1、BRITISH STANDARD BS 6783-7: 1986 EN 27526:1991 ISO 7526:1985 Incorporating Amendment No. 1 Sampling and analysis of nickel, ferronickel and nickel alloys Part 7: Method for determination of sulphur in nickel, ferronickel and nickel alloys by infra-red absorption after induction furnace combustion IS
2、O title: Nickel, ferronickel and nickel alloys Determination of sulfur content Infra-red absorption method after induction furnace combustion This European Standard EN 27526:1991 has the status of a British Standard UDC 669.24:669.1524-198:620.1:543.422.4:543.845BS6783-7:1986 This British Standard,
3、having been prepared under the directionof the Non-ferrous Metals Standards Committee, waspublished under the authorityof the Board of BSI andcomes into effect on 31 December 1986 BSI 10-1999 The following BSI references relate to the work on this standard: Committee reference NFM/10 Draft for comme
4、nt 84/39889 DC ISBN 0 580 15526 9 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Non-ferrous Metals Standards Committee (NFM/-) to Technical Committee NFM/10, upon which the following bodies were represented: British Non-ferrous Metals
5、Federation British Steel Industry Engineering Equipment and Materials Users Association Ministry of Defence Process Plant Association Stainless Steel Fabricators Association of Great Britain Coopted members Amendments issued since publication Amd. No. Date of issue Comments 6993 April 1992 Indicated
6、 by a sideline in the marginBS6783-7:1986 BSI 10-1999 i Contents Page Committees responsible Inside front cover National foreword ii 1 Scope and field of application 3 2 References 3 3 Principle 3 4 Reagents and materials 3 5 Apparatus 3 6 Sampling and samples 3 7 Procedure 3 8 Expression of results
7、 4 9 Notes on procedure and equipment 5 10 Test report 6 Annex A Examples of compositions of nickel, ferronickel and nickel alloys 7 Annex B Features of commercial high frequency induction furnaces and infra-red sulfur analysers 7 Table 1 Calibration example 4 Table 2 Results of statistical analysis
8、 5 Table 3 Examples of composition of nickel (%) 7 Table 4 Examples of composition of ferronickel (%) 7 Table 5 Examples of composition of nickel alloys (%) 8 Publications referred to Inside back coverBS6783-7:1986 ii BSI 10-1999 National foreword This Part of BS 6783 has been prepared under the dir
9、ection of the Non-ferrous Metals Standards Committee. It is identical with ISO7526:1985 “Nickel, ferronickel and nickel alloys Determination of sulfur content Infra-red absorption method after induction furnace combustion” published by the International Organization for Standardization (ISO). In 199
10、1 the European Committee for Standardization (CEN) accepted ISO7526:1985 as European Standard EN27526:1991 without any modifications. At present this British Standard consists of nine Parts all concerned with analysis of nickel, ferronickel and nickel alloys. Further International Standards are in p
11、reparation on sampling and analysis of nickel, ferronickel and nickel alloys and, when available, these will be published as further Parts of this British Standard. Terminology and conventions. The text of the International Standard has been approved as suitable for publication as a British Standard
12、 without deviation. Some terminology and certain conventions are not identical with those used in British Standards; attention is drawn especially to the following. The comma has been used as a decimal marker. In British Standards it is current practice to use a full point on the baseline as the dec
13、imal marker. Wherever the words “International Standard” appear, referring to this standard, they should be read as “Part of BS6783”. In British Standards it is current practice to use the symbol “L” for litre (and in its submultiples) rather than “l” and to use the spelling “sulphur”, etc., instead
14、 of sulfur, etc. A British Standard does 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. Cross-references Interna
15、tional Standards Corresponding British Standards ISO 5725:1981 BS 5497 Precision of test methods Part 1:1979 Guide for the determination of repeatability and reproducibility for a standard test method (Technically equivalent) ISO 7525:1985 BS 6783 Sampling and analysis of nickel, ferronickel and nic
16、kel alloys Part 6:1986 Method for determination of sulphur in nickel by methylene blue molecular absorption spectrometry after generation of hydrogen sulphide (Identical) Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theEN title page, pages 2 to 8, an
17、 inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 27526:1991 November 1991 UDC 669.24:669.1524
