BS 6200-3 7 1-1987 Sampling and analysis of iron steel and other ferrous metals - Methods of analysis - Determination of calcium - Steel flame atomic absorption spectrometric metho.pdf

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1、8 BSI BS*h200: SUBSEC*3*7-1 O1 E 1624bb9 0278486 7 i - BBU BS 6200 : Subsection 3.7.1 : 1987 EN 10177: 1989 EU 177-1985 A UDC 543.422:546.41:669.14 /d 0 British Standards Institution. No part of this publication may be photocopied or otherwise reproduced without the prior permission in writing of BS

2、I British Standard Sampling and analysis of iron, steel and other ferrous metals Part 3. Methods of analysis Section 3.7 Determination of calcium EU title : Chemical analysis of ferrous materials. Determination of calcium in steels. Flame atomic absorption spectrometric method1 Subsection 3.7.1 Stee

3、l: flame atomic absorption spectrometric method Echantillonnage et analyse du fer, de lacier et dautres mtaux ferreux Partie 3. Mthodes danalyse Section 3.7 Dosage du calcium Sous-section 3.7.1 Acier: mthode par spectromtrie dabsorption atomique Probenahme und Analyse von Eisen, Stahl und anderen Ei

4、senmetallen Teil 3. Analysenverfahren Abschnitt 3.7 Kalzium besti mmu ng Unterabschnitt 3.7.1 Stahl : F iammenatomabsorptionsspektrophotometrie Contents National foreword Method 1. Scope and field of application 2. Reference 3. Principle 4. Reagents 5. Apparatus Page 2 6. Sampling 7. Procedure 8. Ex

5、pression of results 3 9. Test report 3 3 Annex 3 4 Page 4 4 6 6 6 B rit ish Standards I n st it ut ion - - -_ The European Standard EN 10177 : 1989 has the status of a British Standard y BSI BS*b200: SUBSEC*3.7.1 O1 I Lb24669 0278487 7 BS 6200 : Subsection 3.7.1 : 1987 National foreword This Subsect

6、ion of BC 6200 has been prepared under the direction of the Iron and Steel Standards Committee. It is identical with Euronorm 177-1985 Chemical analysis of ferrous materials. Determination of calcium in steels. Flame atomic absorption spectrometric method published by the Commission of the European

7、Communities. In 1989 the European Committee for Standardization (CEN) accepted EU 177-1985 , a calcium 0.00036% and 0.00012% calcium respectively, assuming curve linearity. hollow cathode lamp; supplies of nitrous oxide and acetylene sufficiently pure to give a steady clear fuel-lean flame, free fro

8、m water and oil, and free from calcium 5.1.2 Additional performance requirements The atomic absorption spectrometer used will be satisfactory if after optimization according to 7.3.4 the limit of detection and characteristic concentration are in reasonable agreement with the values given by the manu

9、facturer and it meets the following performance requirements. 5. I. I Minimum precision The standard deviation of IO measurements of the absorb- ance of the most concentrated calibration solution shall not exceed 3Oh of the mean absorbance. The standard deviation of 10 measurements of the absorb- an

10、ce of the least concentrated calibration solution (excluding the zero calibration solution) shall not exceed I% of the mean absorbance of the most concentrated calibration solution. It is also desirable that the instrument should conform to the following additional performance requirements. (a) Char

11、acteristic concentration - The characteristic. con- centration for calcium in a matrix similar to the final test portion solution shall be better than 0.05 ,ug/ml. (b) Limit of detection - The limit of detection of calcium in a matrix similar to the final sample test solution shall be better than 0.

12、025 pghl. 5.2 Ancillary equipment A strip chart recorder and/or digital readout device is recom- mended to evaluate the criteria in 5.1 and for all subsequent measurements. 6. SAMPLING Sampling shall be carried out in accordance with EURO- NOTE - Calcium is liable to non-uniform distribution NORM 18

13、. throughout the steel and it is recommended that the analysis sample should contain not less than 25 g of chips, from which the test portion (7.1) shall be drawn. Degrease the chips with ethyl ether. avoiding contamination of the sample when handling. 7. PROCEDURE NOTE - All glassware shall first b

14、e washed in dilute hydro- chloric acid and then in water. The quantity of calcium the glassware after the acid wash. present in the beakers and the flasks can be checked by measuring the absorption of the distilled water introduced into 4 BSI BS*:b200: SUBSEC*3.7-1 O1 = 1b24669 0278492 2 7.1 Test po

15、rtion Weigh the mass (rn) indicated below to the nearest 0.00 I g: Il1 = 2g : I“. 7.2 Blank test With each analytical run, carry out an analysis on a reagent blank in parallel with the test portion analysis, using identical reagents. conditions. analytical procedures and dilutions throughout. 7.3 De

16、termination 7.3. I Preparation of the test solution Place the test portion (7. i) in a 400 ml beaker. Add 20 ml of hydrochloric acid (4.2). Heat gently until the reaction ceases. Oxidize with 5 ml nitric acid (4.3). Boil the solution for 5 minutes to remove oxides of nitrogen. Cool, transfer the sol

