ASTM_D_522_-_D_522M_-_13.pdf

Designation:D522/D522M13Standard Test Methods forMandrel Bend Test of Attached Organic Coatings1This standard is issued under the fixed designation D522/D522M;the number immediately following the designation indicates the yearof original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 These test methods cover the determination of theresistance to cracking(flexibility)of attached organic coatingson substrates of sheet metal or rubber-type materials.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.1.3 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:2D823 Practices for Producing Films of Uniform Thicknessof Paint,Varnish,and Related Products on Test PanelsD1005 Test Method for Measurement of Dry-Film Thick-ness of Organic Coatings Using MicrometersD7091 Practice for Nondestructive Measurement of DryFilm Thickness of Nonmagnetic Coatings Applied toFerrous Metals and Nonmagnetic,Nonconductive Coat-ings Applied to Non-Ferrous Metals3.Summary of Test Method3.1 The coating materials under test are applied at uniformthickness to panels of sheet metal or rubber-type materials.After drying or curing the coated panels are bent over amandrel and the resistance to cracking of the coating isdetermined.In Test Method A the coated panels are bent overa conical mandrel.In Test Method B the coated panels are bentover cylindrical mandrels of various diameters.4.Significance and Use4.1 Coatings attached to substrates are elongated when thesubstrates are bent during the manufacture of articles or whenthe articles are abused in service.These test methods have beenuseful in rating attached coatings for their ability to resistcracking when elongated.They have been useful in evaluatingthe flexibility of coatings on flexible substrates.5.Test Specimen5.1 Substrates:5.1.1 If the purpose of the test is to determine the percent ofelongation of the coating material,the substrate shall becold-rolled steel strip 0.8 mm 132in.(22 gage)thick.5.1.2 If the purpose of the test is to rate the coated materialfor resistance to cracking,the substrate may be any type ofsheet metal or rubber-type material(for example,steel,aluminum,tinplate,or synthetic rubber).The thickness of thesheet metal may be less than 0.8 mm 132in.and the thicknessof the rubber-type materials may be as great as 13 mm 12in.5.1.3 The recommended panel size is 100 mm 4 in.inwidth and 150 mm 6 in.in length.The maximum size that theconical mandrel can accommodate is 115 mm 412in.wideand 190 mm 712in.long.5.1.4 The surface preparation of the substrate shall beagreed upon between the purchaser and the seller.Prior to theapplication of the coating,round slightly the edges of metalpanels to remove burrs in order to eliminate anomalous edgeeffects.NOTE1If elongations are to be determined for coatings applied tosubstrates other than 0.8 mm 132in.thick cold-rolled steel,they must bemeasured with a special mandrel jig as described in Appendix X1.2.5.2 Coated Panels:5.2.1 Apply uniform coatings of the materials under test tothe substrates in accordance with Practices D823 and air dry orbake under conditions mutually agreeable to the purchaser andthe seller.If percent elongation is to be measured,a minimumthickness of 25.4 m 1.0 mil is required on 0.8 mm 132in.1These test methods are under the jurisdiction of ASTM Committee D01 onPaint and Related Coatings,Materials,and Applications and are the directresponsibility of Subcommittee D01.23 on Physical Properties of Applied PaintFilms.Current edition approved Nov.1,2013.Published December 2013.Originallyapproved in 1939.Last previous edition approved in 2008 as D522 93a(2008).DOI:10.1520/D0522_D0522M-13.2For 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 thick cold-rolled steel.Perform a minimum of three determi-nations of coating thickness on each of the specimens inaccordance with Test Methods D1005 or D7091.5.2.2 From precoated sheets cut at least three specimens ofthe size g