BS EN 12402-1999 Lead and lead alloys - Methods of sampling for analysis《铅和铅合金 分析用取样方法》.pdf

1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN 12402:1999 The Euro

2、pean Standard EN 12402:1999 has the status of a British Standard ICS 77.120.60 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Lead and lead alloys Methods of sampling for analysisThis British Standard, having been prepared under the direction of the Engineering Sector Committ

3、ee, was published under the authority of the Standards Committee and comes into effect on 15 December 1999 BSI 12-1999 ISBN 0 580 32842 2 BS EN 12402:1999 Amendments issued since publication Amd. No. Date Comments National foreword This British Standard is the English language version of EN 12402:19

4、99. It supersedes BS 3908-1:1965 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee NFE/22, Lead and lead alloys, which has the responsibility to: aid enquirers to understand the text; present to the responsible European committee any enquiries on the in

5、terpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards

6、which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard doe

7、s not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an insi

8、de front cover, the EN title page, pages 2 to 8, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued.CEN European Committee for Standardization Comite Europe en de Normalisation Europa isches Komitee fu r Normung Cent

9、ral Secretariat: rue de Stassart 36, B-1050 Brussels 1999 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 12402:1999 E EUROPEAN STANDARD EN 12402 NORME EUROPE ENNE EUROPA ISCHE NORM August 1999 ICS 71.040.40; 77.120.60 English vers

10、ion Lead and lead alloys Methods of sampling for analysis Plomb et alliages de plomb Me thodes de chantillonnage pour analyse Blei und Bleilegierungen Probenahme fu r die Analyse This European Standard was approved by CEN on 2 July 1999. CEN members are bound to comply with the CEN/CENELEC Internal

11、Regulations which stipulate the conditions for giving this 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. Th

12、is European Standard exists in three official versions (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 t

13、he national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.Page 2 EN 12402:1999 BSI 12-1999 Foreword This European Standard has been pre

14、pared by Technical Committee CEN/TC 306, Lead and lead alloys, the Secretariat of which is held by AFNOR. 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 2000, and conflicting national st

15、andards shall be withdrawn at the latest by February 2000. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Ic

16、eland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Contents Page Foreword 2 1 Scope 3 2 Normative references 3 3 Definitions 3 4 Principle 3 5 Sampling of molten lead and lead alloys 3 5.1 Conditions for sampling 3 5.2 Apparatus 3 5.3

17、 Procedure 3 6 Sampling of lead and lead alloy ingot consignment for chemical analysis 4 6.1 Selection of ingots 4 6.2 Sample preparation 4 6.3 Laboratory samples 5 7 Sampling of a single ingot of lead or lead alloy 5 7.1 Sample preparation 5 7.2 Laboratory samples 5 8 Safety 6 Annex A (informative)

18、 Example of mould to obtain mushroom-shaped disc of metal (cross-section) 8Page 3 EN 12402:1999 BSI 12-1999 1 Scope This European Standard specifies the methods of sampling of lead and lead alloys for the purpose of chemical analysis or for the purpose of spectrometric analysis by optical emission s

19、pectrometry (OES), with spark excitation. 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited, at the appropriate places in the text and the publications are listed hereafter. For dated ref

20、erences, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. ENV 12908:1997, Lead and lead alloys Analysis by optica

21、l emission spectrometry (OES), with spark excitation. 3 Definitions For the purposes of this European Standard, the following definitions apply. 3.1 cast product of one furnace or crucible melt NOTE All the ingots from a single cast have the same identifying mark. 3.2 ingot cast product intended for

22、 remelting and/or processing 3.3 jumbo or block very large ingot with a mass generally much more than 50 kg 3.4 bundle collection of ingots taken from a single cast and secured if necessary, for the purposes of handling, shipment and storage 3.5 sample portion of lead or lead alloy representative of

23、 the chemical composition 3.6 laboratory sample final form of the sample submitted for analysis 4 Principle Since lead and lead alloys can have different shapes and masses (ingots, jumbos) which are not easily handled, sampling from the molten metal during the casting process is recommended. Neverth

24、eless, sampling from a consignment shall be feasible, if required, in any case of dispute. 5 Sampling of molten lead and lead alloys 5.1 Conditions for sampling All samples representing a cast shall be taken from the molten metal under the appropriate conditions of temperature, mixing and cleanlines

25、s to ensure that the molten metal is homogeneous. These conditions will depend on the characteristics of the metal to be sampled, but are particularly important for lead alloys, many of which are subject to segregation if conditions are incorrect. 5.2 Apparatus All apparatus used shall be clean and

26、be inert to the molten metal. 5.2.1 Ladle The ladle shall be large enough to allow the sample mould to be filled in one operation. 5.2.2 Sample mould The sample mould shall be designed to cool the molten metal as rapidly as possible to avoid segregation. An example is proposed in annex A (informativ

27、e). Samples shall be of suitable dimensions to be analysed on any usual spectrometer (OES). The minimum thickness of the disc shall be 5 mm. The maximum thickness and the diameter depend on the dimensions of the sample platform of the spectrometer, but shall not be so large that segregation can occu

28、r within the sample due to an extended cooling time. 5.3 Procedure 5.3.1 Collection of samples Preheat the ladle by holding it in the molten metal of an ingot mould during filling. When heated, fill the ladle from the molten metal and, without delay, fill the sample mould in one pouring operation. W

29、hen the metal has completely solidified, remove the sample from the mould, cool, and mark with its sample identity. If it is necessary to pour samples in quick succession, several sample moulds shall be used to avoid the possibility of a slower rate of cooling allowing segregation to occur. WARNING.

