1、ASD-STAN STANDARD NORME ASD-STAN ASD-STAN NORM ASD-STAN prEN 2951 Edition P 2 December 2017 PUBLISHED BY THE AEROSPACE AND DEFENCE INDUSTRIES ASSOCIATION OF EUROPE - STANDARDIZATION Rue Montoyer 10 - 1000 Brussels - Tel. 32 2 775 8126 - Fax. 32 2 775 8131 - www.asd-stan.org ICS: Supersedes edition P
2、 1 of November 1997 Descriptors: ENGLISH VERSION Aerospace series Metallic materials Test method Micrographic determination of content of non-metallic inclusions Luft- und Raumfahrt Metallische Werkstoffe Prfverfahren Mikrographische Bestimmung von nichtmetallischen Einschlssen Srie arospatiale Matr
3、iaux mtalliques Mthode dessai Dtermination par micrographie de la distribution dinclusions non-mtalliques This “Aerospace Series“ Prestandard has been drawn up under the responsibility of ASD-STAN (The AeroSpace and Defence Industries Association of Europe - Standardization). It is published for the
4、 needs of the European Aerospace Industry. It has been technically approved by the experts of the concerned Domain following member comments. Subsequent to the publication of this Prestandard, the technical content shall not be changed to an extent that interchangeability is affected, physically or
5、functionally, without re-identification of the standard. After examination and review by users and formal agreement of ASD-STAN, the ASD-STAN prEN will be submitted as a draft European Standard (prEN) to CEN (European Committee for Standardization) for formal vote and transformation to full European
6、 Standard (EN). The CEN national members have then to implement the EN at national level by giving the EN the status of a national standard and by withdrawing any national standards conflicting with the EN. ASD-STAN Technical Committee approves that: “This document is published by ASD-STAN for the n
7、eeds of the European Aerospace Industry. The use of this standard is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefrom, is the sole responsibility of the user.” ASD-STAN reviews each standard and technical report at
8、least every five years at which time it may be revised, reaffirmed, stabilized or cancelled. ASD-STAN invites you to send your written comments or any suggestions that may arise. All rights reserved. No parts of this publication may be reproduced, stored in a retrieval system or transmitted, in any
9、form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission of ASD-STAN. Order details: E-mail: salesasd-stan.org Web address: http:/www.asd-stan.org/ Edition approved for publication 1st December 2017 Comments should be sent within six month
10、s after the date of publication to ASD-STAN Material Domain Copyright 2017 ASD-STAN prEN 2951:2017 (E) 2 Contents Page Foreword 2 Introduction 3 1 Scope 3 2 Normative references 3 3 Terms and definitions . 3 4 Health and safety . 3 5 Test method 4 6 Classification of inclusions 4 7 Acceptance criter
11、ia . 4 Annex A (normative) Acceptance criteria Categories 6 A.1 Categories of acceptance 6 A.2 Example of the use of combined field ratings . 7 Annex B (informative) Standard evolution form 8 Foreword This standard was reviewed by the Domain Technical Coordinator of ASD-STANs Material Domain. After
12、inquiries and votes carried out in accordance with the rules of ASD-STAN defined in ASD-STANs General Process Manual, this standard has received approval for Publication. prEN 2951:2017 (E) 3 Introduction This standard is part of the series of EN metallic material standards for aerospace application
13、s. The general organization of this series is described in EN 4258. 1 Scope This standard specifies the general requirements for the micrographic determination of content of non-metallic inclusions of metallic materials for aerospace applications. It also gives tables of standard acceptance criteria
14、 for particular steel types. It shall be applied when referred to in the EN technical specification or material standard unless otherwise specified on the drawing, order or inspection schedule. This standard is mainly applicable to steel but may be used on other metallic materials. This standard is
