ASTM_C_832_-_00_2015.pdf

Designation:C83200(Reapproved 2015)Standard Test Method ofMeasuring Thermal Expansion and Creep of RefractoriesUnder Load1This standard is issued under the fixed designation C832;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 the procedure for measuring thelinear change of refractory specimens that are subjected tocompressive stress while being heated and while being held atelevated temperatures.1.2 This test method does not apply to materials whosestrength depends on pitch or carbonaceous bonds unlessappropriate atmospheric control is used(see 7.3).1.3 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand 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:2E691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 maximum dilationthe percent expansion where thethermal-expansion rate equals the creep-deformation rate.Itcan be used in estimating thermal-expansion relief when usedin conjunction with the temperature at maximum dilation.3.1.2 temperature at maximum dilationin addition to es-timating thermal-expansion relief,it can be used to rankproducts in terms of relative refractoriness.In general,thehigher the temperature at maximum dilation,the more refrac-tory the product and the better it is able to resist deformation atelevated temperatures.3.1.3 20 to 50 h creepthe percent deformation between the20 and 50 h can be used to rank products in terms of relativeload bearing capacity at a particular temperature.Relativerankings of various products may differ at different tempera-tures.4.Summary of Test Method4.1 Test specimens sawed from samples of refractory brickor from prefabricated samples of monolithic refractories areplaced in a furnace and subjected to a prescribed compressivestress.Sensors are positioned for continuously measuring thelinear change of the specimens parallel to the direction of thecompressive stress.The temperature and linear change of thespecimens are continuously recorded while heating the furnaceat a controlled rate for thermal expansion under load testing.The time and linear change of the specimens are also continu-ously recorded while at soak temperature for 20 to 50 h ofcreep testing.4.2 The user should be aware that other mechanisms,besides those related to creep,may be activated.This isespecially true as temperatures approach 1650C.When othermaterial responses are activated,such as corrosion,oxidation,sintering,etc.,strong caution should be exercised when inter-preting and identifying creep mechanisms.4.3 Since materials tend to exhibit faster creep rates duringthe initial stage of deformation,the user should be cautionedwhen extrapolating measured creep rates beyond the normal50 h test time.The material must be in the secondary creepstage in order to extrapolate to longer times.5.Significance and Use5.1 The thermal expansion under load and the 20 to 50 hcreep properties of a refractory are useful in characterizing theload bearing capacity of a refractory that is uniformly heated.Directly applicable examples are blast furnace stoves and glassfurnace checkers.1This test method is under the jurisdiction of ASTM Committee C08 onRefractories and is the direct responsibility of Subcommittee C08.01 on Strength.Current edition approved March 1,2015.Published May 2015.Originallyapproved in 1976.Last previous edition approved in 2010 as C832 00(2010).DOI:10.1520/C0832-00R15.2For 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 6.Interferences6.1 Chemical Interactions with Test EnvironmentThe testenvironment(vacuum,inert gas,ambient air,etc.),includingmoisture content(percent relative humidity),may have astrong influence on both creep strain rate and creep rupture life.In particular,refractories susceptible to slow crack growth oroxidation will be strongly influenced by the test environment.Testing should be conducted in environments that are eitherrepresentative of service conditions or inert to the ref