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1、BRITISH STANDARD BS ISO 13807:1999 Incorporating Technical Corrigendum No.1 Vitreous and porcelain enamels Determination of crack formation temperature in the thermal shock testing of enamels for the chemical industry ICS 25.220.50 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT L
2、AW Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 11:39:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 13807:1999 This British Standard, having been prepared under the direction of the Sector Committee for Materials and Chemicals, was published under the authority of the Standards Comm
3、ittee and comes into effect on 15 February 2001 BSI 07-2001 ISBN 0 580 34030 9 National foreword This British Standard reproduces verbatim ISO 13807:1999, including technical corrigendum November 2000, and implements it as the UK national standard. The UK participation in its preparation was entrust
4、ed to Technical Committee STI/36, Vitreous enamel coatings, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in
5、 this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract.
6、Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretatio
7、n, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the ISO title page, pages ii and iii, a blank page, pages 1 to 6, an i
8、nside back cover and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. DateComments 13024 Technical Corrigendum July 2001Indicated by a sideline Licensed Copy: sheffieldun sheffieldun, na, Sun Nov
9、 26 11:39:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Reference number ISO 13807:1999(E) INTERNATIONAL STANDARD ISO 13807 First edition 1999-12-01 Vitreous and porcelain enamels Determination of crack formation emperature in the thermal shock testing of enamels for the chemical industry maux vitri
10、fis Dtermination de la temprature de fissuration par choc thermique dmaux pour lindustrie chimique Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 11:39:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 13807:1999(E) ii Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 11:39:42 GMT+00:00
11、 2006, Uncontrolled Copy, (c) BSI ISO 13807:1999(E) iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees
12、. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the Intern
13、ational Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3. Draft International Standards adopted by the technical committees are circulated to the member bodie
14、s for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of patent rights. ISO shall not be held responsible for ide
15、ntifying any or all such patent rights. International Standard ISO 13807 was prepared by Technical Committee ISO/TC 107,Metallic and other inorganic coatings. Annex A of this International Standard is for information only. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 11:39:42 GMT+00:00 200
16、6, Uncontrolled Copy, (c) BSI Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 11:39:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI INTERNATIONAL STANDARDISO 13807:1999(E) 1 Vitreous and porcelain enamels Determination of crack formation temperature in the thermal shock testing of enamels for t
17、he chemical industry 1Scope This International Standard specifies a test method for the determination of the crack formation temperature of enamels for the chemical industry by subjecting enamelled steel specimens to thermal shock using cold water. The value of the crack formation temperature measur
18、ed according to this test method is not valid for the finished component (see annex A). It is a parameter of vitreous and porcelain enamels for comparing the relative quality of different enamel formulations. 2Normative references The following normative documents contain provisions which, through r
19、eference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of a
20、pplying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 2746,Vitreous and porcelain enamels Enamell
21、ed articles for service under highly corrosive conditions High voltage test. ISO 2808,Paints and varnishes Determination of film thickness. IS0 3819,Laboratory glassware Beakers. ISO 10141,Vitreous and porcelain enamels Vocabulary. 3Terms and definitions For the purposes of this International Standa
22、rd, the terms and definitions given in ISO 10141 as well as the following apply. 3.1 crack formation temperature thermal shock temperature at which the first damage to the enamel occurs in the form of cracks and/or chipping 3.2 thermal shock temperature temperature of the specimen immediately before
23、 quenching with cold water Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 11:39:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 13807:1999(E) 2 4Designation The test method for the determination of the crack formation temperature of enamels for the chemical industry by the thermal shock te
24、st described in this Intemational Standard is designated as follows: Test ISO 13807 5Principle The specimen is heated to the thermal shock temperature in a drying oven. After reaching the thermal shock temperature, the enamelled surface is covered by water at a temperature between 10 C and 30 C. The
25、n the specimen is dried and visually examined for damage. To make cracks visible, the entire enamel surface is sprayed with electrostatically charged talcum powder. If no damage to the enamel is found after the first thermal shock test, the test shall be repeated at a thermal shock temperature 10 C
26、higher than in the previous test. 6Apparatus 6.1Drying oven, capable of maintaining temperatures of at least 300 C. 6.2Low-form beaker, having a capacity of 2 000 ml meeting the requirements of ISO 3819. 6.3Spray gun, equipped with a hard-rubber nozzle for electrostatically charging the talcum powde
27、r. 7Specimens 7.1Shape and preparation of specimens Specimens shall be square sheet metal plates with a thickness of at least 10 mm and an edge length of 150 mm that have been enamelled on one side. Alternatively, specimens as shown in Figure 1 made of 10MnTi3 low-alloyed enamelling structural steel
28、 may be used. The steel shall have the following nominal composition (% mass fraction): ?carbon, u 0,12 %; ?manganese, 0,40 % to 1,00 %; ?titanium 0,10 % to 0,16 %; ?phosphorus u 0,035 %; ?sulphur, u 0,030 %. During the enamelling process, these specimens shall be held in the horizontal position by
