1、Designation: A1032 04 (Reapproved 2010)Standard Test Method forHydrogen Embrittlement Resistance for Steel Wire HardDrawn Used for Prestressing Concrete Pipe1This standard is issued under the fixed designation A1032; the number immediately following the designation indicates the year oforiginal adop
2、tion or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method describes procedures to determine thehydrogen embrittle
3、ment (HE) resistance of hard drawn steelwire used for prestressing concrete pipe.1.2 HE resistance is reported as time-to-failure of specimenstested in a laboratory.1.3 The values stated in SI units are to be regarded asstandard. The values given in parentheses are mathematicalconversions to inch-po
4、und units that are provided for informa-tion only and are not considered standard.1.4 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 establish appro-priate safety and health practices and d
5、etermine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A648 Specification for Steel Wire, Hard Drawn for Pre-stressing Concrete PipeD1193 Specification for Reagent Water3. Summary of Test Method3.1 Characterization of HE resistance of hard-drawn
6、 steelwire is accomplished by determining the time-to-failure of awire specimen under a maintained constant tensile force, whileimmersed in a heated solution of ammonium thiocyanate(NH4SCN). The load, the solution temperature, and length oftime in the test are continuously monitored.4. Significance
7、and Use4.1 Hard-drawn steel wire as used in prestressing concretepipe may be exposed to elemental hydrogen favorable tohydrogen induced embrittlement and cracking. Resistance tohydrogen embrittlement is necessary for prestressing wire toprovide long-term performance to installed pipe.4.2 The length
8、of time that a stressed wire specimen resistsfailure while exposed to a heated solution of NH4SCN, is anindication of the specimens resistance to hydrogen embrittle-ment.5. Apparatus5.1 Test CellThe test cell shall contain the test solutionand the wire specimen and be constructed of material which i
9、sinert to NH4SCN (as shown in Fig. 1). The test cell shall becylindrical with an inside diameter sufficient to provide aminimum of 5 mL of solution per 100 mm2(2 in.3per in.2)ofwire specimen surface area in contact with the solution. Thetest cell length shall allow the exposure of a minimum testsamp
10、le length of 150 mm (6 in.) to the test solution. The testcell shall be so designed that the wire specimen passes throughit and is sufficiently exposed outside the end of the cell as toallow application of a tensile force to the specimen.5.2 ChronometerA chronometer with a precision of atleast 6 1 m
11、in. and capable of being stopped automatically onfracture of the sample shall be used.5.3 Tensile Force FrameA closed stiff frame, in eitherhorizontal or vertical orientation, shall be employed to positionthe test cell such that a constant tensile force shall be appliedto the test specimen and maint
12、ained. The tensile force shall beaccomplished through use of a dead weight, or hydraulicloading system equipped with a force indicator.6. Reagents and Materials6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents conform
13、 to the specifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available. Other grades may be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe deter
14、mination.6.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water as definedby Type 4 of Specification D1193.1This test method is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibili
15、ty of SubcommitteeA01.05 on Steel Reinforcement.Current edition approved May 1, 2010. Published July 2010. Originally approvedin 2004. Last previous edition approved in 2004 as A1032 04. DOI: 10.1520/A1032-04R10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Cus
16、tomer 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 Ammonium ThiocyanateNH4SCN sol
17、ution shall beprepared by dissolving 250 g of NH4SCN (98.5 % pure) per1.0 L (0.52 lb of NH4SCN per 1.0 qt) of water.7. Sampling, Test Specimens, and Test Units7.1 Hard-Drawn Steel WireThe wire shall comply withSpecification A648.7.2 A test unit shall consist of 1500 mm (60 in.), or suchlength as spe
18、cified by the testing laboratory, of wire from a coilof wire. Specimens shall be identified with size, class, rod heatnumber, manufactured wire coil number, and name of wire androd manufacturer.7.2.1 The mechanical properties shall have been determinedin accordance with applicable sections of Specif
19、ication A648and a certified mill test report for the test unit shall be provided.7.3 Test SpecimenA test specimen shall be cut from thewire test unit, of such length that a minimum length of 150 mm(6 in.) will be exposed to the test solution, plus sufficient lengthto connect to a tension loading dev
20、ice. The test specimen shallbe identified as required in 7.2.7.3.1 The test specimen shall be cleaned by wiping with asoft cloth and degreased in acetone, or in trichlorethylene, thendried in air.7.3.2 To prevent false negative results, the test specimenmay be coated with an insulating material such
21、 as varnish, upto 25 mm (1 in.) into the test cell at each end. The 25 mmlength of coating at each end within the cell shall not beconsidered part of the length required in 7.3.8. Procedure8.1 PreparationPlace the test specimen into the emptytest cell and seal the ends of the cell. Place the test ce
22、ll into thetensile force frame.8.2 Load ApplicationApply a tensile force to the wirespecimen until 70 % of the Specification A648 minimumtensile strength for the wire diameter and class being tested isdeveloped. Maintain the tensile force to within 6 2.0 % for theduration of the test. The tensile lo
23、ad application shall becompleted within 5 min of loading initiation.8.3 Fill Test CellUpon completion of tensile force appli-cation, fill the test cell with NH4SCN test solution, preheated toa temperature of 50 6 1C (122 6 2F). Filling of the test cellshall be completed within 1 minute.8.4 Tensile L
24、oad and TemperatureThe tensile force andthe solution temperature shall be monitored and maintainedwithin the load requirements of 8.2 and the temperaturerequirements of 8.3, for the duration of the test.8.5 Time to FailureWith a full test cell, set the chronom-eter to zero and record time to failure
25、 to the nearest 1 min.Terminate test after 100 h of exposure if failure has notoccurred.9. Report9.1 Report ContentsA report of the HE tests for eachspecimen tested shall be made and shall include:9.1.1 Date of test and date of report.9.1.2 Identification of the test specimen.9.1.3 Wire diameter and
26、 class.9.1.4 Manufacturer of wire and manufacturer of rod.9.1.5 Wire coil number and rod heat number.9.1.6 Mechanical properties determined in accordance withSpecification A648.9.1.7 Chemical composition in accordance with Specifica-tion A648.9.1.8 Number of hours-to-failure, or number of hours to t
27、esttermination.9.1.9 Description of the actual test fabrication and testingprocedures.10. Precision and Bias10.1 PrecisionNo statement is made on the precision ofthis test method since the test results indicate only whetherthere is conformance to given criteria and no generallyaccepted method for de
28、termining precision of this test methodFIG. 1 Test CellA1032 04 (2010)2is currently available. General guidelines provided herein forthe specimens, instrumentation, and procedures make theresults intractable to calculation of meaningful values bystatistical analysis for precision at this time.10.2 B
29、iasSince there is no accepted reference materialsuitable for determining the bias in this test method, nostatement on bias is made.11. Keywords11.1 cracking; hydrogen embrittlement; prestressed con-crete pipe; prestressing; steel wireASTM International takes no position respecting the validity of an
30、y 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.This standard is subject to rev
31、ision 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 International Headquarters. Your
32、 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 shown below.This standard is copyr
33、ighted 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).A1032 04 (2010)3
