1、Designation: A 319 71 (Reapproved 2006)Standard Specification forGray Iron Castings for Elevated Temperatures for Non-Pressure Containing Parts1This standard is issued under the fixed designation A 319; the number immediately following the designation indicates the year oforiginal adoption or, in th
2、e case of revision, the year of last 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. Scope1.1 This specification covers three classes of gray ironsuitable for castings exposed to
3、temperatures encountered insuch service as grate bars, stoker links, stoker parts, oil stillfurnace parts, firebox parts, ingot molds, glass molds, causticpots, and metal melting pots.NOTE 1This specification is general, covering cast irons normallyused for the above types of service, at temperature
4、s as high as 1400F(760C). It is not intended to imply that all three classes are suitablethroughout this entire temperature range without regard to actual servicestresses. Some are suitable for long service at the lower temperatures only,unless low stresses are involved.1.2 The three classes of gray
5、 iron covered by this specifi-cation are as follows:1.2.1 Class I, possessing superior resistance to thermalshock,1.2.2 Class II, possessing average resistance to thermalshock and a moderately good tensile strength (tensile strengthsabove 30 000 psi (207 MPa) may be expected), and1.2.3 Class III, po
6、ssessing a higher tensile strength thaneither Classes I or II (tensile strengths as high as 40 000 psi(276 MPa) may be expected).1.3 The values stated in inch-pound units are to be regardedas the standard.2. Referenced Documents2.1 ASTM Standards:2A 48/A 48M Specification for Gray Iron Castings3. Ma
7、nufacture3.1 The melting procedure shall be optional with thefoundry.4. Physical Requirements Physical Requirements4.1 Some of the gray cast irons described in this specifica-tion are deliberately made of a soft, low-strength iron forresistance to thermal shock, and strength requirements areunnecess
8、ary. For applications in which a strength requirementis essential, room temperature tensile strengths may be speci-fied up to those prescribed for Class 40 in Specification A 48.5. Machinability5.1 All machinable castings shall be limited in hardness atsuch locations on the castings as designated by
9、 the purchaser.The maximum hardness at the locations on castings that are tobe machined shall be a matter of agreement between themanufacturer and the purchaser.6. Chemical Composition6.1 It is the intention of this specification to classify theseirons in accordance with their carbon content equival
10、entcalculated as follows:Carbon content equivalent 5 C 1 0.3 Si 1 P! (1)where:C = carbon content, %,Si = silicon content, %, andP = phosphorus content, %,6.2 The carbon content equivalent and the minimum carboncontent for the various classes shall be as prescribed in Table 1.Table 2 prescribes the a
11、llowable silicon ranges predicated onthe basis of various permissible carbon contents. It is recom-mended that embrittling impurities be held to the followingmaximum limits:Phosphorus, max, %Sulfur, max, %0.600.151This specification is under the jurisdiction of ASTM Committee A04 on IronCastings and
12、 is the direct responsibility of SubcommitteeA04.01 on Gray and WhiteIron Castings.Current edition approved Oct. 1, 2006. Published October 2006. Originallyapproved in 1948. Last previous edition approved in 2001 as A 31971 (2001).2For referenced ASTM standards, visit the ASTM website, www.astm.org,
13、 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 Conshohocken, PA 19428-2959, United States.6.3 The three b
14、asic classes may be alloyed with chromium.When chromium is present as an alloying element, each classshall be subdivided into types designated as follows:Type Chromium, %A 0.200.40B 0.410.65C 0.660.95D 0.961.206.4 All irons may be alloyed to increase the strength and toimprove and stabilize the stru
15、cture for elevated-temperatureservice. The alloying elements, which, in addition to chro-mium, are commonly added to improve these properties, arecopper, molybdenum, nickel, and vanadium. Any combinationof these alloying elements that assists in resisting oxidation orsurface deterioration or in stab
16、ilizing the structure or retainingstrength at elevated temperatures, may be used.NOTE 2The provisions of this specification permit the purchaser toselect a grade of cast iron suitable for his service and to define the productas, for example:Castings Class II, Type B, plus |Cz|Cz alloys. All surfaces
17、 marked “f”(for finish) with HBN 250, max.7. Product Analysis7.1 When alloying elements are agreed upon between themanufacturer and the purchaser, the purchaser may make checkanalyses from any casting, test bar, or lot of castings deliveredunder this specification. Results of such analyses shall be
18、inaccordance with the limits agreed upon.8. Workmanship, Finish, and Appearance8.1 The castings shall conform substantially to the dimen-sions on drawings furnished by the purchaser or to thedimensions predicated by the pattern supplied by the purchaser,if no drawing has been provided. The castings
19、shall be freefrom injurious defects. Surfaces of the castings shall be freefrom burnt-on sand and shall be reasonably smooth. Runners,risers, fins, and other cast-on pieces shall be removed. In otherrespects the castings shall conform to whatever points may bespecially agreed upon between the manufa
20、cturer and thepurchaser.9. Inspection9.1 The inspector representing the purchaser shall have freeentry, at all times while work on the contract of the purchaseris being performed, to all parts of the manufacturers worksthat concern the manufacture of the material ordered. Themanufacturer shall affor
21、d the inspector, without charge, allreasonable facilities to satisfy him that the material is beingfurnished in accordance with this specification. All tests andinspection shall be made at the place of manufacture prior toshipment, unless otherwise specified, and shall be so conductedas not to inter
22、fere unnecessarily with the operation of theworks.10. Rejection10.1 Failure to meet the requirements of Section 7 or ofphysical tests, when required, shall be sufficient cause forrejection as defective castings.11. Certification11.1 Upon request of the purchaser, the manufacturer shallfurnish a stat
23、ement that the inspection and all of the tests havebeen made as specified; this statement shall contain the resultsof all specified tests.12. Keywords12.1 chemical composition; elevated temperature; grayiron; iron castings; non-pressure containing; tensile strengthASTM International takes no positio
24、n respecting the validity of any patent rights asserted 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.
25、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 withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM I
26、nternational Headquarters. Your comments will receive 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 sho
27、wn 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
28、-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).TABLE 1 Chemical RequirementsClass Carbon Content Equivalent Carbon, min, %I 3.814.40 3.50II 3.514.10 3.20III 3.203.80 2.80TABLE 2 Variations in Carbon and Silicon ContentsClass Carbon, % Silicon, %I 3.50 0.902.703.70 0.902.103.90 0.901.50II 3.20 0.902.703.40 0.902.103.50 1.80 maxIII 2.80 1.202.703.00 0.602.403.20 0.601.80A 319 71 (2006)2
