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1、TECHNICAL REPORT ISO/TR 15349-3 First edition 1998-10-15 Unalloyed steel - Determination of low carbon content - Part 3: Infrared absorption method after combustion in an electric resistance furnace (with preheating) Acier non alli - Dgtermination des faibles teneurs en carbone - Partie 3: Methode p
2、ar absorption dans Iinfrarouge apr upport cannot be obtained for the publication of an International Standard, despite - type 2, when the subject is still under technical development or where for any other reason there is the future but not immediate possibility of an agreement on an International S
3、tandard; - type 3 , when a tee hnical committee has collected data of a as an International Standard (“state of the art”, for example) different kind from that which is normally published Technical Reports of types 1 and 2 are subject to review within three years of publication, to decide whether th
4、ey can be transformed into International Standards. Technical Reports of type 3 do not necessarily have to be reviewed until the data they provide are considered to be no longer valid or useful. ISO/lR 15349-3, which is a Technical Report of type 2, was prepared by Technical Committee ISO/TC 17, Ste
5、el, Subcommittee SC 1, Methods of determination of chemical composition. This document is being issued in the Technical Report (type 2) series of publications (according to subclause G.3.2.2 of part 1 of the ISO/IEC Directives, 1995) as a “prospective standard for provisional application” in the fie
6、ld of determination of carbon content in steel because there is an urgent need for guidance on how standards in this field should be used to meet an identified need. This document is not to be regarded as an “International Standard”. It is proposed for provisional application so that information and
7、 experience of its use in practice may be gathered. Comments on the content of those documents should be sent to the IS0 Central Secretariat. A review of this Technical Report (typ e 2) will be carried out not later tha n three years after its publication options of: extension for another three Yea
8、rs; conversion into an I ntern atio nal Standard; or withd rawal. with the lSO/TR 15349 consists of the following parts, under the general title Unalloyed steel - Determination of low carbon content: Part I: Infrared absorption method after combustion in an electric resistance furnace (by peak separ
9、ation) Part 2: Infrared absorption method after combustion in an induction furnace (with preheating) - Pat? 3: Infrared absorption method after combustion in an electric resistance furnace (with preheating) Annex A of this part of ISO/TR 15349 is for information only. Copyright International Organiz
10、ation for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/21/2007 02:41:52 MDTNo reproduction or networking permitted without license from IHS -,-,- This page intentionally left blank Copyright International Organization for St
11、andardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/21/2007 02:41:52 MDTNo reproduction or networking permitted without license from IHS -,-,- TECHNICAL REPORT o Iso ISO/rR 15349-3: 1998(E) Unalloyed steel - Determination of low carb
12、on content - Part 3: Infrared absorption method after combustion in an electric resistance furnace (with preheating) 1 Scope This part of IS0 15349 describes an infrared absorption method after preheating and combustion in an electric resistance furnace for the determination of the low carbon conten
13、t in unalloyed steel. The method is applicable to carbon contents between 0,000 3 % (I e.g. acetone. 4.4 Accelerator, copper plate (see note 1) or granular tin (see note 2) of known very low carbon content less than 0,000 1 % (m/m). NOTE 1 Copper plate (about 0,l g/plate) should be used after the fo
14、llowing treatment: heat the copper plate at 450 OC to 600 OC for IO min in a current of oxygen and cool in a desiccator without grease. This treatment shall be carried out just before use. NOTE 2 Granular tin should be used after the following treatment: rinse the granular tin in hydrochloric acid (
15、p about 1 ,I 9 g/ml, diluted 1 + 1) for 5 min using an ultrasonic wave washer, wash it thoroughly with water and dry. Stock it in a clean glass bottle with ground-in stopper. 4.5 Standard substances 4.51 Sucrose, standard solution Weigh, to the nearest 0,l mg, the masses of sucrose, indicated in tab
16、le 1, (analytical standard grade) previously dried at 100 “C to 105 “C for 2,5 h then cooled in a desiccator and transfer to seven 100 ml beakers. Add 30 ml of water (4.1) to dissolve, transfer to seven 100 ml one-mark volumetric flasks quantitatively, dilute to the mark with water (4.1) and mix. Ta
17、ble 1 - Standard solution series of sucrose Standard solution reference number Mass of sucrose Corresponding mass cl of carbon added I4 0 ) 0,010 0 0,025 0 0,060 0 0,120 0 0,180 0 0,240 0 0 4,21 IO,53 25,26 50,53 75,79 101,l I 1) Zero member. Carbon content in 1 g of the test portion %(mlm) 0 0,000
18、42 0,001 05 0,002 53 0,005 05 0,007 58 0,010 11 4.52 Calcium carbonate Dry calcium carbonate minimum assay 99,9 % (m/m) at 180 OC for 1 h and cool in a desiccator before use. 2 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Sta
19、ndards 1/9972545001 Not for Resale, 04/21/2007 02:41:52 MDTNo reproduction or networking permitted without license from IHS -,-,- 0 IS0 ISO/TR 15349-3: 1998(E) 4.6 Magnesium perchlorate Mg(ClO insert the boat until it is stopped and lock the system. (In this case the centre of boat is at the centre
