1、BS EN 2950:2008ICS 49.025.01NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDAerospace series Test method Wrought heatresisting alloys Semi-finished products andparts Conditionsfor macrographicand micrographicexamination Atlas ofstructures and defectsThis British
2、 Standardwas published under theauthority of the StandardsPolicy and StrategyCommittee on 31 July 2009 BSI 2009ISBN 978 0 580 67793 9Amendments/corrigenda issued since publicationDate CommentsBS EN 2950:2008National forewordThis British Standard is the UK implementation of EN 2950:2008.The UK partic
3、ipation in its preparation was entrusted to TechnicalCommittee ACE/61/-/48, Heat resisting alloys.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are respons
4、ible for its correct application.Compliance with a British Standard cannot confer immunityfrom legal obligations.BS EN 2950:2008EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 2950August 2008ICS 49.025.01English VersionAerospace series - Test method - Wrought heat resisting alloysSemi-finished pro
5、ducts and parts - Conditions for macrographicand micrographic examination - Atlas of structures and defectsSrie arospatiale - Mthode dessais - Demi-produits etpices corroys en alliage rsistant chaud - Conditionsdexamens macrographique et micrographique - Atlas destructures et de dfautsLuft- und Raum
6、fahrt - Prfverfahren - UmgeformteErzeugnisse aus hochwarmfesten Legierungen -Prfbedingungen fr makrographische undmikrographische Untersuchung - Gefge- und FehleratlasThis European Standard was approved by CEN on 7 March 2008.CEN members are bound to comply with the CEN/CENELEC Internal Regulations
7、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 CEN Management Centre or to any CEN member.This European S
8、tandard 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 CEN Management Centre has the same status as theofficial versions.CEN members are the national st
9、andards bodies of Austria, Belgium, Bulgaria, 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 Ki
10、ngdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2008 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 2950:2008: EBS EN 295
11、0:2008EN 2950:2008 (E) 2 Contents Page Foreword3 1 Scope 4 2 Normative references 4 3 Terms and definitions .4 4 Macrographic examination .5 5 Micrographic examination 7 6 Reporting of results.8 Annex A (normative) Atlas of macrographic references.9 Annex B (normative) Atlas of micrographic referenc
12、es32 BS EN 2950:2008EN 2950:2008 (E) 3 Foreword This document (EN 2950:2008) has been prepared by the Aerospace and Defence Industries Association of Europe - Standardization (ASD-STAN). After enquiries and votes carried out in accordance with the rules of this Association, this Standard has receive
13、d the approval of the National Associations and the Official Services of the member countries of ASD, prior to its presentation to CEN. 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 200
14、9, and conflicting national standards shall be withdrawn at the latest by February 2009. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent right
15、s. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Ital
16、y, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 2950:2008EN 2950:2008 (E) 4 1 Scope The present document defines the conditions for the macrographic and micrographic examination of h
17、eat resisting alloy semi-finished and parts. It includes an atlas of commonly encountered and structural defects. The present document shall be applied in conjunction with the material standards specifying the criteria of acceptance. The present document is not intended to apply to cast or powder me
18、tallurgy products. 2 Normative references The 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 2078
19、, Aerospace series Metallic materials Manufacturing schedule, inspection schedule, inspection and test report Definition, general principles, preparation and approval 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 tree rings one or more conc
20、entric or non-concentric rings evidenced by a difference in texture associated with minor composition gradients due to ingot solidification 3.2 dendritic aspect coarse structure having a fir-tree like appearance initiated during the solidification of the ingot 3.3 grain flow fibre like lines which a
21、re caused by orientation of the constituents of the metal during deformation 3.4 recrystallisation formation of a new grain structure from that existing previously 3.5 freckles a type of segregation consisting of circular or near-circular dark etching areas, generally enriched with carbides and hard
