1、CEN EN*LO*03b 89 m 340q58 OOOOL38 O m EUROPEAN STANDARD NORMEEUROPENNE EUROPIUSCHE NORM EN IO036 January 1989 LDC 669.1:542.26:543.21 Key words : Iron- and steel products; steels; cast iron; chemical analysis; determination of content; carbon; gravimetric analysis; combustion analysis; English versi
2、on Chemical analysis of ferrous materials Determination of total carbon in steels and irons Gravimetric method after combustion in a stream of oxygen Analyse chimique des matriaux Chemische Analyse von Eisen- und sidrurgiques - Dosage du carbone Stahlwerkstoffen - Ermittlung des total dans les acier
3、s et les fontes Gesamtkohlenstoffgehalts von Stahl Mthode gravirntrique aprs combustion und Roheisen - Gewichtsanalytische dans un courant doxygne Ermittlung nach Verbrennung im Sauerstoffstrom This European Standard was accepted by CEN on 89-01-15 . CEN members are bound to comply with the requirem
4、ents of the CEN/CENELEC Rules whichstipulate 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 stan- dards may be obtained on application to the CEN Central Secretariat o
5、r to any CEN member. This European Standard exists in the official versions (English, French, Ger- man). A version in any other language made by translation under the responsi- bility of a CEN member into its own language and notified to CEN Central Sec- retariat has the same status as the official
6、versions. . CEN members are the national standards organizations of Austria, Belgium, Denmark, Finland , France, Germany, Greece, Iceland, Ireland, Italy, Luxemburg, Netherlands Norway, Portugal , Spain, Sweden , Switzerland and United Kingdom. CEN European Coiittee for Standardization Comit Europen
7、 de Normalisation Europisches Komitee fr Normung Central Secretariat : Rue Brderode 2, B-1000 Brussels CEN 1989 Copyright reserved to all CEN members Ref.No. EN 10 0361989 E CEN EN*LO*O3b 87 3L109589 0000137 2 EN 10 036 Pae 2 Brief History This European Standard takes over the content of 3URONOR.I 3
8、6-83 “Chemica: analysis of ferrous materials - Determination of total carjon in stees and irons - Gravimetric method after combustion in a stream of oxygen“, prepared by ECISS/TC 20 “Methods of chemica, analysis“; the Secretariat of which is allocated to the Dansk Stanciardiseringsrad (DS). It has b
9、een submitted to the CEN Formal Vote following the decision of the Coordinating Commission (COCOR) of the European Committee for Iron and Steel Standardization on 1987-i1-24/25. it has been adopted and ratified by CEN BT on 1988-11-05. According to the Common CEN/CENELEC Rules, following countries a
10、re bound to implement this European Standard : Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxemburg, Netherlands, Norway, Portugal , Spain, Sweden, Switzerland and United Kingdom. Note in clauses 1 and 9 EURONORM shall read EUROPEAN STANDARD. CEN EN*K10*03b
11、 87 3LiOL1589 OOOOL40 7 EN 10 036 Page 3 Chemical analysis of ferrous materials Determination of total carbon in steels and irons Gravimetric method after combuson in 8 stteam of oxygen CONTENTS I SCOPE AND FIELD OF APPLICAIION 7 PROCEDURE 2 REFERENCE 3 PRINCIPLE 4 REAGENTS 5 APPARATUS 6 SAMPLING 7.
