000 lb may be

23、 repre-sented either by separately cast test bars (9.1) or by integrallycast test bars having a cooling rate closely approximating thatof the controlling section of the casting.9.5 For castings weighing in excess of 10 000 lb or havinga controlling section greater than 2 in., test bars may beremoved

24、 from the casting or integral projections having a crosssection no less than the controlling section. The minimumtensile strength requirement for tension tests performed oneither of these test bars shall be 80 % of the specified class.10. Molding and Pouring Test Bars10.1 The test bars shall be cast

25、 in dried siliceous sand moldsmaintained at approximately room temperature. A suitabledesign for a mold is shown in Fig. 1.TABLE 1 Diameters and Lengths of Cast Test BarsTestBarAs-Cast Diameter, in. (mm) Length, in. (mm)Minimum(Bottom)Maximum(Top)Minimum(Specified)Maximum(Recommended)A 0.88 (23) 0.8

26、5 (22) 0.96 (25) 5.0 (125) 6.0 (1.50)B 1.20 (33) 1.14 (32) 1.32 (36) 7.0 (150) 9.0 (230)C 2.00 (54) 1.90 (53) 2.10 (58) 6.0 (175) 10.0 (255)SAAAll dimensions of Test Bar S shall be agreed upon by the manufacturer and thepurchaser.TABLE 2 Stress Relieving RequirementsClass Metal Temperature, F(C)Hold

27、ing Time, hA40, 45, 50, 55, 60 1050 to 1200 2 12(275, 300, 325, 350,380, 415)(565 to 650) (2 min)B(12 max)BAIn no case shall the holding time be less than 1 h/in. of maximum metal section,or in excess of 12 h max, dependent upon which governs.BIn no case shall the holding time be less than1hforevery

28、 25-mm metal section,or in excess of 12 h max, depending upon which governs.TABLE 3 Tensile RequirementsClass Tensile Strength,min, ksiNo. 20 20No. 25 25No. 30 30No. 35 35No. 40 40No. 45 45No. 50 50No. 55 55No. 60 60TABLE 4 Tensile Requirements (SI)Class Tensile Strength,min, MPaNo. 150 150No. 175 1

29、75No. 200 200No. 225 225No. 250 250No. 275 275No. 300 300No. 325 325No. 350 350No. 380 380No. 415 415TABLE 5 Separately Cast Test Bars for Use When a SpecificCorrelation Has Not Been Established Between the Test Bar andthe CastingThickness of the Wall of the ControllingSection of the Casting, in. (m

30、m)Test BarUnder 0.25 (6) S0.25 to 0.50 (6 to 12) A0.51 to 1.00 (13 to 25) B1.01 to 2 (26 to 50) COver 2 (50) SA278/A278M 01 (2015)211. Workmanship, Finish, and Appearance11.1 All castings shall be made in a workmanlike mannerand shall conform to the dimensions on drawings furnished bythe purchaser.

31、If the pattern is supplied by the purchaserwithout drawings, the dimensions of the casting shall be aspredicted by the pattern.11.2 The surface of the casting shall be free of adheringsand, scale, cracks, and hot tears as determined by visualexamination. Other surface discontinuities shall meet the

32、visualacceptance standards specified in the order.12. Sampling12.1 A lot shall consist of one of the following:12.1.1 All the metal poured from a single heating in a batchtype melting furnace,12.1.2 All the metal from two or more batch type meltingfurnaces poured into a single ladle or single castin

33、g, or12.1.3 All the metal poured from a continuous meltingfurnace for a given period of time between changes in charge,processing conditions, or aim-for chemistry or 4 h, whicheveris the shorter period.12.1.3.1 The purchaser may agree to extend the 4-h timeperiod to8hifthemanufacturer can demonstrat

34、e sufficientprocess control to warrant such an extension.13. Tension Test Specimens13.1 Tension test specimens A and B in Fig. 2 shall bemachined from test bars A and B in Table 1, respectively.13.2 The purchaser shall specify whether test specimen B orC is to be machined from test bar C. If no choi

35、ce is made, themanufacturer shall make the selection.13.3 The size of the test specimen to be machined from testbar S shall be as agreed upon between the manufacturer andpurchaser.14. Number of Tests and Retests14.1 One tension test shall be performed on each lot inaccordance with Test Method E8 and

36、 conform to the tensilerequirements specified.14.2 If the results of a valid test fail to conform to therequirements of this specification, two retests shall be made. Ifeither retest fails to meet the specification requirements, thecastings represented by these test specimens shall be rejected.14.3

37、If, after testing, a test specimen shows evidence of adefect, the results of the test may be invalidated and anothermade on a specimen from the same lot.15. Repair15.1 Any repairs performed on castings produced to thisspecification shall be agreed upon between the manufacturerand purchaser.16. Certi

38、fication16.1 When requested by the purchaser, the manufacturershall furnish his certification stating that the material wasmanufactured, sampled, tested, and inspected in accordancewith this specification including the year date. The certificationshall also include the results of all tests performed

39、.16.2 A signature is not required on the certification.However, the document shall clearly identify the organizationsubmitting the certification and the authorized agent of themanufacturer who certified the test results. Notwithstandingthe absence of a signature, the organization submitting thecerti

40、fication is responsible for its content.17. Inspection17.1 All tests and inspections required by this specificationshall be performed by the manufacturer or other reliablesources whose services have been contracted for by theNumber of test bars in a single mold-2 suggested. P2 in. (50-mm) suggestedL

41、see Table 1. N516 in. (8-mm) in diameter, suggestedDsee Table 1. M1.5 N, suggestedWnot less than diameter, D.FIG. 1 Suitable Design and Dimensions for Mold for Separately Cast Cylindrical Test Bars for Gray IronA278/A278M 01 (2015)3manufacturer. Complete records of all tests and inspectionsshall be

42、maintained by the manufacturer and shall be availablefor review by the purchaser.18. Rejection and Rehearing18.1 Castings which fail to conform to the requirementsspecified when inspected or tested by the purchaser or his agentmay be rejected. Rejection shall be reported to the manufac-turer or supp

43、lier promptly and in writing. In case of dissatis-faction with the test results, the manufacturer or supplier maymake claim for a rehearing.19. Product Marking19.1 Castings shall have the name of the manufacturer, orhis recognized trademark, and the class of iron to which itconforms, cast or indelib

44、ly stamped on a surface indicated bythe purchaser or in such a position as not to injure theusefulness of the casting.20. Keywords20.1 elevated temperature service; gray iron castings; pres-sure containing partsASTM International takes no position respecting the validity of any patent rights asserte

45、d 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 time by th

46、e 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 receive

47、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 Internat

48、ional, 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 t

49、he ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ in. (mm) Tension TestSpecimen ATension TestSpecimen BTension TestSpecimen CG Length of parallel, min 0.50 (13) 0.75 (20) 1.25 (32)D Diameter 0.500 0.010 (13 0.25) 0.750 0.015 (20 0.4) 1.25 0.025 (32 0.5)R Radius of fillet, min 1 (25) 1 (25) 2 (50)A Length of reduced section, min 114 (32) 112 (38) 214