15、not normally applicable to austenitic corrosion resisting steel, other than precipitation hardening, or to free-machining steel unless invoked in the material standards. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispens
16、able 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. EN 4258, Aerospace series Metallic materials General organization of standardization Links between types of EN sta
17、ndards and their use EN 4259, Aerospace series Metallic materials Definition of general terms 1) ASTM E45, Standard Test Methods for Determining the Inclusion Content of Steel 2) 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 4259 apply. 4 Health and
18、 safety Resources, test pieces, test samples, test materials, test equipments and test procedures shall comply with the current health and safety regulations/laws of the countries where the test is to be carried out. Where materials and/or reagents which may be hazardous to health are specified, app
19、ropriate precautions in conformity with local regulations and/or laws shall be taken. 1) Published as ASD-STAN Prestandard at the date of publication of this standard by AeroSpace and Defence industries Association of Europe - Standardization (ASD-STAN) (www.asd-stan.org) 2) Published by: ASTM Natio
20、nal (US) American Society for Testing and Materials http:/www.astm.org/ prEN 2951:2017 (E) 4 5 Test method Microscopical method A or method D of ASTM E45 is used. The method used depends on the melting route and/or the requirement of the material standard and shall be in accordance with Table 1. Tab
21、le 1 Selection of microscopical methods Melting route Method Air melted A Remelted (Vacuum and/or electroslag) A or D Sampling, test specimen geometry and preparation of specimens shall be according to ASTM E45. 6 Classification of inclusions See Table 2. Table 2 Inclusion types Inclusion types A Su
22、lphides B Aluminates C Silicates D Globular oxides Each inclusion type is classified in two groups of picture series based on the thickness of the inclusions: thin, heavy. Method A: Counting shall be carried out on the worst field according to Method A of ASTM E45 standard over a surface of 160 mm.
23、Method D: Counting shall be carried out according to Method D of ASTM E45 standard over a surface of 160 mm (i.e. 320 fields). Other counting method shall be used prior agreement, in that case maximum series (thin and thick) allowed on 20 mm (40 fields). 7 Acceptance criteria 7.1 Steels Unless other
24、wise specified in the material standard or order the standard acceptance criteria according Table 3 and Annex A shall be used. prEN 2951:2017 (E) 5 The maximum number of fields allowed with fine or coarse series inclusions is specified for each inclusion class concerned in the applicable standard. T
25、able 3 Categories for inclusion content in steel Melting route Steel types Category Air melted Carbon and low alloy 1 Non corrosion resisting martensitic high alloy 1 Corrosion resisting martensitic 2 Corrosion resisting precipitation hardening 2 Single vacuum remelt All 3 Double vacuum remelt All 5
26、 Electroslag remelt Carbon and low alloy 3 Non corrosion resisting martensitic high alloy 4 Corrosion resisting martensitic 4 Corrosion resisting precipitation hardening 4 We authorize either the worst field and the average of all result par cast. 7.2 Other metallic materials The acceptance criteria
27、 shall be defined in the material standard or order. prEN 2951:2017 (E) 6 Annex A (normative) Acceptance criteria Categories A.1 Categories of acceptance Table A.1 Categories of acceptance Category 1 (worst field or average) ASTM E45: Method A Plate I-r A B C D Thin Heavy Thin Heavy Thin Heavy Thin
28、Heavy Worst field severity per specimen 2,5 2 3* 2,5 2,5 2 2 2 Average of all results per cast tested 2 1,5 2,5 2 2 1,5 1,5 1,5 Category 2 (worst field or average) ASTM E45: Method A Plate I-r A B C D Thin Heavy Thin Heavy Thin Heavy Thin Heavy Worst field severity per specimen 2,5 2 3,5 3 2,5 2 2,5
29、 2,5 Average of all results per cast tested 2 1,5 3 2,5 2 1,5 2 2 Category 3 (worst field or average) ASTM E45: Method A or D Plate I-r A B C D Thin Heavy Thin Heavy Thin Heavy Thin Heavy Worst field severity per specimen 1,5 1,5 1,5 1,5 1,5 1,5 1,5 1,5 Average of all results per cast tested 1,5 1 1