12、1 Test portion 7.2 Blank test 7.3 Determination 8 EXPRESSION OF RESULTS 9 TEST REPORT 1 SCOPE AND FIELD OF APPLICATION This EURONORM specifies a gravimetric method for the determination of total carbon in steels and irons after combus- tion in a stream of oxygen. “he method is applicable to carbon c
13、ontents equal to or greater then 0.1% (m/m). 2 REFERENCE EURONORM 18.;)rSelection and preparation of samples and test pieces for stecl and iron and sal products. 3 PRINCIPLE Combustion of a test portion in a stream of oxygen in a high temperature furnace (1 200- i WC), with the addition of a fluxing
14、 agent to assist combustion. Absorption of the evolved carbon dioxide in soda askstos contained in a weighed rbsorption bulb. Calculation of the carbon content from the increase in mass of the absorption bulb. 4 REAGENTS During the anaiysis, use only teagmts o recognized anaiyti- cai quality. 4. i O
15、xygen, cymer oxygm, of it ieut 99% purity. 4.2 Magnesium perchlorate (Anhydmne) u a drying agent. 4.3 Fluxes: lead oxide, copper (II) oxide, tin filings; high punty iron chips of certified very low cubon content. 4.5 Sodr wkstos, in gruruies of approximately 2 mm diameter, Avoid Contact with lit. Ha
16、ndiing of this reagent should uke place under a fume hood with suficient suction to avoid inhrlrtion of ubs dust by the operator. 4.6 Sdphuric acid, p 1.84 g/mi approximately, (I 8 moVI approximately). 4.7 Chd-sulphuric acid; Saturate L suiphunc acid . 4.4 Copper (II) oxide, granuiated. soution, p 1
17、.23 ippmximrtdy (4 mdi approximately) With chromic acid anhydride (CIO,). The solution remains effective only u long u it reuins its ted colour. Sulphuric EN 10 036 Page 4 CEN EN*10*03b 89 3404589 O000141 O 5 APPARATUS The apparatus consists of three parts: The first part includes the oxygen cylinde
18、r and the oxygen-purifier, the second part comprises the furnace and combustion tube and the third part comprises the vessels for purification and absorption of the carbon dioxide produced by combustion of the carbon in the analysis sample. The three pans. which arc interconnected by tubing and her-
19、 metically sealed stoppers. are depicted in Fig. I, Fig, 1 Oxygen cylinder (4.1) with a pressure regulating valve. Mercury valve. Furnace with non-porous porcelain tube, heated to 4WC, containing granules of copper (II) oxide (4.4). U tube containing magnesium perchlorate (4.2) and soda asbestos (4.
20、5) separated by glass wool for drying and purification of oxygen (diameter of the tubes is 25 mrn. height approximately 100 mm with connection). The U tube must be packed in such a manner that the oxygen passa fust through the soda asbestos and afterwards through the magne- sium perchlorate. Elecuic
21、 resistance furnace, caprbie of raising the temperature of the combustion tube to 14“C. Thermocouple for temperature measurement. The point of the thermocouple protected by its own sheath is placed near the external surface of the combustion tube. It is recommended that the Merence between the exter
22、nal and the internal tanperatw o the tube should be checked. Refractory combustion tube which is not porous at the test temperature. having an intanal diuneter of H IJ L M M N 0,O O“ P 20 to 30 mm and a length of at least 600 mm so that the ends of the tube remain cool during the combus- tion. The t
23、ube should extend beyond each end of the furnace by not less than IS0 mm. Refractory boat with eydet (length 80 to 100 mrn. width I2 to 14 nun, height 8 to 9 mm) calcined in a current of oxygen und the working conditions. Small, porous refractory cylinders for protecting the end stoppen of the combu
24、stion tube against the heat. For subsequently cooling the tube. its ends can be enclosed by water-circulating lead or copper coils. Glass bulb tube filled with quartz wool to trap the dust carried along by the gas flow. Wash bottle containing the chromic-sulphuric acid Drier containing the magnesium
25、 perchlorate (4.2). Contact furnace with non-porous porcelain tube. heated to 4oooC containing copper (II) oxide gran- ules (4.41, in order to ensure complete oxidation to carbon dioxide. Weighed absorption bulbs with turn off taps. for the absorption of the carbon dioxide, containing soda asbestos
26、(4.5) and a layer (10-20 mm) of magnesium perchlorate (4.2) for retaining the water formed during the absorption of the carbon dioxide. The total mass of each absorption bulb, ready for use. should not exceed 100g (set Fig. 2). Unweighed absorption bulb, facing the opposite way to O and O. Bottle of
