ASTM_B_614_-_16.pdf

Designation:B61416Standard Practice forDescaling and Cleaning Zirconium and Zirconium AlloySurfaces1This standard is issued under the fixed designation B614;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 practice covers a cleaning and descaling procedureuseful to producers,users,and fabricators of zirconium andzirconium alloys for the removal of ordinary shop soils,oxides,and scales resulting from heat treatment operations and foreignsubstances present as surface contaminants.1.2 It is not intended that these procedures become manda-tory for removal of any of the indicated soils but rather serveas a guide when zirconium and zirconium alloys are beingprocessed in the wrought,cast,or fabricated form.1.3 It is the intent that these soils be removed prior tochemical milling,joining,plating,welding,fabrication,and inany situation where foreign substances interfere with thecorrosion resistance,stability,and quality of the finishedproduct.1.4 Unless a single unit is used,for example,solutionconcentrations in g/l,the values stated in either inch-pound orSI units 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 specific hazardstatements,see Sections 3 and 7.2.Referenced Documents2.1 NFPA Standard:NFPA 484 Standard for Combustible Metals23.Processing Soil Removal3.1 Grease,oil,and lubricants employed in machining,forming,and fabricating operations on zirconium and zirco-nium alloys should be removed by employing one of themethods or a combination of methods as listed:(1)alkaline oremulsion soak-type cleaners,(2)ultrasonic cleaning,(3)acetone,citrus based cleaners,or safety solvent immersionwashing or vapor degreasing,or(4)electrolytic alkalinecleaning system.In the electrolytic system,the work can beeither anodic or cathodic polarity provided voltage and currentdensity are controlled to avoid anodizing.Removal of thesesoils is recommended prior to heat treatment or application ofacid treatment designated in Section 5.When electrolyticsystems are employed,the voltage should be controlled toprevent the occurrence of spark discharge and subsequentpitting.The use of trichloroethylene is not prohibited and canbe used;however its use is hazardous enough to preclude it asa recommended solvent in this standard.Care must be exer-cised when using chemical solvents.There are hazards associ-ated with their use,such as flammability,carcinogenicity,andozone depletion(see 7.1.)4.Blast Cleaning4.1 Mechanical descaling methods such as sandblasting,shot blasting,and vapor blasting may be used to remove hotwork scales and lubricants from zirconium surfaces if followedby thorough conditioning and cleaning as described in Section5.4.2 Aluminum oxide,silicon carbide,silica sand,zirconsand,and steel grit are acceptable media for mechanicaldescaling.Periodic replacement of used media may be requiredto avoid excessive working of the metal surface by dullparticulate.4.3 Roughening of exposed surface areas may occur fromgrit or shot if cleaning of the entire surface is accomplished byblasting.Partial cleaning for preserving the surface finish is tobe preferred in conjunction with proper pickling procedures.4.4 Any abrasive or shot blast cleaning may induce residualcompressive stresses in the surface of the material or zirconiumstructure.Warpage may occur in sections that are subsequentlychemical milled or contour machined.1This practice is under the jurisdiction of ASTM Committee B10 on Reactiveand Refractory Metals and Alloys and is the direct responsibility of SubcommitteeB10.02 on Zirconium and Hafnium.Current edition approved May 1,2016.Published May 2016.Originallyapproved in 1977.Last previous edition approved in 2010 as B614 10.DOI:10.1520/B0614-16.2Available from National Fire Protection Association(NFPA),1 BatterymarchPark,Quincy,MA 02269,http:/www.nfpa.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.5 In most cases,blast cleaning is not intended to eliminatepickling procedures completely.However,there are caseswhere blast cleaning does not need to be followed by a picklingoperation.Abrasives may not remove surface layers contami-nated with interstitial elements such as carbon,oxygen,hydrogen,and nitrogen.When these elements are present inexcessive amounts,they are preferab