【BS標(biāo)準(zhǔn)word原稿】BS EN 10325-2006 Steel. Determination of yield strength increase by the effect of heat treatment (Bake-Hardening-Index).doc

豆丁網(wǎng)：/kmust1licensed copy: sheffieldun sheffieldun, na, thu oct 26 04:40:51 gmt+00:00 2006, uncontrolled copy, (c) bsibritish standardbs en10325:2006steel determination of yield strength increase by the effect of heat treatmentbake-hardening-indexthe european standard en 10325:2006 has the status of a britishstandardics 77.040.10; 71.080.20 bs en 10325:2006national forewordthis british standard was published by bsi. it is the uk implementation ofen 10325:2006.the uk participation in its preparation was entrusted by technical committee ise/nfe/4, mechanical testing of metals, to subcommittee ise/nfe/4/1, uniaxial testing of metals.a list of organizations represented on ise/nfe/4/1 can be obtained on request to its secretary.this publication does not purport to include all the necessary provisions of a contract. users are responsible for its correct application.compliance with a british standard cannot confer immunity from legal obligations.licensed copy: sheffieldun sheffieldun, na, thu oct 26 04:40:51 gmt+00:00 2006, uncontrolled copy, (c) bsiamd. no.datecommentsthis british standard was published under the authority of the standards policy and strategy committeeon 29 september 2006 bsi 2006isbn 0 580 48971 xamendments issued since publicationeuropean standard norme europenneeuropische normen 10325august 2006ics 77.040.10; 71.080.20english versionsteel - determination of yield strength increase by the effect of heat treatment bake-hardening-indexaciers - dtermination de laugmentation de la limite apparente dlasticit due un traitement thermique (index de durcissement la cuisson bake-hardening)stahl - bestimmung der streckgrenzenerhhung durchwrmebehandlung (bake-hardening-index)this european standard was approved by cen on 7 july 2006.cen members are bound to comply with the cen/cenelec internal regulations which stipulate the conditions for giving this european standard the status of a national standard without any alteration. up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the central secretariat or to any cen member.this european standard exists in three official versions (english, french, german). a version in any other language made by translation under the responsibility of a cen member into its own language and notified to the central secretariat has the same status as the official versions.cen members are the national standards bodies of austria, belgium, cyprus, czech republic, denmark, estonia, finland, france, germany, greece, hungary, iceland, ireland, italy, latvia, lithuania, luxembourg, malta, netherlands, norway, poland, portugal, romania, slovakia, slovenia, spain, sweden, switzerland and united kingdom.european committee for standardization c o m i t eur o p en de nor m a l i s a ti on eur o p i s c h es kom i tee f r nor m ung management centre: rue de stassart, 36 b-1050 brusselslicensed copy: sheffieldun sheffieldun, na, thu oct 26 04:40:51 gmt+00:00 2006, uncontrolled copy, (c) bsi 2006 cenall rights of exploitation in any form and by any means reserved worldwide for cen national members.ref. no. en 10325:2006: een 10325:2006 (e)licensed copy: sheffieldun sheffieldun, na, thu oct 26 04:40:51 gmt+00:00 2006, uncontrolled copy, (c) bsicontentsforeword.31scope .42normative references .43terms and definitions .44symbols and designations .65principle .66test equipment .67test pieces .68testing procedure.68.1testing conditions .68.2heat treatment conditions .68.3determination of bake-hardening-index (bh2) .79test report .77licensed copy: sheffieldun sheffieldun, na, thu oct 26 04:40:51 gmt+00:00 2006, uncontrolled copy, (c) bsiforewordthis document (en 10325:2006) has been prepared by technical committee eciss/tc 1 “steel - mechanical testing”, the secretariat of which is held by afnor.this european standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by february 2007, and conflicting national standards shall be withdrawn at the latest by february 2007.according to the cen/cenelec internal regulations, the national standards organizations of the following countries are bound to implement this european standard: austria, belgium, cyprus, czech republic, denmark, estonia, finland, france, germany, greece, hungary, iceland, ireland, italy, latvia, lithuania, luxembourg, malta, netherlands, norway, poland, portugal, romania, slovakia, slovenia, spain, sweden, switzerland and united kingdom.licensed copy: sheffieldun sheffieldun, na, thu oct 26 04:40:51 gmt+00:00 2006, uncontrolled copy, (c) bsi1scopethis document specifies the method for the determination of yield strength increase by the effect of heat treatment(bake-hardening-index) for steel.notethis test is applied in particular, to steels showing a mechanism of bake hardening, which are specially intended for automotive industry.2normative referencesthe following referenced documents are indispensable for the application of this document. for dated references, only the edition cited applies. for undated references, the latest edition of the referenced document (including any amendments) applies.en 10002-1:2001, metallic materials tensile testing part 1: method of test at ambient temperature3terms and definitionsfor the purposes of this document, the terms and definitions given in en 10002-1:2001 and the following apply.notehowever it should be noted that in the context of this document, the term yield strength also covers 0,2 % proof strength in addition to its definition in en 10002-1.3.1 