1、Designation:B41809 Designation: B418 12Standard 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 revis
2、ion. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () 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 gal
3、vanic zinc anodes used for the cathodic protection of more noble metals andalloys in sea water, brackish water, other saline electrolytes, or other corrosive environments.1.2 Type I anodes are most commonly used for such applications. The Type I anode composition in this specification meets thechemi
4、cal composition requirements of MIL-A-18001K.1.3 Zinc anodes conforming to this specification may be used in other waters, electrolytes, backfills, and soils where experiencehas shown that the specified composition is efficient and reliable. Type II anodes are most commonly used for such application
5、s.1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information only and are not considered standard.1.5 This standard does not purport to address all of the safety concerns, if any,
6、 associated with its use. It is the responsibilityof the user of this standard to become familiar with all hazards including those identified in the appropriate Material Safety DataSheet (MSDS) for this product/material as provided by the manufacturer, to establish appropriate safety and health prac
7、tices, anddetermine the applicability of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2B6 Specification for ZincB899 Terminology Relating to Non-ferrous Metals and AlloysB949 Specification for General Requirements for Zinc and Zinc Alloy ProductsE29 Practice for Usin
8、g Significant Digits in Test Data to Determine Conformance with SpecificationsE527 Practice for Numbering Metals and Alloys in the Unified Numbering System (UNS)E536 Test Methods for Chemical Analysis of Zinc and Zinc Alloys2.2 Military Standard:3MIL-A-18001K w/INT. AMENDMENT 3, 24 October 2007 Mili
9、tary Specification Anodes Sacrificial Zinc Alloy2.3 ISO Standards:4ISO 3815-1 Zinc and zinc alloys Part 1: Analysis of solid samples by optical emission spectrometryISO 3815-2 Zinc and zinc alloys Part 2: Analysis by inductively coupled plasma optical emission spectrometry3. Terminology3.1 Terms sha
10、ll be defined in accordance with Terminology B899.3.2 Definitions of Terms Specific to This Standard:3.2.1 cathodic protection, nreduction of corrosion by making the protected metal the cathode in a conducting medium byapplying direct current.3.2.2 galvanic anode, na metal electrode that sacrificial
11、ly corrodes when coupled to a more noble metal in a conductingmedium, and thereby supplies a protective electric current to the noble electrode.3.2.3 ribbon anode, na long, continuous sacrificial anode shape, with a diamond, square, rectangular, oval, or othercross-section, most commonly made of zin
12、c, magnesium or aluminum, having a core wire normally made of steel, that is usually1This specification is under the jurisdiction of ASTM Committee B02 on Nonferrous Metals and Alloys and is the direct responsibility of Subcommittee B02.04 on Zincand Cadmium.Current edition approved Oct.May 1, 2009.
13、2012. Published October 2009.July 2012. Originally approved in 1964. Last previous edition approved in 20082009 asB418 089. DOI: 10.1520/B0418-09.10.1520/B0418-12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Boo
14、k of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3Available from Standardization Documents Order Desk, DODSSP, Bldg. 4, Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http:/www.dodssp.daps.mil.4Available from American National Standar
15、ds Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.1This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible t
16、o adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standard.Copyrigh
17、t ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.supplied in coils or reels of 100 to 3600 ft depending upon size and cross-section.3.2.4 saline electrolyte, na solution consisting of mainly the chlorides of the alkali metals.4. Ordering Infor
18、mation4.1Orders for anodes under this specification shall include the following information:4.1.1ASTM designation and year of issue,4.1.2Type of anode material (see4.1 Orders for zinc anodes under this specification shall include information as specified in Specification B949, Section 4.:4.2 Additio
19、nal ordering information specific to this standard is as follows:4.2.1 Type of anode material (see Table 1),4.1.3Quantity in pounds,4.1.4Number of anodes,4.1.5Size of anode and whether contains rod insert and if so, type of insert and whether contains bolt hole and if so, whetherthreaded.4.1.6Whethe
20、r marking for identification is required including the marking patterns, if required, and4.1.7Whether certification is required.4.2.2 Number of anodes,4.2.3 Size of anode and whether contains rod insert and if so, type of insert and whether contains bolt hole and if so, whetherthreaded.5. Chemical C
