ASTM_G_2_-_G_2M_-_06_2011e1.pdf

Designation:G2/G2M06(Reapproved 2011)1Standard Test Method forCorrosion Testing of Products of Zirconium,Hafnium,andTheir Alloys in Water at 680F(360C)or in Steam at 750F(400C)1This standard is issued under the fixed designation G2/G2M;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.1NOTEEditorial corrections were made in Section 14.3.4.1 in October 2013.1.Scope1.1 This test method covers(1)the determination of massgain,and(2)the surface inspection of products of zirconium,hafnium,and their alloys when corrosion tested in water at680F 360C or in steam at 750F 400C.1.2 This test method is to be utilized in its entirety to theextent specified herein as a product acceptance test.1.3 This test method may be used on wrought products,castings,powder metallurgy products,and weld metals.1.4 Unless a single unit is used,for example corrosion massgain in mg/dm2,the values stated in either inch-pound or SIunits are to be regarded separately as standard.The valuesstated in each system are not exact equivalents;therefore eachsystem must be used independently of the other.SI valuescannot be mixed with inch-pound values.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 establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.For specificprecautionary statements,see Section 9.2.Referenced Documents2.1 ASTM Standards:2D888 Test Methods for Dissolved Oxygen in WaterE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with Specifications3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 control coupons,nzirconium alloy specimens ofknown performance used to monitor the validity of the test.3.1.2 etching,na process for removal of surface metal byaction of acids in water.3.1.3 Grade A water,npurified water having a pH of 5.0 to8.0 and an electrical resistivity of not less than 1.0 Mcm.3.1.4 Grade B water,nwater prepared with deionized ordemineralized water having a minimum electrical resistivity of0.5 Mcm.3.1.5 The stated values of pH and electrical resistivity are tobe met after the measured values are corrected to 77F 25C.3.1.6 high mass gain coupons,nzirconium alloy speci-mens that have been specially heat-treated to produce a massgain higher than the maximum specified as acceptable valueused for verifying the severity of the test.3.1.7 reagent grade,nthe grade of chemicals normallyused for analytical purposes.4.Summary of Test Method4.1 Specimens of zirconium,hafnium,or their alloys areexposed to high-pressure water or steam at elevated tempera-tures for 72 or 336 h.The corrosion is normally measured bythe gain in mass of the specimens and by the appearance of theoxide film on the specimen surfaces.In some instances,such asweld evaluation,mass gain measurements are either impracti-cal to make or not required.When so specified,appearance ofthe specimen shall be the sole criterion for acceptance.5.Significance and Use5.1 This test method is primarily used as an acceptance testfor products of zirconium,hafnium,and their alloys.Thisstandard has been widely used in the development of newalloys,heat treating practices,and for evaluation of weldingtechniques.1This test method is under the jurisdiction ofASTM Committee B10 on Reactiveand Refractory Metals and Alloys and is the direct responsibility of SubcommitteeB10.02 on Zirconium and Hafnium.Current edition approved Sept.1,2011.Published September 2011.Originallyapproved in 1967.Last previous edition approved in 2006 as G2/G2M 06.DOI:10.1520/G0002_G0002M-06R11E01.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.2 Specimens are normally tested after careful etching andrinsing.Specimens with as-manufactured surfaces may also betested without further surface removal.5.3 When tubing with a second material clad on the innersurface is to be tested,the inner cladding shall be removedprior to the test.6.Interferences6.1 Autoclave loads that have one or more specimensshowing gross oxidation may affect results on other specimensin the autoclave by contamination of the environment.7.Apparatus7.1 The apparatus consists of equipment for(1)etching thespecimens when required,(2)measuring the specimen surfacearea and mass,the water resistivity and pH,test temperatureand pressure,etch and rinse temperature,and(3)performingthe water or steam corrosio