bake-hardening-index(bh2) increase of yield strength between a reference condition after a 2 % plastic pre-strain and the condition obtained after a heat treatment simulating the usual industrial paint processes (see figure 1)notethe heat treatment of simulation is specified in 8.2.licensed copy: sheffieldun sheffieldun, na, thu oct 26 04:40:51 gmt+00:00 2006, uncontrolled copy, (c) bsikey1stress2strain3application of a 2 % plastic pre-strain4tensile test after heat treatment on the same test piecefigure 1 illustration of the determination of bh2licensed copy: sheffieldun sheffieldun, na, thu oct 26 04:40:51 gmt+00:00 2006, uncontrolled copy, (c) bsi4symbols and designationsthe symbols used in this document and the corresponding designations are given in table 1.table 1 symbols and designationssymbolunitdesignationrp2,rmpa astress corresponding to a 2 % plastic prestrain measured on the test piecerel,tmpalower yield strength measured on the test piece initially prestrained at 2 % and then heat treatedrp0,2,tmpa0,2 % proof strength measured on the test piece initially prestrained at 2 % and then heat treatedbh2mpabake-hardening-indexa1 mpa = 1 n/mm.5principlethe test determines an index giving the increase of yield strength of a test piece submitted to a 2 % plastic pre- strain, then to a specified heat treatment.6test equipmentthe test equipment shall be in accordance with en 10002-1.7test piecesthe test pieces shall be according to en 10002-1.8testing procedure8.1testing conditionsthe tensile test shall be performed according to annex a of en 10002-1:2001. the testing rate given in en 10002-1 for the beginning of the tensile test, shall only be increased after the determination of rel or rp0,2. during the pre-straining of the test pieces, the testing rate shall be kept constant up to a plastic pre-strain of (2 0,05) %. all tensile tests used to characterize a steel shall be performed with the same actual testing rate.8.2heat treatment conditionsa test piece temperature of 170 c shall be achieved within 7 min. the heat treatment time of (20 0,5) min commences when a test piece temperature of 168 c is achieved. the heat treatment equipment used shall be capable of keeping the prescribed test piece temperature (i.e. 170 c) at 2 c. the temperature measuring device shall have a resolution of no more than 1 c with a maximum measuring uncertainty of 2 c. after the holding time, the test piece shall be air cooled to room temperature, i.e. (23 5) c.8.3determination of bake-hardening-index (bh2)the bh2-index is the difference between the proof strength, rp2,r, of the 2 % plastically strained test piece (modulus of elasticity of steel considered to be 200 000 mpa) and the lower yield strength, rel,t, or the proof strength, rp0,2,t, of the same test piece after an additional heat treatment at 170 c with a holding time of 20 minutes. determining rel,t or rp0,2,t after heat treatment, the cross-sectional area of the test piece after a plastic pre-strain shall be used.bh 2 = rel,t (or rp0,2t ) rp2,r(1)licensed copy: sheffieldun sheffieldun, na, thu oct 26 04:40:51 gmt+00:00 2006, uncontrolled copy, (c) bsi9test report9.1if testing of bh2 is carried out in combination with the conventional test according to en 10002-1, the bake- hardening-index shall be added to the test report.9.2if testing of bh2 is carried out separately, the test report shall contain at least the following information:a)reference to this european standard;b)identification of the test piece;c)location and direction of sampling;d)test result.licensed copy: sheffieldun sheffieldun, na, thu oct 26 04:40:51 gmt+00:00 2006, uncontrolled copy, (c) bsibs en10325:2006bsi389 chiswick high roadlondonw4 4albsi british standards institutionbsi is the independent national body responsible for preparingbritish standards. it presents the uk view on standards in europe and at the international level. it is incorporated by royal charter.revisionsbritish standards are updated by amendment or revision. users ofbritish standards should make sure that they possess the latest amendments or editions.it is the constant aim of bsi to improve the quality of our products and services. we would be grateful if anyone finding an inaccuracy or ambiguity while using this british standard would inform the secretary of the technical committee responsible, the identity of which can be found on the inside front cover.tel: +44 (0)20 8996 9000. fax: +44 (0)20 8996 7400.bsi offers members an individual updating service called plus which ensures that subscribers automatically receive the latest editions of standards.buying standardsorders for all bsi, international and foreign standards publications should be addressed to customer services. tel: +44 (0)20 8996 9001.fax: +44 (0)20 8996 7001. email: . standards are alsoavailable from the bsi website at .in response to orders for international standards, it is bsi policy to supply the bsi implementation of those that have been published as british standards, unless otherwise requested.information on standardsbsi provides a wide range of information on national, european and international standards through its library and its technical help to exporters service. various bsi electronic information services are also available which give details on all its products and services. contact the information centre.tel: +44 (0)20 8996 7111. fax: +44 (0)20 8996 7048. email: .subscribing members of bsi are kept up to date with standards developments and receive substantial discounts on the purchase price of standards. for details of these and other benefits co