ISO-8050-1988.pdf
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1、INTERNATIONAL STANDARD INTERNATIONAL ORGANIZATION FOR STANDARDIZATION OAGANISATION INTERNATIONALE DE NORMALISATION MEXAYHAPOAHAR OPrAHkl3AklR fl0 CTAHAAPTM3AMM Ferronickel ingots or pieces - Sampling for analysis Ferro-nickel en lingots ou en morceaux - . a large block of copper would meet this requ
2、irement. If necessary, the sample shall be killed to obtain a small ingot of sound metal (free of cracks and blowholes). Killing is most often done with aluminium, in wire or chip form, at 1 to 2 g of aluminium per kilogram. The large height of the small ingots permits small shrinkholes to be confin
3、ed to the upper part, thus ensuring that the lower part of the ingot is perfectly sound and homogenous and hence suitable for analysis. Generally, a height of 120 mm will guarantee that the sound portion extends at least 70 mm up from the base. 3.1.2 In general, the small ingots are used for physica
4、l analysis on solid metal after a disc is cut from them. Whenever possible, this analysis should produce results as ac- curate as those obtained from chemical analysis of chips. To achieve such accuracy, it is often necessary to analyse several small ingots several times each. A specified number of
5、small ingots shall therefore be taken at regularly spaced intervals during the casting. Examples are given in annex A to indicate the number of small ingots to be taken and the number to be analysed. It is sug- gested that four to eight small ingots be taken from each heat. 1) This procedure can be
6、applied at the producer s plant, at the buyer s premises or at an intermediate transit place, as agreed between the in- terested parties. 2) Increment: portion of the lot taken in a single operation; in this standard : portion of molten metal. 1 Copyright International Organization for Standardizati
7、on Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/20/2007 02:39:25 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 8050 : 1988 (E) It may happen that for some exceptional reasons there are not enough small ingots
8、 available which are suitable either for ac- curate physical analysis or for accurate analysis of chips taken from them: some small ingots may no longer be available or may contain cracks or blowholes. In these circumstances, the ingots constituting the heat shall be sampled. Five ingots )shall be t
9、aken from the heat, and the procedure described beginning at clause 4.1.3 ) *) shall then be followed. 3.2 Secondary sampling of small ingots taken from the heat 3.2.1 Cutting Each small ingot shall be cut in two about 10 or 15 mm from the bottom (the smaller-diameter end) with a cut-off wheel (made
10、 of Carborundum or corundum, for example). The use of water cooling is recommended, because it avoids heating of the sample and hence changes in the crystalline structure of the metal. 3.2.2 Use of the two pieces of the small ingot 3.2.2.1 The disc cut off the small ingot may be used for physical an
11、alysis (i.e. X-ray fluorescence or optical emission spectrometry) of the solid metal after adequate machining of the cut surface. For the number of small ingots to be analysed and the number of determinations per small ingot, see annex A. 3.2.2.2 The larger piece may be used for preparing chips, usi
12、ng one of the two following methods: a) Drilling With the freshly cut surface facing upwards, the piece shall be drilled to a depth such that the pipe in the upper part of the small ingot (i.e. at the wider end) is not reached. It is desirable to limit the depth of the drilled hole to 50 mm. By usin
13、g a 20 mm diameter drill, more than 100 g of chips are obtained. All the chips shall be collected. An assembly similar to that of figure 1 may be used for this purpose. It is particularly suitable when using a drill bit designed for oil cooling but fed with compressed air (see annex D, D.6.3). The a
14、ssembly shall be made of materials which will not con- taminate the chips. The recommended conditions for drill- ing are described in annex D. b) Milling The conical surface adjacent to the freshly cut surface shall be cleaned by grinding with a corundum (aluminium oxide) or Carborundum grinding whe
15、el and then milled to a depth of about 20 mm from the cut surface (this will provide 100 g of chips). All the chips shall be collected. The recommended conditions for milling are described in annex D. All the chips obtained from the selected small ingots by one of the two techniques described above
16、shall be combined to constitute the secondary sample which is treated according to the procedure in clause 5 to obtain the final laboratory sample. 4 Sampling of a lot of ingots or pieces 4.1 Sampling of ingots or pieces 4.1.1 Lots comprising one heat The procedure as described in the last paragraph
17、 of 3.1 is used (5 ingots or pieces are taken in accordance with the rules for random sampling). 4.1.2 Lots comprising several heats The minimum number Nof ingots or pieces to be taken is given by the following rules3): For lot tonnages between 5 and 80 t N=50 For lot tonnages between 80 and 500 t N
18、 = 54 - f (see footnote 4) where T is the mass, in metric tons, of the lot. 1) The rules for random sampling given in annex 6 may be used. 2) A very small number of ingots constitutes a sufficiently representative sample of the heat, because the contents of different ingots from the same heat do not
19、 vary greatly (see annex C). 3) These rules have been established making the following practical assumptions: - the lots are composed of heats each of mass about 20 t; - the nickel contents of the heats in the lot lie within the range from k to (k + I) %, where k is an integer; - variations in nicke
20、l content within ingots and between ingots from the same heat are negligible compared with the range k to (k + 1) %. Complete justification of these rules is given in annex C. 4) This rule applies only when the tonnage does not exceed 500 t. If, following an agreement between the purchaser and the s
21、upplier, a consign- ment is between 500 and 1 000 t, the interested parties may agree to use one of the following procedures: - division of the consignment into lots of tonnages not exceeding 500 t; - taking, from the whole consignment, only the number of ingots or pieces specified for a tonnage of
22、500 t, i.e. N = 29. This procedure con- siderably diminishes the quantity of work involved in taking secondary samples from ingots or pieces. 2 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resal
23、e, 04/20/2007 02:39:25 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 8050 : 1988 (E) These rules are illustrated in table 1. Table 1 - Number of ingots or pieces to be taken NOTE - Examples of suitable drills, and the conditions under which as a function of lot tonnag
24、e they should be used, are given in annex D. Tonnage T of ferronickel t Number N of ingots or pieces to be taken 5 to 80 50 100 49 140 47 200 44 240 42 300 39 340 37 400 34 440 32 500 29 500t01000 29 The number of ingots or pieces may be increased by agreement between supplier and purchaser. The rul
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