1、Designation: B 418 06Standard Specification forCast and Wrought Galvanic Zinc Anodes1This standard is issued under the fixed designation B 418; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in
2、parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 This specification covers cast and wrought galvanic zincanodes
3、 used for the cathodic protection of more noble metalsand alloys in sea water, brackish water, other saline electro-lytes, or other corrosive environments.1.2 Type I anodes are most commonly used for suchapplications. The Type I anode composition in this specifica-tion meets the chemical composition
4、 requirements of MIL-A-18001J.1.3 Zinc anodes conforming to this specification may beused in other waters, electrolytes, backfills, and soils whereexperience has shown that the specified composition is efficientand reliable. Type II anodes are most commonly used for suchapplications.1.4 The values s
5、tated in inch-pound units are to be regardedas the standard. The values given in parentheses are forinformation only.1.5 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 become familiarwith a
6、ll hazards including those identified in the appropriateMaterial Safety Data Sheet (MSDS) for this product/materialas provided by the manufacturer, to establish appropriatesafety and health practices, and determine the applicability ofregulatory limitations prior to use.2. Referenced Documents2.1 AS
7、TM Standards:B6 Specification for ZincB 899 Terminology Relating to Non-ferrous Metals andAlloysE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE 527 Practice for Numbering Metals and Alloys (UNS)E 536 Test Methods for ChemicalAnalysis of Zinc and Zi
8、ncAlloys2.2 Military Standard:MIL-A-18001J Military Specification Anodes, CorrosionPreventative, Zinc, Slab Disc, and Rod Shaped23. Terminology3.1 Terms shall be defined in accordance with TerminologyB 899.3.2 Definitions of Terms Specific to This Standard:3.2.1 cathodic protection, nreduction of co
9、rrosion bymaking the protected metal the cathode in a conductingmedium by applying direct current.3.2.2 galvanic anode, na metal electrode that sacrificiallycorrodes when coupled to a more noble metal in a conductingmedium, and thereby supplies a protective electric current tothe noble electrode.3.2
10、.3 ribbon anode, na long, continuous sacrificial anodeshape, with a diamond, square, rectangular, oval, or othercross-section, most commonly made of zinc, magnesium oraluminum, having a core wire normally made of steel, that isusually supplied in coils or reels of 100 to 3600 ft dependingupon size a
11、nd cross-section.3.2.4 saline electrolyte, na solution consisting of mainlythe chlorides of the alkali metals.4. Ordering Information4.1 Orders for anodes under this specification shall includethe following information:4.1.1 ASTM designation and year of issue,4.1.2 Type of anode material (see Table
12、1),4.1.3 Quantity in pounds,4.1.4 Number of anodes,4.1.5 Size of anode and whether contains rod insert and ifso, type of insert and whether contains bolt hole and if so,whether threaded.1This specification is under the jurisdiction of ASTM Committee B02 onNonferrous Metals and Alloys and is the dire
13、ct responsibility of SubcommitteeB02.04 on Zinc and Cadmium.Current edition approved Dec. 1, 2006. Published January 2007. Originallyapproved in 1964. Last previous edition approved in 2001 as B 418 01.2Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,Section D, 700 Robbins Ave.,
14、 Philadelphia, PA 19111-5098, http:/www.dodssp.daps.mil.1*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.4.1.6 Whether marking for identification is required includ-ing
15、 the marking patterns, if required, and4.1.7 Whether certification is required.5. Chemical Composition5.1 The anode shall be made from Special High Grade zincconforming to Specification B6, with suitable alloying addi-tions for Type I anodes. Composition of the anode alloy contentshall conform to th
16、e limits prescribed in Table 1.5.2 Evidence from laboratory tests shows that Type Icomposition may suffer intergranular corrosion. Susceptibilityto intergranular corrosion increases with increasing tempera-ture and is particularly severe above approximately 120F(50C). Intergranular corrosion can be
17、avoided (at tempera-tures above about 120F) with Type II composition, whichmust be made from special high-grade zinc with an ironcontent well below the 0.003 % maximum given in Specifica-tion B6.6. Methods of Chemical Analysis6.1 The chemical compositions enumerated in this specifi-cation shall, in
18、case of disagreement, be determined bymethods mutually agreed upon or the methods listed in Table 2approved for referee purposes by ASTM. Test Methods E 536shall be used, except for Type II.7. Bolt Holes and Threads7.1 For anodes with integral inserts intended for attachmentby bolting, it is recomme
19、nded that a bolt-hole spacing of 6 in.(152 mm) or even multiples thereof be used.7.2 Anodes with projecting rod inserts threaded for attach-ment by means of a bolted connection shall have UnifiedNational Coarse threads.8. Workmanship, Finish, and Appearance8.1 The zinc anodes shall be free of flash,
