ASTM_A_1032_-_15.pdf

Designation:A103215Standard Test Method forHydrogen Embrittlement Resistance for Steel Wire Hard-Drawn Used for Prestressed Concrete Pipe1This standard is issued under the fixed designation A1032;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 parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This test method describes procedures to determine thehydrogen embrittlement(HE)resistance of hard-drawn steelwire used for prestressed 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-pound 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 determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2A648 Specification for Steel Wire,Hard-Drawn for Pre-stressed Concrete PipeD1193 Specification for Reagent Water3.Summary of Test Method3.1 Characterization of HE resistance of hard-drawn 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 tensile force,the solution temperature,andlength of time in the test are continuously monitored.4.Significance and Use4.1 Hard-drawn steel wire as used in prestressed 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 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 isinert 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 testspecimen 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 min.and capable of being stopped automatically onfracture of the specimen shall be used.5.3 Tensile Force FrameA closed stiff frame,in eitherhorizontal or vertical orientation,shall be used to position thetest cell such that a constant tensile force shall be applied to thetest specimen and maintained.The tensile force shall beapplied through use of a dead weight,or hydraulic loadingsystem 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 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 determination.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 responsibility of SubcommitteeA01.05 on Steel Reinforcement.Current edition approved May 1,2015.Published May 2015.Originallyapproved in 2004.Last previous edition approved in 2010 as A1032 04(2010).DOI:10.1520/A1032-15.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.*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 States1 6.3 Ammonium ThiocyanateNH4SCN solution 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 withSpecific