30、,5 1 1,5 1 1,5 1 Category 4 (worst field or average) ASTM E45: Method A or D Plate I-r A B C D Thin Heavy Thin Heavy Thin Heavy Thin Heavy Worst field severity per specimen 1,5 1,5 1,5 1,5 1,5 1,5 1,5 1,5 Average of all results per cast tested 1,5 1 1,5 1 1,5 1 1,5 1 Total rateable field frequency (
31、maximum) 1) * 1 * 1 * 1 50 3 prEN 2951:2017 (E) 7 Category 5 (worst field or average) ASTM E45: Method D Plate I-r A B C D Thin Heavy Thin Heavy Thin Heavy Thin Heavy Worst field severity per specimen 1,5 1 1 1 1 1 1,5 1 Worst field frequency (maximum) * 1 * 1 * 1 3 1 Total rateable field frequency
32、(maximum) 1) * 1 * 1 * 1 5 1 NOTE 1 Category 3 and 4: The choice of method is the suppliers option unless if its required in the material data sheet. NOTE 2 Category 4: if method A is chosen the line 3 is not applicable. If method D is chosen the line 3 is applicable (total rateable field frequency)
33、. * One field of B 3,5 Thin permitted per sample examined. * Not more than three (3) fields with a maximum permitted severity any combination of A, B and C type thin inclusions. For example of use see Annex informative A.2. * Not more than eight (8) rateable fields with any combination of A, B and C
34、 type thin inclusions. For example of use see Annex informative A.2. 1) A rateable field is defined as one which has a type A, B, C or D thin or heavy inclusion rating of at least 1,0 in accordance with the dimensional limiltations specified in Method D of ASTM E45. A.2 Example of the use of combine
35、d field ratings The following examples are intended to clarify note * and * of Table A.1. Example 1 Assessing a sample in accordance with the acceptance criteria of category 5. If a sample contains thin inclusions with one (1) field with a worst severity level of 1,5 for type A, one field with worst
36、 severity level of 1 for type B and one field with worst severity level of 1 for type C, the result complies with note *; To also comply with note * only five (5) more fields containing rateable inclusions with combinations A, B and C type inclusions would be allowed. Example 2 Similary, assessing a
37、 further sample in accordance with the acceptance criteria of category 5. If a sample contains thin inclusions with two (2) fields with a worst severity level of 1,5 for type A, no fields with a worst severity level of 1 for type B and no fields with a worst severity level of 1 for type C, the resul
38、t complies with note * ; To also comply with note *, six (6) other fields containing rateable inclusions with combination of A, B and C type would be allowed. prEN 2951:2017 (E) 8 Annex B (informative) Standard evolution form The main changes with respect to the previous edition are listed in Table
39、B.1. Table B.1 Main changes to previous edition prEN/EN Number Edition Publication Date Modification Reason and validation prEN 2951 P1 11/1997 In all of the document: “ASTM E45-95a“ replaced by “ASTM E45“. Title of clause 6: “Classification of defects“ replaced by “Classification of inclusions“. In
40、 clause 6: Clarification of the counting method according to test method A and test method B. In clause 7.1 and Annex A: Clarification that we authorize either the worst field or the average of all result per cast. Table A.1, category 2: For inclusion type D: update of the values of the line “averag
41、e of all results per cast tested“. Table A.1, category 3: a/Deletion of the lines “worst field frequency (maximum)“ and “total rateable field frequency (maximum)“. b/Test method A is now also allowed. c/For all inclusion types: update of the values of the line “worst field severity per specimen“. d/
42、Add of the line “average of all results per cast tested“. Table A.1, category 4: a/Deletion of the line “worst field frequency (maximum)“. b/Test method A is now also allowed. c/For all inclusion type: update of the values of the line “worst field severity per specimen“. d/Add of the line “average of all results per cast tested“. Clause A.2: Examples are now according to category 5 (and not category 4).