21、omposition Chemical Requirements5.1 The anode shall be made from Special High Grade zinc conforming to Specification B6, with suitable alloying additionsfor Type I anodes. Composition of the anode alloy content shall conform to the limits prescribed in Table 1.5.2 Evidence from laboratory tests show
22、s that Type I composition may suffer intergranular corrosion. Susceptibility tointergranular corrosion increases with increasing temperature and is particularly severe above approximately 120F (50C).Intergranular corrosion can be avoided (at temperatures above about 120F) with Type II composition, w
23、hich must be made fromspecial high-grade zinc with an iron content well below the 0.003 % maximum given in Specification B6.5.3 Chemical requirement procedures shall be in compliance with the provisions of Specification B949, Section 5.2.6. Methods of Chemical Analysis6.1The chemical compositions en
24、umerated in this specification shall, in case of disagreement, preferably be determined bymethods mutually agreed upon or the methods listed in Sampling for Chemical Analysis6.1 The sample for chemical analysis shall be taken as follows:6.1.1 Selection of PortionAnumber of anodes shall be selected a
25、t random to give a representative sample of the lot.Alot shallconsist of not more than 20 000 lb (9070 kg) of zinc anodes cast from a single melt or not more than 5000 lb (2268 kg) of anodescast in a single 24-h period from more than one melt. The minimum number of anodes to be sampled shall be as s
26、pecified in Table2.6.1.2 Taking Sample for Chemical AnalysisEach selected anode shall be sampled by drilling or machining with a nonferroustool. The use of a drill with a tungsten carbide tip is recommended. The tool bit or drill shall not penetrate into the core materialor a cored anode. The cuttin
27、gs from all anodes in a lot shall be thoroughly mixed to form a uniform sample of not less than 50g total.6.1.3 Other sampling procedures shall be in compliance with the provisions of Specification B949, Section 6.7. Methods of Chemical Analysis7.1 The chemical compositions enumerated in this specif
28、ication shall, in case of disagreement, preferably be determined bymethods mutually agreed upon or the methods listed in Table 3 (note: spectrochemical methods may include ISO 3815-1,ISO 3815-2) approved for referee purposes by ASTM. Test Methods E536 shall be used, except for Type II.7.Bolt Holes a
29、nd Threads7.1For anodes with integral inserts intended for attachment by bolting, it is recommended that a bolt-hole spacing of 6 in. (152mm) or even multiples thereof be used.TABLE 1 Chemical RequirementsAType (UNS)BAluminum, % Cadmium, %Iron,max,%Lead,max,%Copper,max,%Others,Total,%ZincC,%Type I (
30、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 calculated valueobtained fro
31、m 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 E527.CDetermined arithmetically by difference.B418
32、1227.2Anodes with projecting rod inserts threaded for attachment by means of a bolted connection shall have Unified NationalCoarse threads.NOTE 1Test Methods E536 is directly applicable, in an unmodified form, only to alloys 3, 5, and 7. ISO 3815-1 and ISO 3815-2 are generic methodsapplied to zinc a
33、nd zinc alloys. Each of the methods may be modified and formatted for the alloy to be assayed. An experienced chemist, using suitableand/or traceable standards along with valid quality assurance techniques, will be able to perform and validate the methods and demonstrate acceptableprecision and accu
34、racy.8. Bolt Holes and Threads8.1 For anodes with integral inserts intended for attachment by bolting, it is recommended that a bolt-hole spacing of 6 in. (152mm) or even multiples thereof be used.8.2 Anodes with projecting rod inserts threaded for attachment by means of a bolted connection shall ha
35、ve Unified NationalCoarse threads.9. Workmanship, Finish, and Appearance8.1The9.1 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 exceeding14 the depth of the anode or 1 in. (2
36、5.4 mm), whichever is smallerwhen measured from a straightedge placed diagonally across opposite edges of the anode. Drill holes and saw cuts for samplingshall not be cause for rejection unless they are severe enough to cause premature failure of the anode.9.Sampling9.1The sample for chemical analys
37、is shall be taken as follows:9.1.1Selection of PortionA number of anodes shall be selected at random to give a representative sample of the lot. A lot shallconsist of not more than 20000 lb (9070 kg) of zinc anodes cast from a single melt or not more than 5000 lb (2268 kg) of anodescast in a single
38、24-h period from more than one melt. The minimum number of anodes to be sampled shall be as specified in Table3.9.1.2Taking Sample for Chemical AnalysisEach selected anode shall be sampled by drilling or machining with a nonferroustool. The use of a drill with a tungsten carbide tip is recommended.