18、-198:620.1:543.422.4:543.845 Descriptors: Nickel, nickel alloys, ferronickel, chemical analysis, determination of content, sulphur, infrared spectroscopy, combustion analysis, induction furnaces English version Nickel, ferronickel and nickel alloys Determination of sulfur content Infra-red absorptio
19、n method after induction furnace combustion (ISO 7526:1985) Nickel, ferro-nickel et alliages de nickel Dosage du soufre Mthode par absorption dans linfrarouge aprs combustion dans un sour induction (ISO 7526:1985) Nickel, Ferronickel und Nickellegierungen Bestimmung des Schwefelgehaltes Verfahren de
20、r Infrarotabsorption nach Verbrennung im Induktionsofen (ISO 7526:1985) This European Standard was approved by CEN on 1991-11-06. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standa
21、rd 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 (English, French, German). A version in any other lan
22、guage 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, Denmark, Finland, France, Germany, Greece, Iceland, Irelan
23、d, 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-1050 Brussels CEN 1991 Copyright reserved to all CEN
24、 members Ref. No. EN 27526:1991 E2 blankEN 27526:1991 BSI 10-1999 3 1 Scope and field of application This International Standard specifies an infra-red absorption method after combustion for the determination of the sulfur content of nickel and ferronickel in the range0,001 to0,3%(m/m), and of nicke
25、l alloys in the range0,001 to0,1%(m/m). Examples of compositions are given in Annex A. NOTEIt may be possible to apply this method in the range0,000 2 to0,001% (m/m). However, there were insufficient laboratory test data to support the inclusion of this lower level in the scope. 2 References ISO 572
26、5, Precision of test methods Determination of repeatability and reproducibility by inter-laboratory tests. ISO 7525, Nickel Determination of sulfur content Methylene blue molecular absorption spectrometric method after generation of hydrogen sulfide. 3 Principle Combustion of a test portion in a flo
27、w of oxygen at a high temperature in a high frequency induction furnace in the presence of fluxes and accelerators. Measurement of the sulfur dioxide formed using an infra-red analyser and an integration procedure. 4 Reagents and materials 4.1 Oxygen (O 2 ), 99,5 % (m/m) minimum. 4.2 Ascarite or sod
28、a lime, 0,7 to 1,2 mm (14 to22mesh). 4.3 Magnesium perchlorate Mg(ClO 4 ) 2 , 0,7 to1,2mm (14 to 22 mesh). 4.4 Glass-wool 4.5 Crucibles and lids 4.5.1 Ceramic crucibles shall be of precise dimensions so that the sample is positioned correctly in the induction coil of the furnace (see9.1). 4.5.2 Pre-
29、ignite the crucibles in air or oxygen in a furnace for not less than1h at1100 C and store in a desiccator or closed container. A resistance furnace with a combustion tube through which a flow of oxygen passes may be used. Crucible lids, used to help retain the solid oxidation products in the hot zon
30、e, are pre-ignited in a similar manner. 4.6 Fluxes: Low sulfur tin, copper plus tin, copper or vanadium pentoxide (see 9.2). 4.7 Accelerators: Low sulfur copper, iron, tungsten or nickel (see 9.2). 4.8 Nickel, low sulfur of known value 0,001% (m/m). 4.9 Standard reference steels, containing 0,1 to0,
31、2% (m/m) sulfur. 5 Apparatus The apparatus required for combustion in a high frequency induction furnace and the subsequent infra-red absorption measurement of the evolved sulfur dioxide may be obtained commercially from a number of manufacturers. Follow the manufacturers instructions for the operat
32、ion of the equipment. A pressure regulator is required to control the oxygen pressure to the furnace according to the manufacturers specification (usually28kN/m 2 ). Features of commercial equipment are given in Annex B. 6 Sampling and samples 6.1 Sampling and preparation of the laboratory sample sh
33、all be carried out by normal agreed procedures or, in case of dispute, by the relevant International Standard. 6.2 The laboratory sample normally is in the form of a powder, granules, millings or drillings and no further preparation of the sample is necessary. 6.3 If it is suspected that the laborat
34、ory sample is contaminated with oil or grease from the milling or drilling process, it shall be cleaned by washing with high purity acetone and drying in air. 6.4 If the laboratory sample contains particles or pieces of widely varying sizes, the test portion should be obtained by riffling. 7 Procedu