20、of heating zone - see figure 1). Operate the instrument in accordance with the manufacturers instructions. At the end of the combustion and measuring cycle, remove and discard the boat, and record the analyser reading. 752.3 Plotting the calibration graph Obtain the net reading by subtracting the re
21、ading of the zero member from that of each member of the calibration series. Prepare a calibration graph by plotting the net reading against micrograms, to the nearest 0,l pg, of carbon for each member of the calibration series. 8 Expression of results 8.1 Method of calculation Convert the analyser
22、reading of the test portion to micrograms of carbon by means of the calibration graph (see 7.5). The carbon content, expressed as a percentage by mass, wc, is given by the equation: ( W,l - mc,o WC = ) mx106 x100 ( W,l - mc,o - ) - 104m where rnc 1 I is the mass, expressed in micrograms of carbon, i
23、n the test portion; rnc o , is the mass, expressed in micrograms of carbon, in the blank test (see 7.3); m is the mass, in grams of test portion (see 7.2). 8.2 Precision A planned trial of this method was carried out by only one laboratory, using 11 levels of carbon content as same as described in I
24、SOmf? 15349-1 and IS0 15349-2, however international cooperative tests have not yet been carried out. Therefore precision data cannot be described. 7 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for
25、 Resale, 04/21/2007 02:41:52 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO/TR 15349-3: 1998(E) 0 IS0 Annex A (informative) Features of commercial electric resistance furnaces and infrared carbon analysers A.1 Source of oxygen This is fitted with a fine regulating valv
26、e and a pressure gauge. A pressure regulator is required to control the oxygen pressure to the furnace according to the manufacturers specification. This is usually 28 kN/m*. A.2 Purifying unit This contains the inert ceramic impregnated with sodium hydroxide in a carbon dioxide absorbing tube, and
27、the magnesium perchlorate in a dehydration tube. A.3 Flowmeter This is capable of measuring a flow of oxygen of 0 I/min to 5 I/min. A.4 Electric resistant furnace A.4.1 The combustion furnace consists of a furnace chamber and a heating unit. The furnace chamber consists of a ceramic tube (e.g. 25 mm
28、 to 50 mm in outer diameter, 20 mm to 40 mm in inner diameter and 400 mm to 600 mm in length) which fits inside the heating unit. The tube has metal flanges at the front and rear which are sealed to the tube by the packing. Gas inlet and outlet points are made through the metal plate. A.4.2 The heat
29、ing unit is usually 4 kVA apparent power, and the heating temperature of tube is measured by thermocouple. The tube is resistant up to 1 450 “C. A.4.3 The boat containing the sample and accelerator is inserted at the front of the furnace. The boat should be placed correctly at the centre of the heat
30、ing zone by the inserting rod (rigid nickel bar). The shutter of the furnace should be closed soon after inserting the boat. A.4.4 The temperature attained during combustion depends on the characteristics of the metal in the boat, the form of the test portion and the mass of materials. The importanc
31、e of these factors may be varied to some extent by the operator. Maximum temperature of tube during carbon determination is almost 1 250 OC. A.5 Dust collector This is capable of collecting metal oxide dust in a current of oxygen from the furnace. Copyright International Organization for Standardiza
32、tion Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/21/2007 02:41:52 MDTNo reproduction or networking permitted without license from IHS -,-,- 0 IS0 ISOITR 15349-3: 1998(E) A.6 Desulfurization tube This consists of a heated oxidation tube con
33、taining a platinum foil or platinized silica and a sulfur trioxide collector containing cellulose cotton. A.7 Infrared gas analyser A.7.1 In most instruments the gaseous products of combustion are transferred in a continuous flow of oxygen to the analyser stream. The gases flow through an infrared c
34、ell, for example of the Luft type, where the absorption of the infrared radiation due to carbon dioxide and/or carbon monoxide is measured and integrated over a pre- programmed time period. The signal is amplified and converted to a digital display of the percentage concentration of carbon. A.7.2 In
35、 some analysers, the products of combustion may be collected in oxygen in a fixed volume at controlled pressure and the mixture analysed for carbon dioxide and/or carbon monoxide. A.7.3 Electric controls are usually provided for adjusting the instrument zero, compensating for the blank, adjusting th
36、e slope of the calibration line and correcting for non-liner response. The analyser generally has a means of entering the mass of standard or test portion for automatic correction of the read-out. Instruments may also be equipped with an automatic balance for weighing the boat, weighing the test por
37、tion and transferring the value of mass to the calculator. 9 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/21/2007 02:41:52 MDTNo reproduction or networking permitted without license f
38、rom IHS -,-,- This page intentionally left blank Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/21/2007 02:41:52 MDTNo reproduction or networking permitted without license from IHS -,-,
39、- This page intentionally left blank Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/21/2007 02:41:52 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO/rR 153
40、49-3: 1998(E) 0 IS0 ICS 77.080.20 Descriptors: steels, unalloyed steels, low carbon steels, chemical analysis, determination of content, carbon. Price based on 9 pages Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/21/2007 02:41:52 MDTNo reproduction or networking permitted without license from IHS -,-,-