1、BSI Standards PublicationBS ISO 13520:2015Determination of ferritecontent in austenitic stainlesssteel castingsBS ISO 13520:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 13520:2015.The UK participation in its preparation was entrusted to TechnicalCommitt
2、ee ISE/111, Steel Castings and Forgings.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Ins
3、titution 2015.Published by BSI Standards Limited 2015ISBN 978 0 580 76500 1ICS 77.140.80Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 October 2015.Amendments/
4、corrigenda issued since publicationDate T e x t a f f e c t e dBS ISO 13520:2015 ISO 2015Determination of ferrite content in austenitic stainless steel castingsDtermination du taux de ferrite des pices moules en acier inoxydable austnitiqueINTERNATIONAL STANDARDISO13520Second edition2015-10-01Refere
5、nce numberISO 13520:2015(E)BS ISO 13520:2015ISO 13520:2015(E)ii ISO 2015 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2015, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means,
6、 electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 V
7、ernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 13520:2015ISO 13520:2015(E)Foreword iv1 Scope . 12 Normative references 13 Terms and definitions . 14 Significance effects of ferrite content . 15 Methods of determination of ferrite content 25.1 Ch
8、emical composition method 25.2 Magnetic response method 25.3 Metallographic examination 26 Ordering information 27 General caution 28 Estimation of ferrite 39 Acceptance standards . 310 Certification . 3Annex A (normative) Determination of ferrite content by magnetic or metallographic means 4Annex B
9、 (informative) Notes to Schoefer diagram . 5 ISO 2015 All rights reserved iiiContents PageBS ISO 13520:2015ISO 13520:2015(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International
10、 Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, a
11、lso take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1.
12、 In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).Attention is drawn to the possibility that some of the eleme
13、nts of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received
14、 (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adheren
15、ce to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationThe committee responsible for this document is ISO/TC 017, TC Steel, Subcommittee SC 11, SC Steel castings.This second edition cancels and replaces the first edition (ISO 1352
16、0:2002), which has been technically revised.iv ISO 2015 All rights reservedBS ISO 13520:2015INTERNATIONAL STANDARD ISO 13520:2015(E)Determination of ferrite content in austenitic stainless steel castings1 ScopeProcedures are covered for estimating ferrite content in certain grades of austenitic iron
17、-chromium-nickel alloy castings that have compositions balanced to create the formation of ferrite as a second phase in amounts controlled within specified limits. Methods are described for estimating ferrite content by chemical, magnetic and metallographic means.2 Normative referencesThe following
18、documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 4990, Steel castin
19、gs General technical delivery requirementsISO 9042, Steels Manual point counting method for statistically estimating the volume fraction of a constituent with a point gridASTM A799, Standard Practice for Steel Castings, Stainless, Instrument Calibration, for Estimating Ferrite ContentBNIF 345, Evalu
20、ation de la teneur en ferrite dans les aciers inoxydables mouls austnitiques3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.3.1ferriteferromagnetic, body-centred cubic microstructural constituent of variable chemical composition in iron-chromium-ni
21、ckel alloysNote 1 to entry: Ferrite includes both delta and alpha species.3.2ferrite contentproportion of total volume of an iron-chromium-nickel alloy present as the ferrite phase3.3ferrite percentageferrite content expressed as a volume percent4 Significance effects of ferrite contentThe tensile a
22、nd impact properties, the weldability, and the corrosion resistance of iron-chromium-nickel alloy castings may be influenced beneficially or detrimentally by the ratio of the amount of ferrite to the amount of austenite in the microstructure. The ferrite content may be limited by purchase order requ
23、irements or by the design construction codes governing the equipment in which castings will be used. The quantity of ferrite in the structure is fundamentally a function of the chemical composition of the alloy and its thermal history. Because of segregation, the chemical composition and, therefore,
24、 the ferrite content, may differ from point to point on a casting. Determination of the ferrite content by ISO 2015 All rights reserved 1BS ISO 13520:2015ISO 13520:2015(E)any of the procedures described in Clause 5 is subject to varying degrees of imprecision which shall be recognized in setting rea
25、listic limits on the range of ferrite content specified. Sources of error are described in 5.1 to 5.3.5 Methods of determination of ferrite content5.1 Chemical composition methodDeviations from the actual content of each element present in an alloy because of chemical analysis variance, although pos
26、sibly minor in each case, can result in substantial difference in the ratio of total ferrite-promoting to total austenite-promoting elements. Therefore the precision of the ferrite content estimated from chemical composition depends on the accuracy of the chemical analysis procedure.The estimation o
27、f ferrite percent by means of the chemical composition offers the most useful and most common method of ferrite control during melting of the metal.5.2 Magnetic response methodPhases other than ferrite and austenite may be formed at certain temperatures and persist at room temperature. Contamination
28、 from other ferromagnetic materials may also occur. These may so alter the magnetic response of the alloy that the indicated ferrite content is quite different from that of the same chemical composition that has undergone different thermal treatment. Also, because the magnets or probes of the variou
29、s measuring instruments are small, different degrees of surface roughness or surface curvature will vary the magnetic linkage with the material being measured.5.3 Metallographic examinationMetallographic point count estimates of ferrite percentage may vary with the etching technique used for the ide
