1、CEN ENx2449b 93 3404589 0047082 148 EUROPEAN STANDARD EN 24496 NORME EUROPENNE EUROPISCHE NORM April 1993 UDC 621.762 : 669-492.2 : 620.1 : 543.726 Descriptors: Powder metallurgy, metallic powder, iron, copper, tin, bronzes, chemical analysis, determination of content, acids, insoluble matter Englis
2、h version Metallic powders - Determination of acid insoluble content in iron, copper, tin and bronze powders (IS0 4496 : 1978) Poudres mtalliques - Dtermination de la teneur en insolubles dans les acides pour les poudres de fer, de cuivre, dtain et de bronze (IS0 4496 : 1978) (IS0 4496 : 1978) Metal
3、lpulver - Bestimmung der sureunlslichen Bestandteile in Eisen-, Kupfer-, Zinn- und Bronzepulvern This European Standard was approved by CEN on 1993-04-02. CEN members are bound to comply with the CENCENELEC Internal Regulations which stipulate the conditions for giving this European Standard the sta
4、tus of a national standard 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
5、version in any other language 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,
6、 Greece, Iceland, Ireland, 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 0 1993 Copyrig
7、ht reserved to CEN members Ref. No. EN 24496 : 1993 E CEN EN*2449b 93 9 3404589 O047083 084 Page 2 EN 24496: 1993 Foreword In 1992, IS0 4496 : 1978 Metallic powders - Determination of acid insoluble content in iron, cornie?; tin and brow powders was submitted to the CEN Primary Questionnaire procedu
8、re. Following the positive result of the CEN/CS Proposal IS0 4496 : 1978 was submitted to the CEN Formal Vote. The result of the Formal Vote was positive. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the lat
9、est by October 1993, and conflicting national standards shall be withdrawn at the latest by October 1993. According to the CENKENELEC Internal Regulations, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ire
10、land, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, United Kingdom. CEN EN*2449b 93 = 3404589 0047084 TL0 Density, p 1 SCOPE Concentration of solution This International Standard specifies methods for deter- mining, in iron, copper, tin and bronze powders, the approxi
11、mate content of non-metallic materials which are insoluble in the ordinary mineral acids. The insoluble matter referred to is generally considered to be acid-insoluble silica and silicates, carbides, alumina, clays or other refractory oxides which are either present in the raw material from which th
12、e powders are manufactured or introduced during the manufacturing process. Hydrochloric acid (3.1) Hydrochloric acid (3.2) Potassium thiocyanate (3.3) Nitric acid (3.4) 2 FIELD OF APPLICATION The methods are applicable to lubricant-free metallic powders of iron, copper, tin, alloy bronze and element
13、al mixtures of copper and tin. 1.19 1+1 1.19 1 + 25 1.42 concentrated 5% 3 REAGENTS During the analysis, use only reagents of recognized ana- lytical grade, and only distilled water or water of equivalent purity. See the table for the reagents required. Hydrochloric acid (3.5) Nitric acid (3.6) Hydr
14、ogen peroxide (3.7) Ammonium acetate (3.8) Sodium diethyldithiocarbamate (3.9) Sodium sulphide (3.10) Hydrogen sulphide (3.1 1) Type of powder I Iron 1.19 concentrated 1.42 1+1 30 96 200 911 4% I Copper Tin Bronze Copper Bronze Tin ( Page 3 EN 24496 : 1993 4 APPARATUS Ordinary laboratory apparatus a
15、nd 4.1 Laboratory balance of sufficient capacity and capable of weighing to an accuracy of 5 0,000 1 g. 4.2 Glass filter funnel, diameter approximately 70 mm. 4.3 Filter paper for medium precipitates, diameter approxi- mately 1 1 O mm. 4.4 Furnace, capable of operating between 900 and 1 ooooc. 4.5 F
16、used silica or porcelain crucibles, pretreated to constant mass at 900 to 1 O00 OC and stored in a desiccator. 5 SAMPLING 5.1 Determine the content of insoluble matter on two test portions. 5.2 The massof the test portion shall be approximately 5 9. Reagent CEN ENW449b 93 m 3404589 0047085 957 W Pag
17、e 4 EN 24496 : 1993 6 PROCEDURE 6.1 Iron powder 6.1.1 Weigh, to the nearest 0,000 1 g, a test portion of approximately 5 g of the test sample (mass m, ) and transfer it to a glass beaker. 6.1.2 Carefully add 100 ml of hydrochloric acid (3.1) and cover the beaker with a watch glass. Allow the solutio
18、n to stand at room temperature until the reaction is completed (no further evolution of hydrogen). NOTE - If it is desired to exclude carbides as a part of the insoluble matter, add 20 ml of nitric acid (3.4) to the hydrochloric acid (3.1) used according to 6.1.2. Then proceed according to 6.1.3 to
