1、Designation: B418 16Standard Specification forCast and Wrought Galvanic Zinc Anodes1This standard is issued under the fixed designation B418; 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 pa
2、rentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This specification covers cast and wrought galvanic zincanodes used for the cathodic protection of more noble metalsand alloys in sea water, brack
3、ish water, other salineelectrolytes, 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 requirements of MIL-A-18001K.1.3 Zinc anodes conforming to this specification may beu
4、sed 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 stated in inch-pound units are to be regardedas standard. The values given in parenthes
5、es are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.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 all h
6、azards including those identified in the appropriateSafety Data Sheet (SDS) for this product/material as providedby the manufacturer, to establish appropriate safety and healthpractices, and determine the applicability of regulatory limi-tations prior to use.2. Referenced Documents2.1 ASTM Standards
7、:2B6 Specification for ZincB899 Terminology Relating to Non-ferrous Metals and Al-loysB949 Specification for General Requirements for Zinc andZinc Alloy ProductsE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE527 Practice for Numbering Metals and Al
8、loys in theUnified Numbering System (UNS)E536 Test Methods for Chemical Analysis of Zinc and ZincAlloys2.2 Military Standard:3MIL-A-18001K w/INT. AMENDMENT 3, 24 October2007 Military Specification Anodes Sacrificial Zinc Alloy2.3 ISO Standards:4ISO 3815-1 Zinc and zinc alloys Part 1: Analysis of sol
9、idsamples by optical emission spectrometryISO 3815-2 Zinc and zinc alloys Part 2: Analysis byinductively coupled plasma optical emission spectrometry3. Terminology3.1 Terms shall be defined in accordance with TerminologyB899.3.2 Definitions of Terms Specific to This Standard:3.2.1 cathodic protectio
10、n, nreduction of corrosion 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
11、noble electrode.3.2.3 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 d
12、ependingupon size and cross-section.3.2.4 saline electrolyte, na solution consisting of mainlythe chlorides of the alkali metals.1This specification is under the jurisdiction of ASTM Committee B02 onNonferrous Metals and Alloys and is the direct responsibility of SubcommitteeB02.04 on Zinc and Cadmi
13、um.Current edition approved May 1, 2016. Published July 2016. Originally approvedin 1964. Last previous edition approved in 2012 as B418 12. DOI: 10.1520/B0418-16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book
14、 of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from DLA Document Services, Building 4/D, 700 Robbins Ave.,Philadelphia, PA 19111-5094, http:/quicksearch.dla.mil.4Available from American National Standards Institute (ANSI), 25 W. 43rd
15、St.,4th Floor, New York, NY 10036, http:/www.ansi.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14. Ordering Information4.1 Orders for zinc anodes under this specif
16、ication shallinclude information as specified in Specification B949.4.2 Additional ordering information specific to this standardis as follows:4.2.1 Type of anode material (see Table 1),4.2.2 Number of anodes,4.2.3 Size of anode and whether contains rod insert and ifso, type of insert and whether co
17、ntains bolt hole and if so,whether threaded.5. Chemical Requirements5.1 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 the limits prescribed in Table 1.5.2
18、 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 avoided (at tempera-tures above ab
19、out 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 B6.5.3 Chemical requirement procedures shall be in compli-ance with the provisions of Specification B949.6. Sampling for Chemical Analysis6.1
20、The sample for chemical analysis shall be taken asfollows:6.1.1 Selection of PortionA number of anodes shall beselected at random to give a representative 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
21、) 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 2.6.1.2 Taking Sample for Chemical AnalysisEach selectedanode shall be sampled by drilling or machining with anonferrous tool. The use of a drill with a tungsten
22、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 be thoroughly mixed to form a uniform sample ofnot less than 50 g total.6.1.3 Other sampling procedures shall be in compliancewith the provisions of
23、 Specification B949.7. Methods of Chemical Analysis7.1 The chemical compositions enumerated in this specifi-cation shall, in case of disagreement, preferably be determinedby methods mutually agreed upon or the methods listed inTable 3 (note: spectrochemical methods may includeISO 3815-1, ISO 3815-2)
24、 approved for referee purposes byASTM. Test Methods E536 shall be used, except for Type II.NOTE 1Test Methods E536 is directly applicable, in an unmodifiedform, only to alloys 3, 5, and 7. ISO 3815-1 and ISO 3815-2 are genericmethods applied to zinc and zinc alloys. Each of the methods may bemodifie
25、d and formatted for the alloy to be assayed. An experiencedchemist, using suitable and/or traceable standards along with valid qualityassurance techniques, will be able to perform and validate the methodsand demonstrate acceptable precision and accuracy.8. Bolt Holes and Threads8.1 For anodes with i
26、ntegral inserts intended for attachmentby bolting, it is recommended that a bolt-hole spacing of 6 in.(152 mm) or even multiples thereof be used.8.2 Anodes with projecting rod inserts threaded for attach-ment by means of a bolted connection shall have UnifiedNational Coarse threads.9. Workmanship, F
27、inish, and Appearance9.1 The zinc anodes shall be free of flash, 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 straigh
28、tedge placed diagonallyacross opposite edges of the anode. Drill holes and saw cuts forsampling shall not be cause for rejection unless they are severeenough to cause premature failure of the anode.10. Rejection and Rehearing10.1 Claims to be considered in accordance with the provi-sions of Specific
29、ation B949.TABLE 1 Chemical RequirementsAType (UNS)BAluminum, % Cadmium, %Iron,max,%Lead,max,%Copper,max,%Others,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 li
30、mits in this table: For purposes of determining conformance with this specification, the observed value or calculated value obtainedfrom 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 rounding m
31、ethodof Practice E29.BUNS designations were established in accordance with Practice E527.CDetermined arithmetically by difference.TABLE 2 Minimum Number of Anodes in SampleNumber of Anodes in LotMinimum Number ofAnodes in Sample1to500 2500 to 1000 3Each additional 1000 or part thereof 1B418 16211. I
32、nvestigation of Claim11.1 Claims shall be investigated in accordance with theprovisions of Specification B949.12. Settlement of Claims12.1 Claims shall be settled in accordance with the provi-sions of Specification B949.13. Product Identification Marking and Packaging13.1 Each slab, block, jumbo or
33、ingot shall be marked foridentification in accordance with the provisions of Specifica-tion B949.14. Keywords14.1 cathodic protection; galvanic anodes; zinc; zinc anodesSUMMARY OF CHANGESCommittee B02 has identified the location of selected changes to this standard since the last issue (B41812)that
34、may impact the use of this standard. (Approved May 1, 2016.)(1) The references to specific sections in Specification B949were removed.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standa
35、rd 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 the responsible technical committee and must be reviewed every five years andif
36、 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 careful consideration at a meeting of theresponsible technical committee, whi
37、ch 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 International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,U
38、nited 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). 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:/ 3 Methods of AnalysisMethodASTMDesignationSpectrochemical AnalysisChemical AnalysisChemical Analysis Test Methods E536B418 163
