1、I-. CEN EN*ISO*2624 75 M 3484589 0105116 822 M BRITISH STANDARD Copper and copper alloys - Estimation of average grain size The European Standard EN IS0 2624 : 1995 has the status of a British Standard BS EN IS0 2624 : 1995 BS EN IS0 2624 : 1995 under the authority of the Standards Board and comes i
2、nto Amd. No. Date effect on 15 September 1995 O BSI 1995 The following BSI references relate to the work on this standard: Committee reference NFE/34 Draft for comment 90137770 DC ISBN O 580 24476 8 Committees responsible for this British Standard Text affected The preparation of this British Standa
3、rd was entrusted to Technical Committee NFE/34, Copper and copper alloys, upon which the following bodies were represented: British Bathroom Council British Cable Makers Confederation British Non-ferrous Metals Federation British Refrigeration Association British Valve and Actuator Manufacturers Ass
4、ociation Copper Development Association London Metal Exchange Non-ferrous Metal Stockists Transmission and Distribution Association (BEAMA Limited) Coopted members The following bodies were also represented in the drafting of the standard, through subcommittees and panels: British Plumbing Fittings
5、Manufacturers Association British Railways Board British Turned-parts Manufacturers Association Institution of Incorporated Executive Engineers London Regional Transport National Association of Plumbing, Heating and Mechanical Services Power Generation Contractors Association (PGCA) (BEAMA Ltd.) Spr
6、ing Research and Manufacturers Association Contractors CEN EN*IS0*2624 95 = 3404589 OLOSLLB bT5 W BS EN IS0 2624 : 1995 Contents Committees responsible National foreword Page Inside front cover 11 Foreword 2 Introduction 2 Specification 1 Scope 3 2 Symbols and designations 3 3 Test samples 3 4 Proce
7、dures 3 5 Rst report 4 A Standard grain size charts (x 75) 5 1 Jeffries multipliers for area of 5000 mm2 4 Annex ables 2 Relationships between the actual grain size of specimens viewed at various magnifications and the standard series of photomicrographs 4 . i CEN EN*IS0*2624 95 m 3404589 0105119 53
8、1 m BS EN IS0 2624 : 1995 National foreword This British Standard has been prepared by %chnical Committee NFE/34 and is the English language version of EN IS0 2624 : 1995 Copper and copper alloys - Estimation of average pain size, published by the European Committee for Standardization (CEN). It sup
9、ersedes BS 7428 : 1991 which is withdrawn. EN IS0 2624 : 1995 is identical with IS0 2624 : 1990, published by the International Organization for Standardization (BO). It was produced as a result of international discussions in which the United Kingdom took an active part. The standard grain size cha
10、rts in normative annex A are reproduced with permission from the annual book of ASTM Standards (Copyright ASTM). Compliance with a British Standard does not of itself confer immunity from legai obligations. ii CEN EN*IS0*2624 35 m 3404589 0105120 253 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM
11、 EN IS0 2624 May 1995 ICs 77.040.30 Descriptors: copper, copper alloys, grain size analysis, microstructure, grain structure, microscopy, microphotography English version Copper and copper alloys - Estimation of average grain size (IS0 2624 : 1990) Cuivre et alliages de cuivre - Evaluation de la dim
12、ension moyenne du grain (IS0 2624 : 1990) Kupfer- und Kupferlegierungen - Bestimmen der mittleren Korngrge (IS0 2624 : 1990) This European Standard was approved by CEN on 1995-02-26. CEN members are bound to comply with the CENICENELEC Internal Regulations which stipulate the conditions for giving t
13、his 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
14、(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, Denma
15、rk, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B
16、-1050 Brussels O 1995 All rights of reproduction and communication in any form and by any means reserved in all countries to CEN and its members Ref. No. EN IS0 2624 : 1095 E CEN EN*ISO*2624 95 3404589 0105121 L9T Page 2 EN IS0 2624 : 1995 Foreword The text of the International Standard from ISO/TC
17、26, Copper and copper alloys, of the International Organization for Standardization (ISO) has been taken over as a European Standard by CEN/TC 133, Copper and copper alloys. The European Standard shall be given the status of a national standard, either by publication of an identical text or by endor