30、 Due to the inherent risks associated with high temperatures, molten metal and moving machinery, only properly trained personnel wearing appropriate personal protective equipment may carry out the sampling. NOTE For process control, the following method should be used for sampling of metal in the ke

31、ttle: preheat the ladle by holding it in the molten metal; thoroughly mix the lead bath using an appropriate mixer; fill the preheated ladle while the lead remains well stirred, and without delay; fill the sample mould in one processing operation. Continue the operations as described above.Page 4 EN

32、 12402:1999 BSI 12-1999 5.3.2 Frequency of sampling 5.3.2.1 Lead Samples shall be taken at the beginning and end of a cast as a minimum. NOTE Additional samples can be agreed between the supplier and the purchaser. 5.3.2.2 Lead alloys Samples shall be taken at the beginning, middle and end of a cast

33、 as a minimum. NOTE Additional samples can be agreed between the supplier and the purchaser. 5.3.3 Identification Each sample shall be permanently identified with a unique identity and, preferably, the cast identity. 5.3.4 Sample preparation 5.3.4.1 Samples for spectrometric analysis The final surfa

34、ce of the sample disc shall be prepared immediately prior to the analysis. Surface preparation is detailed in ENV 12908:1997. 5.3.4.2 Samples for chemical analysis Half of each sample shall be prepared by milling or filing through its depth. All the millings or filings from each separate sample shal

35、l be collected. Any iron particles introduced during the milling or filing operations shall be removed using a strong magnet. Thoroughly mix the sample to homogenize it. All the apparatus used shall be thoroughly cleaned prior to use. The speed of milling or filing shall be chosen in order to avoid

36、heating and oxidizing, without the use of a lubricant. For those lead alloy samples which are subject to segregation according to particle size, the millings or filings shall be screened through a sieve with an aperture size of 0,16 mm to provide two fractions, ensuring that all the sample is retain

37、ed. Each fraction shall be weighed to determine the proportion in percent. If any doubt exists concerning segregation of a lead alloy sample, the millings or filings shall be sieved. NOTE 1 Millings or filings should be not greater than 0,5 mm for their largest dimension. NOTE 2 The sample discs use

38、d for optical emission spectrometdc analysis (OES) can be used as samples if a subsequent chemical analysis is required. In this case, turnings obtained from a newly prepared surface (without any traces of sparks) can be used instead of millings or filings. 5.3.5 Laboratory sample For an unsieved sa

39、mple, place the millings or filings into a suitable container, close, and label; it constitutes the laboratory sample. For a sieved sample, place each of the two fractions into a suitable container, close and label the container specifying the size fraction and its percentage. Place the two containe

40、rs into a bag, seal if required and label the bag specifying the contents. The contents of the bag constitute the laboratory sample. 6 Sampling of lead and lead alloy ingot consignment for chemical analysis This procedure shall compulsorily be used in any case of dispute, and due to the nature of th

41、e sample produced, the analysis shall be carried out by chemical methods. NOTE Because of difficulties of sampling large ingots jumbos), the sampling procedure should be agreed between the supplier and the purchaser. 6.1 Selection of ingots 6.1.1 If the consignment consists of bundles from more than

42、 one cast, each cast shall be sampled separately. 6.1.2 From each cast delivered that is to be sampled, take at random from different bundles, a number of ingots, as given in Table 1. Table 1 Number of ingots for sampling Number of ingots Cast delivered Lead Lead alloys 10 up to l00 t up to 50 t 20

43、over 100 t over 50 t NOTE When the consignment consists of less than 10 ingots, the sampling procedure should be agreed between the supplier and the purchaser. If sampling according to this standard is required, all the ingots should be individually sampled according to clause 7. 6.1.3 Carefully cle

44、an the surface of each ingot selected to remove dirt, oil, grease, and any other contaminants. 6.2 Sample preparation For lead, obtain the sample by drilling or by sawing, in accordance with the procedures given in 6.2.2 or 6.2.3. NOTE The use of sawing is recommended. For lead alloys, only sawing s

45、hall be used due to the possibility of segregation. WARNING. Observe the appropriate safety recommendations for the use of mechanical equipment. Only properly trained personnel wearing appropriate personal protective equipment may carry out these operations. 6.2.1 Arrangement of ingots Arrange the s

46、elected ingots flat, side by side, in groups of ten ingots; ensure that the manufacturers identifying marks (usually cast into the base of the ingots) are arranged in the same way for each one of the ingots: for drilling (6.2.2), turn alternate ingots upside down as indicated in Figure 1a); for sawi

47、ng (6.2.3), arrange the ingots as indicated in Figure 1b). In each group, draw a diagonal across the rectangle thus formed see Figure 1a) or 1b).Page 5 EN 12402:1999 BSI 12-1999 6.2.2 Drilling Using a clean drill of appropriate dimensions, drill each ingot to half of its depth at the points indicate

48、d in Figure 1a). NOTE The use of a high speed steel drill of about 15 mm diameter is recommended. Carry out the drilling without undue heating which may cause oxidation, at a suitable drilling rate to obtain drillings of a thickness between 0,2 mm and 0,5 mm, without the use of lubricant. Collect al

49、l the drillings and crush them without undue heating which may cause oxidation (liquid nitrogen can be used to aid this operation). Remove any iron particles introduced during the drilling and crushing operations by using a strong magnet. Thoroughly mix the sample to homogenize it. 6.2.3 Sawing Using a mechanical saw with clean, paint-free saw blade of appropriate dimensions, saw completely through each ingot where the marked diagonal crosses the median line of the ingot as indicated in Figure 1b). NOTE The use of a saw blade of 1 m