22、ening elements 3.6 white spots a type of segregation consisting of bright white areas having bulk or fibrous configuration, generally depleted in carbides and hardening elements 3.7 stringer predominantly straight linear formation which is 2 particles in width BS EN 2950:2008EN 2950:2008 (E) 5 3.8 c
23、luster predominantly straight elongated formation which is mainly 2 particles in width 3.9 chain linear formation whose particle distribution does not lie predominantly in a straight line 3.10 random distribution of particles with no particular orientation 4 Macrographic examination 4.1 General Macr
24、ographic examination shall be carried out in accordance with this standard and by reference to Annex A (normative) to verify that the requirements of the relevant material standard, technical specification or order have been met. 4.2 Product surface examination 4.2.1 General Examination shall be per
25、formed on the entire surface of the product in the delivery heat treatment condition unless otherwise agreed between the manufacturer and the purchaser. Handling zones which may cause imperfect etching shall be defined and agreed between the manufacturer and the purchaser, and shall not be taken int
26、o account in the evaluation. 4.2.2 Surface preparation Preparation shall not alter, contaminate or cold work the surface structure. The product shall be cleaned and degreased to ensure uniform etching. 4.2.3 Macroetching The etching method to be used shall be agreed between the manufacturer and purc
27、haser. A list of typical etching reagents and conditions are given in Table 1. All structural characteristics, particularly the segregation resulting from solidification of the ingot shall be revealed. After etching, the surfaces shall be cleaned in a way which does not affect the quality of the con
28、trast and shall be protected from deterioration and contamination until inspection is carried out. 4.2.4 Examination Examination shall be carried out under a minimum light intensity of 250 Lux. Examination shall normally be performed without magnification but when necessary may be supplemented by th
29、e use of a magnification up to a maximum of 12. In case of doubt or when the structural features are unusual, a micrographic examination of the affected area shall be made in accordance with Clause 5. BS EN 2950:2008EN 2950:2008 (E) 6 4.3 Cut-up examination 4.3.1 General Unless otherwise agreed betw
30、een the manufacturer and the purchaser, examination shall be performed on a plane section of the product in the delivery heat treatment condition. The location and orientation of the plane section shall be as required by the relevant technical specification or order. The cutting method shall not cau
31、se damage to the structure. Slices shall be of sufficient thickness to allow further examination perpendicular to this plane section if required. 4.3.2 Surface preparation The surface to be examined shall be prepared in such a way that any contamination and mechanical alteration of the surface are a
32、voided or eliminated. The resulting surface shall be cleaned and degreased to ensure uniform etching. 4.3.3 Macroetching Wherever possible, electro-chemical techniques shall be used. The etching method to be used, shall be carried out by a technical agreed between manufacturer and purchaser. A list
33、of typical etching reagents and conditions is given in Table 1. Etching shall reveal all structure characteristics, particularly segregation resulting from the ingot solidification. After etching, the surface shall be cleaned in a way which does not affect the quality of the contrast and shall be pr
34、otected from deterioration and contamination until inspection is carried out. Table 1 Etchant Alloy type Name Composition vol. % Conditions Fe, Ni base Hydrochloric etch HCl . 50 H2O 50 Electrolytic (40 A/dm2 l 100 A/dm2) Ambient temperature Fe, Ni base with Nb Ferric chloride FeCl3 .49 HCl . 4 H2O
35、47 Chemical 40 C 120 C Fe, Ni, Co base Sulphuric etch H2SO4 95 H2O 5 Electrolytic 25 A/dm2Ambient temperature 4.3.4 Examination Macrographic examination shall be carried out in accordance with 4.2.4. BS EN 2950:2008EN 2950:2008 (E) 7 5 Micrographic examination 5.1 General Micrographic examination sh
36、all be carried out in accordance with this standard and by reference to Annex B (normative) and to verify the requirements of the relevant material standard and/or order have been met. 5.2 Product surface examination 5.2.1 General Examination shall be carried out to investigate anomalies observed du
37、ring macrographic examination (see 4.2.4) or when required by the material standard. 5.2.2 Surface preparation Material shall be removed from the surface to be examined until it is polished to a mirror finish and is free from cold working, contamination and the effects of prior surface preparation.