27、 sulphunc acid (4.6) for the protection of the absorption bulbs against the outside atmosphere and also for monitoring the rate of the oxygen flow. (4.7). ) 6 SAMPLING Sampling shall be clmed out in accordance with EURO- NORM 18: 79 The sample as prcpwd for analysis shd h, in the form of very short
28、chips having a thickness not exceeding 8 few tenths of a miltimetre. For white cut irons the analysis sample must be fine enough to pw through a sieve of O. I8 mm mesh sire. For grey cut irons the test piece shhrll be cut into plates 2 mm thick d broken up with plia to avoid the possibility of erron
29、 arising from the segregation of graphite. 7 PROCEDURE After checking the leak-tightness of the apparatus and having attained a temperature of 1 200-1 4000C in the combustion zone of the furnace (use highest temperature for the more .highly alloyed steels), aiiow the oxygen (4, i) to flow into the a
30、pparatus for 10 to IS minutes, at a rate of 300 to 500 ml per minute depending on the diameter of the tube used. Next disconnect the absorption bulbs and close the taps to avoid contact with ambient air. Weigh than after IO minutes at ambient temperature and then reconnect them to the appa- ratus. 7
31、.1 Test portion Weigh the muses (m) given below as a function of presumed carbon content to the nearest 0.001 g remaining within the tolerance of +1% of the specified mass: (a) content from 0.1% to 196 m approximately 2 g: (b) content above 136, m approximately I g. Transfer the waghed test ponion t
32、o the calcined refractory boat Add to the umple 1 to 2 g of carefully weighed flux (4.3). CEN EN*KL*O3b 69 W 3404589 OOOOL42 2 m EN io O36 Page 5 7.2 Blank test Determine the blank value of the apparatus. boat and flux by combustion of the boat containing the prescribed quantity of flux (4.3) exactl
33、y in accordance with the conditions specified for the analysis (7.3) and record the increase in mass (mass mo) of the absorption bulb. Where there is any doubt about the purity of the boat. this should be verified by the combustion in the boat of the exact amount of flux used in the analysis, togeth
34、er with 1 g of high purity iron of certified very low carbon content (4.3). Iri this case, the blank value (mass mo) is obtained ater correcting for the certified carbon content of the high punty iron. The leak-tightness of the apparatus and the effectiveness of the purification system can be checke
35、d without submitting materials and fluxes to combustion. 4 7,3 Determination Cut off the oxygen flow. then open the cornbustion tube at the end where the oxygen enters and introducc the boat with the sample into the middle of the heated zone of the tube by means of a rigid nickel rod. Close the tube
36、 immediately and after one minute allow an oxygen flow to pass through at a rate of 300 to 500 ml per minute depending on the diameter of the tube used. Combustion should be complete after approximately 2 min- utes but continue the oxygen flow for a funher 15 to ?O minutes to ensure the complete exp
37、ulsion of the carbon diox- ide from the combustion tube and the purification bulbs. Cut off the oxygen flow, close the taps of the weighed absorption bulbs and remove the refractory boat from the combustion tube. Check whether the combustion has been properly carried out by examining the fused mass
38、in the boat withdrawn from the furnace. Complete combustion is indi- cated by a totally fused mass in which no traces of the original sample can be recognized Disconnect the absorption bulbs and after 10 minutes weigh them at ambient temperature. The increase in mass represents the carbon dioxide ab
39、sorbed (mass m,). 8 EXPRESSION OF RESULTS The percentage by mass of carbon (C) is given by the expres- sion: where m, is the mass of carbon dioxide from the test sample. in mo is the mass of carbon dioxide from the blank test, in g: m is the mass of the test portion, in g; 27.29 is the conversion fa
40、ctor of carbon dioxide to carbon, multiped by 10. (m, - mo) x 27.29 m c96 = 9 TEST REPORT The test report shall contain the following particulars: (a) the method of analysis used by reference to this EURO- NORM; (b) the results obtained, as well as the form in which they are expressed: result. (c) any panicuar details which may have bn noted during the determination: (d) any operations not specified in this EURONORM or any optiond operations which could have had an influence on the ,CEN EN*LO*O3b 89 m 3404589 OOOOL43 4 m EN i0 036 Page 6 R
