1、BRITISH STANDARDBS EN ISO 7500-2:2006Metallic materials Verification of static uniaxial testing machines Part 2: Tension creep testing machines Verification of the applied forceThe European Standard EN ISO 7500-2:2006 has the status of a British StandardICS 77.040.10g49g50g3g38g50g51g60g44g49g42g3g5
2、8g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN ISO 7500-2:2006This British Standard was published under the authority of the Standards Policy and Strategy Committee on 28 Feb
3、ruary 2007 BSI 2007ISBN 978 0 580 50137 1National forewordThis British Standard was published by BSI. It is the UK implementation of EN ISO 7500-2:2006. It supersedes BS EN ISO 7500-2:1999 which is withdrawn.The UK participation in its preparation was entrusted by Technical Committee ISE/NFE/4, Mech
4、anical 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 corr
5、ect application.Compliance with a British Standard cannot confer immunity from legal obligations. Amendments issued since publicationAmd. No. Date CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 7500-2December 2006ICS 77.040.10 Supersedes EN ISO 7500-2:1999 English VersionMetallic mate
6、rials - Verification of static uniaxial testingmachines - Part 2: Tension creep testing machines - Verificationof the applied force (ISO 7500-2:2006)Matriaux mtalliques - Vrification des machines pouressais statiques uniaxiaux - Partie 2: Machines dessai defluage en traction - Vrification de la forc
7、e applique (ISO7500-2:2006)Metallische Werkstoffe - Prfung von statischeneinachsigen Prfmaschinen - Teil 2:Zeitstandprfmaschinen fr Zugbeanspruchung - Prfungund Kalibrierung des Kraftmesssystems (ISO 7500-2:2006)This European Standard was approved by CEN on 4 September 2006.CEN members are bound to
8、comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Central S
9、ecretariat or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the off
10、icialversions.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
11、, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2006 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Member
12、s.Ref. No. EN ISO 7500-2:2006: EForeword This document (EN ISO 7500-2:2006) has been prepared by Technical Committee ISO/TC 164 “Mechanical testing of metals“ in collaboration with Technical Committee ECISS/TC 1 “Steel - Mechanical testing“, the secretariat of which is held by AFNOR. This European S
13、tandard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by June 2007, and conflicting national standards shall be withdrawn at the latest by June 2007. This document supersedes EN ISO 7500-2:1999. According to the CEN/CENE
14、LEC 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, Malt
15、a, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Endorsement notice The text of ISO 7500-2:2006 has been approved by CEN as EN ISO 7500-2:2006 without any modifications. EN ISO 7500-2:2006Reference numberISO 7500-2:2006(E)INTERNATI
16、ONAL STANDARD ISO7500-2Second edition2006-12-15Metallic materials Verification of static uniaxial testing machines Part 2: Tension creep testing machines Verification of the applied force Matriaux mtalliques Vrification des machines pour essais statiques uniaxiaux Partie 2: Machines dessai de fluage
17、 en traction Vrification de la force applique EN ISO 7500-2:2006ii iiiContents Page Foreword iv 1 Scope . 1 2 Normative references . 1 3 Symbols and their meanings. 2 4 General inspection of the testing machine 2 5 Verification of the force applied by the testing machine 3 5.1 General. 3 5.2 Masses
18、. 3 5.3 Determination of the discrimination threshold 3 5.4 Determination of the lower limit of verification . 4 5.5 Test procedure 4 5.6 Assessment of the force applied by the machine . 6 6 Class of the testing machine . 6 6.1 General. 6 6.2 Lever-type creep testing machines. 6 6.3 Creep testing ma
19、chines with the force applied by direct acting masses . 7 6.4 Creep testing machines with the force applied directly by a spring. 7 7 Verification report. 8 8 Intervals between verifications . 8 Annex A (normative) General inspection of the testing machine . 9 EN ISO 7500-2:2006iv Foreword ISO (the
20、International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee
21、 has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnic
22、al standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bo
23、dies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying an
24、y or all such patent rights. ISO 7500-2 was prepared by Technical Committee ISO/TC 164, Mechanical testing of metals, Subcommittee SC 1, Uniaxial testing. This second edition cancels and replaces the first edition (ISO 7500-2:1996), which has been technically revised. ISO 7500 consists of the follow
25、ing parts, under the general title Metallic materials Verification of static uniaxial testing machines: Part 1: Tension/compression testing machines Verification and calibration of the force-measuring system Part 2: Tension creep testing machines Verification of the applied force EN ISO 7500-2:20061
26、Metallic materials Verification of static uniaxial testing machines Part 2: Tension creep testing machines Verification of the applied force 1 Scope This part of ISO 7500 specifies the verification of testing machines used for uniaxial creep testing in tension in accordance with ISO 204. The verific
27、ation consists of a general inspection of the testing machine, and a verification of the force applied by the testing machine. This part of ISO 7500 applies to dead-weight machines, lever-type creep testing machines and direct-spring-loading machines. Machines with a force-measuring system1)should b
28、e verified in accordance with ISO 7500-1, Metallic materials Verification of static uniaxial testing machines Part 1: Tension/compression testing machines Verification and calibration of the force-measuring system. 2 Normative references The following referenced documents are indispensable for the a
29、pplication 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. ISO 204, Metallic materials Uniaxial creep testing in tension Method of test ISO 376, Metallic materials Calibr