29、means of a rod inserted in the 5 mm hole. The ground coat shall cover the entire surface. The cover coat may be applied only to the top and convex surface (radius 8 mm). NOTEBesides the determination of crack formation temperature, enamelled specimens shown in Figure 1 may also be used for corrosion
30、 tests in closed systems according to ISO 13806. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 11:39:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 13807:1999(E) 3 Dimensions in millimetres Roughness values in micrometres Figure 1 Steel specimen for determination of the crack formation t
31、emperature of enamels by thermal shock Prepare the specimens by the same enamelling process used for the enamelled product, including the pretreatment, type of ground and cover coat, application technique, firing temperature and thickness of the ground coat. After each firing step, the specimens are
32、 removed from the oven and may be cooled in air. However, the specimens shall be submitted to controlled cooling after the last coating or directly after the last firing. Heat the specimens up to 800 C in an oven, maintain this temperature for at least 20 min, then cool to , 250 C at a cooling rate
33、of u 1 C/min (see annex A). The overall thickness of the enamel measured by the method given in ISO 2808 shall be between 0,8 mm and 1,4 mm. The finished enamel coating shall be free from defects. This shall be checked visually, as well as with the high voltage test at 12 kV described in ISO 2746. S
34、pecimens of other shapes or manufacture may be used, when specified by the purchaser. The use of specimens having different shapes or manufacture shall be noted in the test report. 7.2Number of specimens Two specimens of the same type shall be used for each determination. 8Procedure 8.1Place the two
35、 enamelled specimens with the enamelled surface upwards in the drying oven (6.1) heated to the thermal shock temperature. The thermal shock temperature shall be about 20 C below the expected crack formation temperature. If necessary, determine the crack formation temperature by a preliminary test. 8
36、.2Determine by a preliminary test, the time span necessary for heating the specimens to the thermal shock temperature. After the specimens have reached the thermal shock temperature, open the drying oven (6.1) and remove one specimen by means of a fork or other tool, without touching the enamel surf
37、ace. Hold the specimen horizontally and cover the centre of it by pouring 2 I of water at a temperature between 10 C and 30 C, pouring the water at a rate of approximately 100 ml/s. From the moment the drying oven (6.1) is opened until the cold water is poured on to the specimen, no more than 3 s sh
38、all elapse. 6u Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 11:39:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 13807:1999(E) 4 8.3After the first specimen has been removed from the drying oven (6.1), leave the second specimen in the oven until it has again reached the thermal shock te
39、mperature, plus an additional 5 min. Then repeat the thermal shock step with the second specimen, by the procedure described in 8.2. 8.4Check the dried specimens visually for damage to the enamel. To make cracks easier to detect, spray the enamel with electrostatically charged talcum powder using th
40、e spray gun (6.3). This technique will make even fine cracks easy to detect. 8.5If no damage to the enamel is detected on one or both specimens after the thermal shock test, repeat the test on the same specimens at a thermal shock temperature that is 10 C higher than in the first test. 8.6If the dif
41、ference in the crack formation temperature as determined by the above procedure is greater than 10 C, the test shall be repeated with two new specimens. 9Expression of results Average the crack formation temperatures that do not differ by more than 10 C. 10 Test report The test report shall include
42、the following information: a)the type of enamel tested; b)the designation (see clause 4) of this test method, i.e. Test ISO 13807; c)the thickness of the enamel coating; d)the material code or designation of the basis metal; e)if applicable, the shape of the specimen, if specified by the purchaser (
43、see clause 7); f)the description of the damage to the enamel coating; g)the individual values of the crack formation temperatures, in C; h)the arithmetic mean of the crack formation temperature, in C. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 11:39:42 GMT+00:00 2006, Uncontrolled Copy,
44、(c) BSI ISO 13807:1999(E) 5 Annex A (informative) Explanatory notes In the case of vitreous enamelling, the two components, enamel and metal, are firmly fused together by means of a mechanical and chemical bond. As a result of the different thermal expansion and softening characteristics of enamel a
45、nd metal, temperature-dependent stresses develop in the composite. The components of the composite are generally designed such that compressive stresses are present in the melted-on enamel coating. In the case of vitreous enamelling, four different types of thermal shock are known: a)cold-shock on t
46、he enamel side; b)heat shock on the metal side; c)heat shock on the enamel side; d)cold shock on the metal side. Since cold shock on the enamel side with cold water is the most critical type, this test is specified in this International Standard. The crack formation temperature of enamel as determin
47、ed by thermal shock testing is a characteristic of the composite material. No conclusions should be drawn from the results of this thermal shock test about the resistance to cold of an enamelled product. In practice, the crack formation temperature is influenced by stresses due to manufacture, that
48、originate from welded joints or from non-uniform cooling from the enamelling temperature. The crack formation temperature is also influenced by mechanical deformation occurring after enamelling as a result of welding on the double jacket of the vessel or by support forces introduced by the container
49、 support structure. In addition, stresses during service that occur at a particular production stage, e.g., compressive stress on the inner vessel or jacket, may affect the crack formation temperature. Consequently, the thermal shock resistance guaranteed by the enamel manufacturer for the enamelled product will always be considerably lower than the crack formation temperature determined in accordance with this International Standard. The controlled cooling of specimens after enamelling (see 7.1) reduces the stresses that are created by uncontroll
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