38、5.2.3 Microetching Micro examination may be required in either or both polished and etched conditions. When etching is required, the method to be used shall be agreed between manufacturer and purchaser. A list of typical etching reagents and conditions is given in Table 2. After etching, the surface
39、s shall be cleaned in a way which does not affect the quality of the contrast, and shall be protected from deterioration and contamination until examination is carried out. Table 2 Etchant Alloy type Name Composition Conditions Co base Nital 2 % HNO3 10 % ethyl alcohol Electrolytic Ambient temperatu
40、re Fe, Ni base low Al, Ti content Frys reagent CuCl220 gHCl . 200 ml H2O 100 ml Chemical Ambient temperature Fe, Ni, Co base Murakamis reagent KOH 10 g K3Fe(CN)4. 8 g H2O 100 ml Chemical 60 C 90 C Ni base high Al, Ti content Glyceregia HCl . 20 ml HNO310 ml Glycerol . 35 ml Electrolytic Ambient temp
41、erature Ni base High Cr, Al, Ti content HF/Glycerol HF . 5 ml Glycerol . 10 ml H2O 85 ml Electrolytic Ambient temperature 5.2.4 Examination Examination shall be carried out directly on the prepared surface or by using a replica, under an optical microscope with a minimum magnification of 50. BS EN 2
42、950:2008EN 2950:2008 (E) 8 Wherever possible, examination shall be made at the same magnification as the reference photomicrograph. In all cases, the magnification used shall permit resolution of the structural characteristics sought. 5.3 Cut-up examination 5.3.1 General Examination shall be carried
43、 out on a plane section of the product in order to investigate anomalies observed during macrographic examination (see 4.3.4) or when required by the material standard, technical specification or order. In case of such a requirement, this examination shall be carried out in the heat treatment condit
44、ion required by the relevant material standard. 5.3.2 Sampling The location and orientation of samples shall be as required by the relevant material standard or order or as determined by the presence of macro anomalies. The sampling method shall not cause damage to the structure. 5.3.3 Surface prepa
45、ration The surface preparation shall be carried out in accordance with 5.2.2. 5.3.4 Microetching Microetching shall be carried out in accordance with 5.2.3. 5.3.5 Examination Examination shall be carried out in accordance with 5.2.4. 6 Reporting of results The results of macro or micro examination s
46、hall be recorded in the inspection and test report in accordance with EN 2078. Each photograph of the structure shall be identified with the location, orientation, etch method and magnification. BS EN 2950:2008EN 2950:2008 (E) 9 Annex A (normative) Atlas of macrographic references A.1 Tree rings A.1
47、.1 Concentric tree rings See Figure A.1 (A to E). A B BS EN 2950:2008EN 2950:2008 (E) 10 C D BS EN 2950:2008EN 2950:2008 (E) 11 E Figure A.1 BS EN 2950:2008EN 2950:2008 (E) 12 A.1.2 Non-concentric tree ring See Figure A.2 (A to F). A B BS EN 2950:2008EN 2950:2008 (E) 13 C D BS EN 2950:2008EN 2950:20
48、08 (E) 14 E F Figure A.2 BS EN 2950:2008EN 2950:2008 (E) 15 A.2 Dendritic aspect See Figure A.3 (A to E). A B BS EN 2950:2008EN 2950:2008 (E) 16 C D BS EN 2950:2008EN 2950:2008 (E) 17 E Figure A.3 BS EN 2950:2008EN 2950:2008 (E) 18 A.3 Grain flow A.3.1 Regular See Figure A.4. Figure A.4 A.3.2 Irregu
49、lar See Figure A.5. Figure A.5 BS EN 2950:2008EN 2950:2008 (E) 19 A.4 Macro-recrystalisation A.4.1 Central coarsening See Figure A.6. Figure A.6 A.4.2 Central and outer See Figure A.7. Figure A.7 BS EN 2950:2008EN 2950:2008 (E) 20 A.4.3 Central and ring See Figure A.8. Figure A.8 A.4.4 Random See Figure A.9. Figure A.9 BS EN 2950:2008EN 2950:2008 (E) 21 A.4.5 Square shape recrystalisation See Figure A.10 (A to H). Figure A.10 BS EN 2950:2008EN 2950:2008 (E) 22 A.4.6 Outer critical grain growth See Figure A.11. Figure A.11 A.5 Freckles Se