19、6.1.6. 6.1.3 Place the glass beaker on a hot-plate and heat the solution to boiling. Maintain boiling for about 1 min. Then add 150 ml of water, reheat to boiling and maintain for about 1 min. Allow the solution to cool and settle for 5 min. 6.1.4 Filter the solution through the medium filter paper
20、and wash the residue alternately with hot water and hot hydrochloric acid (3.2). Repeat the washing until iron salts cannot be detected in the washing water, for example by means of potassium thiocyanate (3.3). 6.1.5 Weigh a crucible to the nearest 0,000 1 g (mass m2) and place in it the filter pape
21、r with the residue. Place the crucible on a hot-plate to dry and char the paper. Heat in the furnace at a temperature between 900 and 1000C until the difference between two consecutive weighings of the crucible with the residue after cooling is not greater than 0,000 1 g. Allow the crucible to cool
22、completely in a desiccator. 6.1.6 Determine the mass of the crucible with the residue to the nearest 0,000 1 g (mass m3). 6.2 Tin, copper and bronze powders 6.2.1 Weigh, to the nearest 0,000 1 g, a test portion of approximately 5 g of the test sample (mass m, ) and transfer it to a glass beaker. 6.2
23、.2 Carefully add 50ml of hydrochloric acid (3.51, cover with a watch glass, place on the edge of a hot-plate and digest at low temperature for a minimum of 30 min. 6.2.3 Remove the beaker, cool slightly, cautiously add 50 ml of nitric acid (3.6) and wait for the initial reaction, which starts after
24、about 1 O min. After the reaction is completed, add a further 50 ml of nitric acid (3.6). 6.2.4 Place the beaker on a hot-plate and heat the solution to boiling. Maintain boiling until the volume is reduced to o ne-ha1 f. NOTE - If the residue is black, remove the beaker from the hot- plate, cautiou
25、sly add a few millilitres of hydrogen peroxide (3.7). and boil for 2 min. Repeat the treatment with hydrogen peroxide (3.7) until no black residue is left. 6.2.5 Slowly add 50 ml of hot water and reheat to boiling. Maintain boiling for about 1 min. Allow the solution to cool and settle for 5 min. 6.
26、2.6 Filter the solution through a medium filter paper and wash the residue first with hot hydrochloric acid (3.5) and finally with hot water. Repeat the washing with water until - in the case of copper and bronze powders, copper salts in the washing water cannot be detected, for example by sodium di
27、ethyldithiocarbamate (3.9); - in the case of tin powder, tin salts in the washing water cannot be detected, for example by sodium sulphide (3.1 O) or hydrogen sulphide (3.1 1). NOTE - If the presence of lead sulphate is suspected, wash once or twice with a hot solution of ammonium acetate (3.81 and
28、then with water. 6.2.7 Weigh a crucible to the nearest 0,000 1 g (mass m,) and in it place the filter paper with the residue. Place the crucible on a hot-plate to dry and char the paper. Heat in the furnace at a temperature between 900 and 1 000C until the difference between two consecutive weighing
29、s of the crucible with the residue after cooling is not greater than 0,000 1 g. Allow the crucible to cool completely in a desiccator . 6.2.8 Determine the mass of the crucible with the residue to the nearest 0,000 1 g (mass m3). 7 EXPRESSION OF RESULTS 7.1 The acid-insoluble content, AIC, expressed
30、 percentage by mass, is given by the formula AIC = m3 - m2 x 100 ml where m, is the mass, in grams, of the test portion; as a m2 is the mass, in grams, of the dry, pretreated empty crucible; m3 is the mass, in grams, of the crucible with the residue. 7.2 Calculate the result of each determination to
31、 the nearest 0.01 %. 7.3 The maximum permissible difference between the two determinations shall not exceed 10 % of the mean value or 0,02 % in absolute value, whichever is greater. CEN ENx2449b 93 = 3404589 00470b 893 Page 5 EN 24496 : 1993 7.4 Report the arithmetical mean of the two determi- natio
32、ns rounded to the nearest 0.02 % for contents up to and including 0,25 % and to the nearest 0,05 % for contents greater than 0,25 %. 8 TESTREPORT The test report shall include the following information : a) reference to this International Standard; b) all details necessary for identification of the test sample; c) the result obtained; d) all operations not specified by this International Standard, or regarded as optional; e) details of any occurrence which may have affected the test result.
