ASTM_G_32_-_16.pdf

Designation:G3216Standard Test Method forCavitation Erosion Using Vibratory Apparatus1This standard is issued under the fixed designation G32;the number immediately following the designation indicates the year of originaladoption or,in the case of revision,the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the production of cavitationdamage on the face of a specimen vibrated at high frequencywhile immersed in a liquid.The vibration induces the forma-tion and collapse of cavities in the liquid,and the collapsingcavities produce the damage to and erosion(material loss)ofthe specimen.1.2 Although the mechanism for generating fluid cavitationin this method differs from that occurring in flowing systemsand hydraulic machines(see 5.1),the nature of the materialdamage mechanism is believed to be basically similar.Themethod therefore offers a small-scale,relatively simple andcontrollable test that can be used to compare the cavitationerosion resistance of different materials,to study in detail thenature and progress of damage in a given material,orbyvarying some of the test conditionsto study the effect of testvariables on the damage produced.1.3 This test method specifies standard test conditionscovering the diameter,vibratory amplitude and frequency ofthe specimen,as well as the test liquid and its container.Itpermits deviations from some of these conditions if properlydocumented,that may be appropriate for some purposes.Itgives guidance on setting up a suitable apparatus and coverstest and reporting procedures and precautions to be taken.Italso specifies standard reference materials that must be used toverify the operation of the facility and to define the normalizederosion resistance of other test materials.1.4 A history of this test method is given in Appendix X4,followed by a comprehensive bibliography.1.5 The values stated in SI units are to be regarded asstandard.The inch-pound units given in parentheses are forinformation only.1.6 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 safetywarning information,see 6.1,10.3,and 10.6.1.2.Referenced Documents2.1 ASTM Standards:2A276 Specification for Stainless Steel Bars and ShapesB160 Specification for Nickel Rod and BarB211 Specification for Aluminum and Aluminum-AlloyRolled or Cold Finished Bar,Rod,and WireD1193 Specification for Reagent WaterE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE960 Specification for Laboratory Glass BeakersG40 Terminology Relating to Wear and ErosionG73 Test Method for Liquid Impingement Erosion UsingRotating ApparatusG117 Guide for Calculating and Reporting Measures ofPrecision Using Data from Interlaboratory Wear or Ero-sion TestsG119 Guide for Determining Synergism Between Wear andCorrosionG134 Test Method for Erosion of Solid Materials by Cavi-tating Liquid Jet3.Terminology3.1 Definitions:3.1.1 See Terminology G40 for definitions of terms relatingto cavitation erosion.For convenience,important definitionsfor this standard are listed below;some are slightly modifiedfrom Terminology G40 or not contained therein.3.1.2 average erosion rate,na less preferred term forcumulative erosion rate.3.1.3 cavitation,nthe formation and subsequent collapse,within a liquid,of cavities or bubbles that contain vapor or amixture of vapor and gas.3.1.3.1 DiscussionIn general,cavitation originates from alocal decrease in hydrostatic pressure in the liquid,produced1This test method is under the jurisdiction of ASTM Committee G02 on Wearand Erosion and is the direct responsibility of Subcommittee G02.10 on Erosion bySolids and Liquids.Current edition approved Feb.1,2016.Published March 2016.Originallyapproved in 1972.Last previous edition approved in 2010 as G32 10.DOI:10.1520/G0032-16.2For 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 by motion of the liquid(see flow cavitation)or of a solidboundary(see vibratory cavitation).It is distinguished in thisway from boiling,which originates from an increase in liquidtemperature.3.1.3.2 DiscussionThe term cavitation,by itself,shouldnot be used to denote the damage or erosion of a solid surfacethat can be caused by it;this effect of cavitation is termedcavitation damage or cavitation erosion.To erode a solidsu