17、ution to a 100 ml volumetric flask. Do not filter unless absolutely necessary. If unavoidable, use only filters known to be free of calcium. Add 0.5 ml of potassium chloride soiution (4.4). dilute to the mark with water and mix. For test solutions giving a calcium absorbance in excess of about 0.6,

18、the solution must be diluted (dilution factor D) and compared with calibration solutions prepared and diluted with the same iron and reagent concentrations. These more dilute solutions should also be employed if problems with burner blockage are encountered. 7.3.2 Preparation of the calibration solu

19、tions Place IO g of iron (4. i) in an 800 ml beaker and add 100 ml of hydrochloric acid (4.2). Heat gently until the reaction ceases. Oxidize with 25 ml of nitric acid (4.3). Boil the solution for 5 minutes to remove oxides of nitrogen. Transfer to a 200 ml volumetric flask, add 2.5 ml of potas- siu

20、m chloride solution (4.4), dilute to the mark with water and mix. Transfer a series of 20.0 ml aliquots to 50 ml volumetric flasks. For a calibration graph to cover the range up to 0.006% calcium add to each flask from a burette or pipette O, 5.0. 10.0. 15.0, 20.0, 25.0; and 30.0 ml of calcium refer

21、- ence solution II (4.7). dilute to the mark with water and mix. For calcium levels above 0.006% suitable aliquots of calcium reference solutions I (4.6) and II (4.7) should be used to give a range of calibration solutions with the highest level of calcium approximately twice that of the sample. NOT

22、E - I ml of calcium reference solution I (4.6) is equiva- lent to 0.002% calcium in the sample. 7.3.3 Adjustment of atomic absorption spectrometer (5. i) Type of lamp: Wavelength: 422.67 nm. Flame: Nitrous oxide/acetylene fuel-lean Calcium hollow cathode. flame adjusted for maximum calcium response.

23、 Lamp current - Slit width: Follow manufacturers recommendations. BS 6200 : Subsection 3.7.1 : 1987 NOTE - The manufacturers recommendations should be closely followed and particular attention is drawn to the following safety points: (a) the explosive nature of acetylene and regulations concern- ing

24、 its use; (b) the need to shield the eyes of the operator from UV radiation by means of tinted glass; (c) the need to keep the burner head clear of deposits, A badly clogged burner may cause a flashback; (d) make sure the liquid trap is filled with water. . 7.3.4 Optimization of the atomic absorpfio

25、n spectrometer settings Follow the manufacturers instructions for preparing the in- strument for use. When the current to the lamp, the wavelength and the flow of gas have been adjusted and the burner lit, spray water until the indication has stabilized. Set the absorbance value to zero. Choose a da

26、mping setting or integration time to give a signal steady enough to fulfil the precision requirements (5. I. I). Adjust the flame to be fuel-lean and the burner height to about 1 cm below the light path. Spraying, alternately, the high and zero calibration solutions, adjust the gas flow and the burn

27、er positior? (horizontally, vertically and rotationally) until the difference in absorbance between the calibration solutions is at a maximum. Evaluate the criteria of 5. I. I to ensure that the instrument is suitable for the determination. 7.3.5 Atomic absorption measurements Set the scale expansio

28、n so that the top calibration solution gives nearly full-scale deflection. Aspirate the calibration solu- tions in ascending order repetitively until each gives accept- able precision (see 5.l.l), thus showing that the instrument has achieved stability. Select two calibration solutions, one having a

29、n absorbance just lower than the test solution and one just higher. Aspirate these first in ascending order. then in descending order, with the test solution as the middle solution in each case, measuring the absorption in relation to water. Aspirate the complete range of calibration solutions again

30、. It is recognized that these procedures cannot be followed with automatic instruments which accept two calibration solutions only. in this case, it is suggested that the two sandwiching solutions should not be used for the primary calibration but should be analysed alternately with the test solutio

31、n. Obtain the net mean absorbance of each calibration solution by subtracting the mean absorbance of the zero calibration solution. Obtain the mean absorbance of the test solution and the mean absorbance of the reagent blank solution. Convert the mean absorbances of the test solution and of the reag

32、ent blank solution to micrograms of calcium per millilitre by means of the calibration graph (7.4). 7.4 Establishment of the calibration graph It is necessary to draw up a new calibration graph for each series of determinations, and for the range of calcium contents expected. . 5 . BSI BSU620O: SUBS

33、EC*3-7.1 O1 E 1624669 0278493 4 111 Alloy Type 0.33% C free-cutting 0.36% C steels with 0.43% C 1.4% Mn, 0.25% S 1 BS 6200 : Subsection 3.7.1 : 1987 Repeaiabiliry Reproducibilii y r R Calcium Y m/m) 0.00030 0.OOO I7 0.00025 0.00 I25 0.00020 0.00023 0.00326 0.00025 0.00048 Prepare a calibration graph