30、ation of force-proving instruments used for the verification of uniaxial testing machines 1) For the purposes of this part of ISO 7500, a force-measuring system comprises the load cell plus conditioning plus indicator. EN ISO 7500-2:20062 3 Symbols and their meanings For the purposes of this part of
31、 ISO 7500, the symbols in Table 1 apply. For the purposes of this part of ISO 7500 the following types of creep testing machines are recognized: dead-weight machines, with or without guides (Figures A.1 and A.2); overslung or underslung lever machines (Figures A.3, A.4 and A.5); jockey-weight machin
32、es, either with overslung or underslung lever (Figures A.6 and A.7); any combination of the types of machines mentioned above (Figure A.8); testing machines with force applied by a spring (Figure A.9). Table 1 Symbols and meaning Symbol Unit Meaning FNN Maximum force of the force range of the testin
33、g machine FiN Force applied to creep testing machine: for dead-weight machines: Fi= mgna for lever-type machines: Fi= mgnRa for jockey-weight machines, the value of Fiis indicated on the scale of the machine for spring-type machines: force applied to spring-calibration device F N True force indicate
34、d by the force-proving instrument F N Arithmetic mean of several measurements of F or Fiat the same discrete force Fmax, FminN Highest or lowest value of F or Fiat the same discrete force FMN Force applied by the masses on the scale pan of the machines FVN Lower limit of the verified force range R L
35、ever ratio used for the verification b % Relative repeatability error of the force-measuring system of the testing machine d N Discrimination threshold d1N Discrimination threshold corresponding to 20 % of the maximum force of the force range (FN) a % Relative discrimination threshold q % Relative a
36、ccuracy error of the force-measuring system of the testing machine agn= standard acceleration of free fall, in m/s2(gn= 9,806 65 m/s2). This quantity was earlier also called “standard acceleration due to gravity”. 4 General inspection of the testing machine The verification of the testing machine sh
37、all only be carried out if the machine is in good working order. For this purpose, a general inspection of the machine shall be carried out before verification of the force applied by the machine (see Annex A). EN ISO 7500-2:200635 Verification of the force applied by the testing machine 5.1 General
38、 This verification shall be carried out for each of the force ranges used. If the testing machine has several force ranges, each force range2)shall be regarded as a separate testing machine. This verification shall be carried out using tension-force-proving instruments. These instruments shall be in
39、 accordance with ISO 376. The class of the force-proving instrument shall be equal or superior to the class determined for the creep testing machine. 5.2 Masses The masses used to apply the forces during the verification can be either a) known masses with an accuracy equal to or better than 0,1 %, v
40、erified at least every five years, or b) masses dedicated for use with a given creep testing machine, applied in the same sequence as during the test. 5.3 Determination of the discrimination threshold The discrimination threshold (d) of the machine is defined as the smallest increment of force that
41、can be applied and detected during the verification procedure. The discrimination threshold (d) shall be determined at 20 %, 60 % and 100 % of the maximum force FNof the force range. If forces of a magnitude less than 0,2 FNare to be tested (see 5.2), the discrimination threshold shall additionally
42、be determined at the lower limit of the provided testing range. The discrimination threshold (d) is measured at the magnitude of the force resulting from the smallest mass added to, or removed from, the scale pan of the machine, or the force which corresponds to the smallest recordable movement of t
43、he jockey weight which causes a detectable change at the indicator of the force-proving instrument. The relative discrimination threshold (a) is calculated for each level of force specified according to the following formula : 100daF= (1) and shall remain within the limits given in Table 3 for the c
44、lass of machine considered. The discrimination threshold (d) shall be expressed in newtons. 2) Force range means, in the case of a deadweight machine, the range over which the machine is to be used; in the case of a lever-type machine it is the force range for each separate lever ratio. EN ISO 7500-
45、2:20064 5.4 Determination of the lower limit of verification The lower limit of verification (FV) shall be specified according to Table 2. Table 2 Lower limit of verification Class FV0,5 400 d11 200 d12 100 d1d1is the discrimination threshold corresponding to 20 % of the force-measuring range. NOTE
46、The lower limit of verification of the machine may be less than the permissible operating range of the equivalent-grade force-proving instrument used to determine the discrimination threshold at the 60 % and maximum force conditions. Consequently, to verify the testing machine precisely at the lower
47、 end of the range, it will be necessary to use two measuring instruments, one for the upper range and a second one having appropriate capacity for the extreme lower measuring range. 5.5 Test procedure 5.5.1 General Verification shall be carried out for each force range for which a grade is sought. V
48、erification shall not be performed below the lower limit FVfor any force range. 5.5.2 Alignment The force-proving device shall be mounted in the machine, with the self-alignment devices normally used included at each end of the loading train. 5.5.3 Balancing the lever 5.5.3.1 General It is necessary
49、 to balance the loading train to achieve a zero loading reading on the force-proving device when it is mounted in the loading train in place of the test piece. The precise method of balancing is dependent upon the design of the machine; however, in general the procedures described in 5.5.3.2 and 5.5.3.3 will be applicable. 5.5.3.2 Overslung lever The force-verification device shall be hung in the loading train in place of the test specimen, with the lower loading bar disconnected immediately