35、re WARNING The risks related to combustion analysis are mainly burns in pre-igniting the ceramic crucibles and in the fusions. Use crucible tongs at all times and suitable containers for the used crucibles. Normal precautions for handling oxygen cylinders shall be taken. Oxygen from the combustion p
36、rocess shall be removed effectively from the apparatus since a high concentration of oxygen in a confined space can present a fire hazard. 7.1 Stabilizing the equipment 7.1.1 Condition and stabilize the equipment by combusting several samples, similar to those to be analysed (7.4), using appropriate
37、 fluxes and accelerators. NOTEIt is not necessary to use pre-ignited crucibles. 7.1.2 Allow the instrument to cycle several times with oxygen flowing and adjust the instrument zero.EN 27526:1991 4 BSI 10-1999 7.2 Blank test and zero adjustment 7.2.1 Charge a pre-ignited crucible (4.5) with the quant
38、ity of flux and accelerator to be used in the determination (7.4) and add1,00 g of pure nickel of known low sulfur content (4.8). 7.2.2 Place the crucible and contents on the pedestal post of the furnace, raise to the combustion position and lock the system. Operate the furnace in accordance with th
39、e manufacturers instructions. See 9.3 and Annex B. NOTE 1The reading obtained corresponds to the blank due to the crucible, flux, accelerator and sulfur in the pure nickel. NOTE 2The blank should not exceed0,001 % (m/m) sulfur. NOTE 3If the blank reading is abnormally high, investigate and eliminate
40、 the source of contamination. 7.2.3 Adjust the instrument reading using the zero adjust or, on some instruments, the blank offset control, to read the sulfur value of the nickel (4.8). 7.2.4 Repeat 7.2.1 to 7.2.3 to obtain a reproducible reading within the precision limits of the instrument. NOTEAn
41、alternative procedure is to record the reading of the blank test and make the correction using a calibration graph. 7.3 Calibration 7.3.1 Select a certified standard reference steel(4.9). NOTEFor ferronickel, reference materials with a higher sulfur content are used. 7.3.2 Use the certified standard
42、 reference steel in conjunction with pure nickel of low sulfur content0,001%(m/m) which is known or has been determined by ISO7525. 7.3.3 Weigh appropriate proportions of the two materials (7.3.1 and 7.3.2) into a pre-ignited crucible, to cover the high end of the calibration range. Add the preselec
43、ted amounts of flux and accelerator and combust as in 7.2.2. Note the instrument reading. 7.3.4 Adjust the instrument reading to correspond to the correct level of sulfur in the mixture (7.3.3) according to the manufacturers operating instructions. 7.3.5 Repeat 7.3.3 to check the repeatability of th
44、e reading. 7.3.6 Repeat 7.3.3 with different ratios of the reference sample and pure nickel to provide a calibration check over the required range. 7.3.7 Table 1 illustrates the use of the calibration technique using a certified standard reference steel containing0,100%(m/m)S and a reference nickel
45、sample containing0,001%(m/m)S. Table 1 Calibration example 7.4 Determination 7.4.1 Weigh, to the nearest 0,001 g, 0,9 to 1,1 g of the test sample, and transfer to a pre-ignited crucible(4.5) containing a suitable amount of the preferred flux (4.6). Add the appropriate quantity of accelerator (4.7),
46、if required. The flux and accelerator used will depend on the individual characteristics of the equipment and the type of material being analysed. Typical additions to a1,0g test portion are2g of copper,1g of copper plus1g of iron,2 to3g of tungsten, or1g of vanadium pentoxide plus1g of iron powder.
47、 Place the crucible lid in position. 7.4.2 Place the crucible and contents on the pedestal post of the furnace, raise to the combustion position and lock the system. Operate the furnace in accordance with the manufacturers instructions. See 9.3 and Annex B. 7.4.3 Record the analyser reading and repe
48、at the determination. NOTE 1It is important that a high temperature be maintained after the sample is fused to ensure complete transfer of the sulfur dioxide from the furnace to the infra-red analyser. NOTE 2A quiescent combustion is necessary to avoid splashing on to the crucible lid where the fuse
49、d mass may be removed from the induction heating zone. 8 Expression of results 8.1 Calculation 8.1.1 If the instrument has been calibrated to give a read-out directly as a percentage by mass of sulfur with automatic compensation for the mass of the test portion, take the average of the two determinations and report the result. 8.1.2 If the instrument has been calibrated based on a1,00g test portion and does not have automatic mass compensation, divide each reading by the respective mass, in grams, of the test p