18、sement, at the latest by November 1995, and conflicting national standards shall be withdrawn at the latest by November 1995. According to the CENKENELEC Internal Regulations, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany,
19、Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, United Kingdom. Introduction On a section of metal, a grain is that area within the boundary of a crystal. For the purpose of applying the methods described in this International Standard, a cryst
20、al and its twin bands are considered as one grain. Sub-grains, minor constituent phases, inclusions and additives are not considered in the estimation of the grain size. It is important, in using these methods, to recognize that the estimation of grain size is not a precise measurement, A metal stru
21、cture is an aggregate of three-dimensional crystals of varying sizes and shapes. Even if all these crystals were identical in size and shape, the grain cross-sections produced by a random plane (surface of observation) through such a structure would have a distribution of areas varying from a maximu
22、m value to zero, depending upon where the plane cuts each individual crystal. Clearly, no two fields of observation can be exactly the same. Practical reasons limit the number of grains that can reasonably be counted to less than the number statistically desirable. CEN EN*ISO*2624 95 3404589 0305322
23、 O26 Page 3 EN IS0 2624 : 1995 Copper and copper alloys - Estimation of average grain size 1 Scope This International Standard specifies three procedures for estimating, and rules for expressing, the average grain size of copper and copper alloys consisting principally of a single phase. The respect
24、ive procedures are termed the comparison procedure, the intercept procedure and the planimetric pro- cedure. The comparison procedure (comparing the specimen with a standard chart) is most convenient and is sufficiently accurate for most commercial purposes. Higher degreees of accuracy in estimating
25、 grain size are ob- tainable by using the intercept (Heyn) or planimetric (Jeffries) procedures. In cases of dispute, it is recommended that the use of one of these procedures be agreed between the parties. For material with non-equiaxial structures it is recommended that the intercept procedure be
26、used. 2 Symbols and designations Symbol f m d I Y Designation Jeffries multiplier used to obtain number of grains per square millimetre by planimetric method Number of grains per square millimetre Average grain “diameter” in millimetres; an arbitrary measure defined as 1 /fi Average intercept length
27、 Magnification 3 Test samples 3.1 Grain size estimations shall be made on three or more representative fields of each sample section. In known equiaxial structures only a representative section need be taken on the sample. For non-equiaxial or unknown structures three sec- tions must be prepared, ea
28、ch at right angles to the other. 3.2 The specimen shall be carefully prepared to reveal the grain boundaries using a contrast etch to match the standard charts. 4 Procedures 4.1 Comparison procedure The estimation of grain size is made by direct comparison of a projected image of a photomicrograph o
29、f a representative field of the test specimen, either with the photomicrographs of the standard grain size series or with suitable reproductions of them (for standard grain size charts, see annex A); when a pro- jection microscope is not available a bench microscope may be used. It is recommended th
30、at, to facilitate comparison, mechanical arrangements be made to permit bringing the stan- dard photomicrographs successively into juxtaposition with the projected image. 4.2 Intercept procedure 4.2.1 The grain size is estimated by counting, on the ground glass screen of a projection microscope, on
31、the image in a bench microscope fitted with a graticule, on a photo- micrograph of a representative field of the specimen, or on the specimen itself, the number of grains intercepted by one or more straight lines sufficiently long to yield at least 10 inter- cepts per line and at least 50 intercepts
32、 for all lines for normal purposes and at least 200 intercepts for referee purposes. Grains touched by the end of the line count only as half grains. The length of the line or lines in millimetres at the surface of the section, divided by the number of grains intersected by it, gives the average int
33、ercept length I. For practical purposes, the ave- rage intercept length, I, may be regarded as equal to the ave- rage grain diameter d”. 4.2.2 For non-equiaxial structures, measurements should be made on longitudinal and transverse sections along lines that lie in all three principal directions of t