30、ntification of the ferrite phase and with the number of grid points chosen for examination, see A.2.For most accurate local estimate of ferrite percent, a quantitative metallographic method shall be used.6 Ordering informationOrders for material to this practice shall include the following as requir
31、ed.a) Applicable ISO product specification or other document covering product requirements.b) Alloy grade.c) Required ferrite range, in volume percent, of the casting after final heat treatment.d) Supplementary requirements, if any, desired.e) The method to be used for the determination of the ferri
32、te content and the location of measurements; whether on test blocks or on the castings shall be agreed between the customer and manufacturer.f) If measurements are to be carried out on the castings, the location of the measurements shall be agreed between the purchaser and the manufacturer. In the a
33、bsence of specification by the purchaser, the location may be chosen by the manufacturer.7 General caution7.1 In specifying ferrite content as required in 6 c) the purchaser shall not set limits that are in conflict with material specification requirements.2 ISO 2015 All rights reservedBS ISO 13520:
34、2015ISO 13520:2015(E)7.2 When setting ferrite content limits the purchaser shall ensure that the limits are compatible with the measurement method being used.8 Estimation of ferrite8.1 The ferrite content of the base metal of the casting can be estimated from the chemical composition in accordance w
35、ith the Schoefer diagram (see Figure B.1). For further information, see Annex B.If agreed at the time of ordering, the estimation can be carried out using an equivalent diagram as described in BNIF 3451)which allows ferrite evaluation (from 0 % to 30 %) in austenitic steel castings.8.1.1 The chemica
36、l analysis of the heat from which the castings are poured shall include the following elements whether or not required by the chemical requirements of the product specification: carbon, manganese, silicon, chromium, nickel, molybdenum, niobium, and nitrogen.8.1.2 The ferrite content of the casting s
37、hall be estimated from the central line of the diagram at the composition ratio of “chromium equivalent” (Cre) to “nickel equivalent” (Nie) determined from the following Formula (1):CrNieeCr 1,5Si1,4Mo Nb 4,99Ni 30C=()+()+()+()()+()+% %00,5Mn26N 0,02 2,77%()+(1)8.1.3 When a product analysis is made
38、by the purchaser, it shall include the elements listed in 8.1.1. If a comparison is made of ferrite estimated from a product analysis performed by the purchaser, with that estimated from the heat analysis (see 8.1.1), reference shall be made to check analyses in ISO 4990.8.2 Estimation of ferrite co
39、ntent in heat or product may be made by the magnetic response (see A.1) or metallographic (see A.2) methods on test blocks or castings respectively, if agreed by the purchaser and manufacturer.9 Acceptance standardsConformance with the required ferrite range specified in 6 c) as indicated by the est
40、imation procedure of 8.1 shall be the basis for acceptance of material supplied under this practice unless other methods of estimation are ordered as supplementary requirements, in which case the supplementary requirement shall be the basis of acceptance.10 Certification10.1 The manufacturers certif
41、ication shall be furnished to the purchaser stating that the material was sampled and tested in accordance with the specification (including year date) and was found to meet the requirements.10.2 The inspection document shall contain the results of the chemical analyses required by 8.1.1 and the ind
42、icated ferrite content range required. The estimates of ferrite content calculated in accordance with 8.1.2, and/or from magnetic measurements (A.1) and/or from point counts (A.2), if ordered by the purchaser, shall also be reported.10.3 The inspection document shall be signed by an authorized agent
43、 of the manufacturer.1) Published by Editions Techniques des Industries de la Fonderie, 44 avenue de la Division Leclerc, 92310 Svres, France. ISO 2015 All rights reserved 3BS ISO 13520:2015ISO 13520:2015(E)Annex A (normative) Determination of ferrite content by magnetic or metallographic meansA.1 E
44、stimation of ferrite content by measurement of magnetic responseA.1.1 GeneralThe ferrite content of the heat from which the castings are produced shall be estimated from measurements made by primary or secondary instruments, which have been properly calibrated for ferrite in castings (see ASTM A799
45、or BNIF 345). All measurements shall be made on material after the solution heat treatment required by the applicable product specification, or, if any subsequent solution heat treatment is employed, then after the final solution heat treatment.A.1.1.1 Measurements shall be made on the unstrained en
46、ds of tensile test specimens from the same heat as the castings represented. Measurements may be made either before or after performance of the tensile test. If a tensile test is not required by the applicable product specification, measurements may be made on a specimen cut from a test block as des
47、cribed in ISO 4990.A.1.1.2 Alternatively when specified, measurements shall be made on the base metal of the castings, in locations (not on weld deposits) designated on the design drawing or as otherwise agreed in writing between the purchaser and the manufacturer.A.1.2 Surface conditionA.1.2.1 The
48、instrument magnet or probe and the surface to be measured shall be cleaned and dried prior to testing in order to remove any scale, grease, lint, or dirt that could affect the accuracy of the measurement.A.1.2.2 Measurements shall be made more than 5 mm from the edge of a surface. When measurements
49、are made on a curved surface the radius of curvature shall be greater than 10 mm.A.1.3 Acceptance criteriaA.1.3.1 The average of the ferrite contents estimated from measurements in each designated location shall be within the limits stated in the order, and not more than 20 % of the individual measurements shall indicate ferrite contents less than or in excess of these limits.A.1.3.2 Should the requirements of A.1.3.1 not be met, an estimation of ferrite content may be made by the metallographic method described in A.2 and shall take p
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