34、 by plotting the net mean absor- bance values of the calibration solutions aga;.d micrograms of calcium per millilitre. Refer the net absorbances of the two adjacent calibration solutions to the graph. If these two calibration readings do not deviate from the graph by more than the permitted precisi

35、on criteria then the test solution readings are acceptable. 8. EXPRESSION OF RESULTS The percentage by rnas of calcium (Ca) is given by the expression pressed in pg/ml Ca “,n (mim) = b is the concentration of calcium in the test solution ex- c is the concentration of calcium in the reagent blank sol

36、ution D is the dilution factor applied in Section 7.3.1 rn is the mass. in g of the test portion expressed in pg/ml (b - C) D 100 100 (b - C) * D .- - 1 O6 rn 100 rn u here : 9. TEST REPORT The test report shall contain the following particulars: (d) any operations not specified in this EURONORM or

37、any . (a) the method of analysis used by reference to this EURO- NORM: optional operations which could have had an influence on the results; (e) all indications necessary for the identification of the (b the results obtained. as well as the form in which they are sample: expressed: (f) the laborator

38、y and the date of analysis. (c) an) particular details which may have been noted during the determination: ANNEX Precision data Planned trials of this method were carried out by 3 analysts from different laboratories: IO determinations were carried out by each analyst on each of 3 samples. From the

39、results obtained the 95% (2s) confidence limits have been calculated in accordance with IS0 5725, and are tabulated as follows: In addition, the method was also tested by 13 laboratories on EURONORM CRM 252-1, a high chromium-nickel-moly- bdenum stainless steel. with results varying from 0.0015% to

40、0.0020%. and with a repeatability of 0.0001% within each labora tory. Repeatability The difference between two single results found on identical material by one analyst using the same apparatus within a short time interval will exceed the repeatability, r, not more The difference between two single

41、and independent results found by two operators working in different laboratories on identical test material will exceed the reproducibility. R. on average not more than once in 20 cases in the normal and correct operation of the method. 6 than once in 20 cases in the normal and correct operation of

42、the method. Reproducibility Publications referred to See national foreword. BSI BS*b2OO: SUBSECx3.7.1 O1 I 1b24bb7 0278475 8 U Arnd. No. BS 6200 : Subsection 3.7.1 : 1987 EN 10177 : 1989 EU 177-1985 a v, Date of issue Text affected 03r WCD “Sz: *2 This British Standard, having been prepared under th

43、e direction of the Iron and Steel Standards Committee, was published under the authority of the Board of BSI and comes into effect on 31 July 1987. British Standards Institution, 1987 ISBN O 580 15980 9 The following 8SI references relate to the work on this standard: Committee reference ISM/18 Draf

44、t for comment 82/71475 DC Am end ment c issued si n ce DU b I i ca t i o n British Standards Institution . 2 Park Street London W1A 2BS a Telephone 01-629 9000 . Telex 266933 8707 -3-1.4k-B BSI BS*h200: SUBSEC*3*7-L OL = Lb24669 0278Y9b T W Amendment No. 1 published and effective from 28 February 19

45、92 to BS 6200 : Subsection 3.7.1 : 1987 Sampling and analysis of iron, steel and other ferrous metals Part 3. Methods of analysis Section 3.7 Determination of calcium Subsection 3.7.1 Steel: flame atomic absorption spectrometric method AMD 7069 NOTE. The European Committee for Standardization (CEN)

46、has accepted Euronorm 177-1985 as a European Standard designated as EN 10177 : 1989. This amendment implements EN 10177 : 1989 as a British Standard. Revised text AMD 7069 February 1992 Front and back covers In the top right-hand corner of the front cover and twice on the back cover, immediately abo

47、ve EU 177-1985, insert EN 10177 : 1989. Delete the existing UDC number on the front cover and substitute UDC 543.422:546.41:669.14. At the foot of the front cover insert the following. The European Standard EN 10177 : 1989 has the status of a British Standard. AMD 7069 Februnry 1992 National forewor

48、d At the end of paragraph 2 insert the following new paragraph. In 1989 the European Committee for Standardization (CEN) accepted EU 177-1985 as European Standard EN 10177 : 1989. Delete paragraphs 3 and 4 entirely. AMD 7069 February 1992 New EN title page and brief history Immediately after the nat

49、ional foreword, insert the attached new EN title page and brief history page. ISW18 9202-24.5k-B LUROPEAN STANDARD NORME EUROPEENNE EUROPISCHE NORM EN 10177 January 1989 UDC 543.422:546.41:669.14 Descriptors: Iron and steel products, steels, chemical anaiysis, determination of content, molecular absorption spectrophotometry, tiame photomefxy English vemion Chemical analysis of ferrous materials Determination of dciurn in steels Fhrne atomic absorption spectrometric method Analyse chimique des matriaux sidrurgiques - Dosage du calciu