39、The tool bit or drill shall not penetrate into the core materialor a cored anode. The cuttings from all anodes in a lot shall be thoroughly mixed to form a uniform sample of not less than 50g total.10. Claims10.1Claims to be considered shall be made in writing to the manufacturer within 30 days of r
40、eceipt of anodes at the purchasersplant and the results of the purchasers tests shall be given. The manufacturer shall be given one week from date of receipt of suchclaim to investigate his records and then shall agree either to satisfy the claim or send a representative to the plant of the purchase
41、r.Rejection and Rehearing10.1 Claims to be considered in accordance with the provisions of Specification B949, Section 8.11. Investigation of Claims11.1The inspector representing the manufacturer shall examine all pieces where physical defects are claimed. If agreement isnot reached, the question of
42、 fact shall be submitted to a mutually agreeable umpire, whose decision shall be final.11.2On a question of chemical analysis, a sample shall be taken by the representatives of both the manufacturer and thepurchaser as described in Section 4. The properly mixed and quartered sample shall be separate
43、d into three parts, each of whichshall be placed in a sealed envelope, one for the manufacturer, one for the purchaser, and one for the umpire if necessary. Themanufacturer and the purchaser shall each make an analysis, and if the results do not establish or dismiss the claim to theTABLE 3 2 Minimum
44、 Number of Anodes in SampleNumber of Anodes in LotMinimum Number ofAnodes in Sample1to500 2500 to 1000 3Each additional 1000 or part thereof 1TABLE 2 3 Methods of AnalysisMethodASTMDesignationSpectrochemical AnalysisChemical AnalysisChemical Analysis Test Methods E536B418 123satisfaction of both par
45、ties, the third sample shall be submitted to a mutually agreeable umpire, who shall determine the questionof quality, and whose determination shall be final. Investigation of Claim11.1 Claims shall be investigated in accordance with the provisions of Specification B949, Section 8.12. Rejection and R
46、ehearing12.1The expenses of the manufacturers representative and of the umpire shall be paid by the loser or divided in proportion tothe concession in case of compromise. In case of rejection being established, damages shall be limited to the payment by themanufacturer of freight both ways for repla
47、cement of the rejected anodes with anodes conforming to this specification. Settlementof Claims12.1 Claims shall be settled in accordance with the provisions of Specification B949, Section 8.13. Product Marking13.1A manufacturers identifying brand shall be cast, stamped, or displayed on at least one
48、 surface of each anode or packageof anodes. Product Identification Marking and Packaging13.1 Each slab, block, jumbo or ingot shall be marked for identification in accordance with the provisions of Specification B949,Section 10.14. Keywords14.1 cathodic protection; galvanic anodes; zinc; zinc anodes
49、SUMMARY OF CHANGESCommittee B02 has identified the location of selected changes to this standard since the last issue (B418 - 089)that may impact the use of this standard. (Approved OctoberMay 1, 2009.) 2012.)(1)Updated MIL specification revision J to revision K and revised title.Committee B02 has identified the location of selected changes to this standard since the last issue (B418-06)that may impact the use of this standard. (Approved November 1, 2008.) ) Revisions have been made to Sections2, 4, 6, 9, 10, 11, 12, and 13 to reference Specification B949
