ASTM_G_142_-_98_2011.pdf

Designation:G14298(Reapproved 2011)Standard Test Method forDetermination of Susceptibility of Metals to Embrittlement inHydrogen Containing Environments at High Pressure,HighTemperature,or Both1This standard is issued under the fixed designation G142;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.Scope1.1 This test method covers a procedure for determinationof tensile properties of metals in high pressure or hightemperature,or both,gaseous hydrogen-containing environ-ments.It includes accommodations for the testing of eithersmooth or notched specimens.1.2 This test method applies to all materials and productforms including,but not restricted to,wrought and castmaterials.1.3 The values stated in SI units are to be regarded asstandard.The values given in parentheses are for informationonly.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:2D1193 Specification for Reagent WaterE4 Practices for Force Verification of Testing MachinesE8 Test Methods for Tension Testing of Metallic MaterialsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodG15 Terminology Relating to Corrosion and Corrosion Test-ing(Withdrawn 2010)3G111 Guide for Corrosion Tests in High Temperature orHigh Pressure Environment,or BothG129 Practice for Slow Strain Rate Testing to Evaluate theSusceptibility of Metallic Materials to EnvironmentallyAssisted Cracking2.2 Military Standard:4MIL-P-27201B Propellant,Hydrogen3.Terminology3.1 Definitions:3.1.1 control test,na mechanical test conducted in anenvironment that does not produce embrittlement of a testmaterial.3.1.2 hydrogen embrittlement,nhydrogen induced crack-ing or severe loss of ductility caused by the presence ofhydrogen in the metal.3.1.3 Other definitions and terminology related to testingcan be found in Terminology G15.4.Summary of Test Method4.1 Specimens of selected materials are exposed to a gas-eous hydrogen containing environment at high pressure or hightemperature,or both,while being pulled to failure in uniaxialtension.The susceptibility to hydrogen embrittlement is evalu-ated through the determination of standard mechanical prop-erties in tension(that is,yield strength,ultimate tensilestrength,notched tensile strength,reduction in area or elonga-tion,or both).Comparison of these mechanical propertiesdetermined in a hydrogen-containing environment to thosedetermined in a non-embrittling environment(control test)provides a general index of susceptibility to cracking versus thematerials normal mechanical behavior.5.Significance and Use5.1 This test method provides a reliable prediction of theresistance or susceptibility,or both,to loss of material strengthand ductility as a result of exposure to hydrogen-containinggaseous environments.This test method is applicable over a1This test method is under the jurisdiction of ASTM Committee G01 onCorrosion of Metals and is the direct responsibility of Subcommittee G01.06 onEnvironmentally Assisted Cracking.Current edition approved March 1,2011.Published April 2011.Originallyapproved in 1996.Last previous edition approved in 2004 as G14298(2004).DOI:10.1520/G0142-98R11.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from Standardization Documents Order Desk,DODSSP,Bldg.4,Section D,700 Robbins Ave.,Philadelphia,PA 19111-5098Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 broad range of pressures,temperatures,and gaseous environ-ments.The results from this test method can be used toevaluate the effects of material composition,processing,andheat treatment as well as the effects of changes in environmentcomposition,temperature,and pressure.These results may ormay not correlate with service experience for particular appli-cations.Furthermore,this test method may not be suitable forthe evaluation of high temperature hydrogen attack in steelsunless suitable exposure time at the test conditions has takenplace prior to the initiation of tensile testing to allow for thedevelopment of internal blistering,decarburization or cracking,or both.6.Apparatus6.1 Since this test method is intended to be conducted athigh pressures and may also involve high temperatures,the