34、he specimen. For each direc- tion, the average grain “diameters” should be calculated as in 4.2.1. 1) multiplied by the factor 1,13. To achieve compatibility with estimations of grain “diameter” made by the planimetric or comparison procedure, the intercept length, /, should be CEN EN*IS0*2624 75 34
35、04589 0105123 Tb2 Page 4 EN IS0 2624 : 1995 c x 75 (standard) x 25 x50 x 100 x 200 x500 4.3 Planimetric procedure 0,010 0,015 0,020 0,025 0,035 0,045 0,050 0.060 0,070 0,030 0,045 0,060 0.080 0,110 0.140 0.150 0,180 0,210 0,015 0,020 0,030 0,040 0,050 0,070 0.080 0.090 0.100 0,008 0,010 0,015 0,020
36、0,025 0,035 0.040 0,045 0,050 - 0,005 0,007 0,010 0,012 0,017 0,020 0,022 0,025 - - - - 0,005 0,007 0,008 0,009 0,010 4.3.1 In the planimetric procedure, a circle or rectangle of known area (usually 5 O00 mm2 to simplify the calculation) is inscribed on a photomicrograph or on the ground glass scree
37、n of the projection microscope. A magnification should be selected which will give at least 50 grains for normal purposes and 200 grains for referee purposes in the field to be counted. When the image is focused properly, the number of grains within this area should be counted. The sum of all the gr
38、ains included completely within the known area plus one half the number of grains intersected by the circumference of the area should be taken as giving the number of equivalent whole grains, measured at the magnifi- cation used, within the area. If this number is multiplied by Jeffries multiplier,
39、.f, in the second column of table 1 opposite the appropriate magnification, the product will be the number of grains per square millirnetre, m. 4.3.2 The average grain “diameter“ in millimetres, d, for each field may then be calculated from the formula d = 1/ for example, at x 250 divide by 10 the g
40、rain size indicated at x 25, or at x 400 divide by 2 the grain size indicated at x 200. Thus at x 250. a grain size which will match the same standard photograph of 0,050 mm at x 75 will be a 0,015 mm grain size (0.150 at x 25 divided by 10). It should be appreciated that it is not uncommon for oper
41、ators to differ by one step in the charts when estimating the grain size of a given field. 5.2 Intercept or planimetric procedures In equiaxial material, the results for each of the three or more representative fields on which estimations have been made shall be reported. Alternatively, where a sing
42、le figure isrequired the median of these results shall be reported. In non-equiaxial material, when the intercept proceduFe should be used, the results for each of the three directions shall be reported either for individual fields or as the corresponding me- dian for each direction. 5.3 Mixed grain
43、 sizes These are sometimes encountered, for example in hotworked metal. These shall be expressed by giving the estimated area percentages occupied by the two sizes or the two ranges of sizes, by using the comparison method. Table 2 - Relationships between the actual:grain size of specimens viewed at
44、 various magnifications and the standard series of photomicrographs I Image I Grain size when image matches standard chart 1 I magnification I mm CEN EN*ISO*2624 95 3404589 0305324 9T9 Page 5 EN IS0 2624 : 1995 Annex A (normative) Standard grain size charts (x 75) NOTE - The reference photomicrograp
45、h plates given in this annex are taken from the ASTM standard E112-85, Standardmethods for determining the average grain size, Plate I I I. CEN EN*ISO*2624 95 3404587 0105125 835 Page 6 EN IS0 2624 : 1995 - CEN EN*IS0*2624 95 H 3404589 0105126 771 Page 7 EN IS0 2624 : 1995 * 0,120 mm average grain d
46、iameter grain diameter grain diameter grain diameter CEN EN*ISO*2b24 95 W 3404589 OL05L27 bo8 W Page 8 EN IS0 2624 : 1995 grain diameter grain diameter grain diameter grain diameter CEN EN*IS0*2624 95 3404589 ClL5128 544 Page 9 EN IS0 2624 : 1995 . -. . . - .- . . . grain diameter grain diameter gra
47、in diameter CEN EN*ISO*2624 75 m 3404589 OLO5L27 480 m BS EN IS0 2624 : 1995 CEN EN*IS0*2624 75 3404587 0105130 IT2 BS EN IS0 2624 : 1995 BSI 389 Chiswick High Road London W4 4AL 9509- 6- 0.35k- RTL BSI - British Standards Institution BSI is the independent national body responsible for preparing Br
48、itish Standards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter. Contract requirements A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their c
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