20、 burrs, cracks,blow holes, and surface slag, consistent with good commercialpractice. Cast anodes shall not have shrinkage cavities exceed-ing14 the depth of the anode or 1 in. (25.4 mm), whichever issmaller when measured from a straightedge placed diagonallyacross opposite edges of the anode. Drill
21、 holes and saw cuts forsampling shall not be cause for rejection unless they are severeenough to cause premature failure of the anode.9. Sampling9.1 The sample for chemical analysis shall be taken asfollows:9.1.1 Selection of PortionA number of anodes shall beselected at random to give a representat
22、ive sample of the lot. Alot shall consist of not more than 20 000 lb (9070 kg) of zincanodes cast from a single melt or not more than 5000 lb (2268kg) of anodes cast in a single 24-h period from more than onemelt. The minimum number of anodes to be sampled shall beas specified in Table 3.9.1.2 Takin
23、g Sample for Chemical AnalysisEach selectedanode shall be sampled by drilling or machining with anonferrous tool. The use of a drill with a tungsten carbide tipis recommended. The tool bit or drill shall not penetrate intothe core material or a cored anode. The cuttings from all anodesin a lot shall
24、 be thoroughly mixed to form a uniform sample ofnot less than 50 g total.10. Claims10.1 Claims to be considered shall be made in writing to themanufacturer within 30 days of receipt of anodes at thepurchasers plant and the results of the purchasers tests shallbe given. The manufacturer shall be give
25、n one week from dateof receipt of such claim to investigate his records and then shallagree either to satisfy the claim or send a representative to theplant of the purchaser.11. Investigation of Claims11.1 The inspector representing the manufacturer shall ex-amine all pieces where physical defects a
26、re claimed. If agree-ment is not reached, the question of fact shall be submitted toa mutually agreeable umpire, whose decision shall be final.11.2 On a question of chemical analysis, a sample shall betaken by the representatives of both the manufacturer and thepurchaser as described in Section 4. T
27、he properly mixed andquartered sample shall be separated into three parts, each ofwhich shall be placed in a sealed envelope, one for themanufacturer, one for the purchaser, and one for the umpire ifTABLE 1 Chemical RequirementsAType (UNS)BAluminum, % Cadmium, %Iron,max,%Lead,max,%Copper,max,%Others
28、,Total,%ZincC,%Type I (Z32120) 0.10.5 0.0250.07 0.005 0.006 0.005 0.1 remainderType II (Z13000) 0.005 max 0.003 max 0.0014 0.003 0.002 . remainderAThe following applies to all specified limits in this table: For purposes of determining conformance with this specification, the observed value or calcu
29、lated valueobtained from analysis shall be rounded off to the nearest unit in the last right hand place of figures used in expressing the specified limit, in accordance with the roundingmethod of Practice E29.BUNS designations were established in accordance with Practice E 527.CDetermined arithmetic
30、ally by difference.TABLE 2 Methods of AnalysisMethodASTMDesignationSpectrochemical AnalysisChemical AnalysisChemical Analysis Test Methods E 536TABLE 3 Minimum Number of Anodes in SampleNumber of Anodes in LotMinimum Number ofAnodes in Sample1to500 2500 to 1000 3Each additional 1000 or part thereof
31、1B418062necessary. The manufacturer and the purchaser shall each makean analysis, and if the results do not establish or dismiss theclaim to the satisfaction of both parties, the third sample shallbe submitted to a mutually agreeable umpire, who shalldetermine the question of quality, and whose dete
32、rminationshall be final.12. Rejection and Rehearing12.1 The expenses of the manufacturers representative andof the umpire shall be paid by the loser or divided in proportionto the concession in case of compromise. In case of rejectionbeing established, damages shall be limited to the payment bythe m
33、anufacturer of freight both ways for replacement of therejected anodes with anodes conforming to this specification.13. Product Marking13.1 A manufacturers identifying brand shall be cast,stamped, or displayed on at least one surface of each anode orpackage of anodes.14. Keywords14.1 cathodic protec
34、tion; galvanic anodes; zinc; zinc anodesSUMMARY OF CHANGESCommittee B02 has identified the location of selected changes to this standard since the last issue (B 418 - 01)that may impact the use of this standard. (Approved December 1, 2006.)(1) The scope has been reworded to indicate the full scope o
35、fthis standard in the first sentence for greater clarity.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 determination of the validity of any such paten
36、t 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 or withdrawn. Your comments are invited eithe
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38、aring 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).B418063
