1、BRITISH STANDARD BS 1344-21: 1993 ISO 4532:1991 Methods of testing Vitreous enamel finishes Part 21: Determination of the resistance of vitreous enamelled articles to impact: pistol test UDC 666.293:620.178.7BS1344-21:1993 This British Standard, having been prepared under the directionof the Surface
2、 Treatments and Coatings Standards Policy Committee, waspublished under the authorityof the Standards Boardand comes into effect on 15October 1993 BSI 07-1999 The following BSI references relate to the work on this standard: Committee reference STC/36 Draft for comment 90/50820 DC ISBN 0 580 22335 3
3、 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Surface Treatments and Coatings Standards Policy Committee (STC/-) to Technical Committee STC/36, upon which the following bodies were represented: Agricultural Engineers Association Assoc
4、iation of Manufacturers of Domestic Electrical Appliances British Bathroom Council British Steel plc Insitute of Vitreous Enamellers Metal Sink Manufacturers Association Ministry of Defence Vitreous Enamel Development Council Amendments issued since publication Amd. No. Date CommentsBS1344-21:1993 B
5、SI 07-1999 i Contents Page Committees responsible Inside front cover National foreword ii 1 Scope 1 2 Normative reference 1 3 Principle 1 4 Apparatus 1 5 Test specimens 1 6 Procedure 2 7 Expression of results 2 8 Test report 2 Annex A (informative) Calibration and determination of the zero point oft
6、heapparatus 3 Annex B (informative) Bibliography 4 Figure 1 Test apparatus 1 Figure A.1 Graph for the determination of the zero point of two differentapparatuses 3 Table A.1 Values obtained for two different apparatuses when testedaccording to A.1 3 List of references Inside back coverBS1344-21:1993
7、 ii BSI 07-1999 National foreword This Part of BS 1344 has been prepared under the direction of the Surface Treatments and Coatings Standards Policy Committee and is identical with ISO4532:1991 Vitreous and porcelain enamels Determination of the resistance of enamelled articles to impact Pistol test
8、, which was prepared by Technical Committee TC 107, Metallic and other non-organic coatings, of the International Organization for Standardization (ISO), with the active participation and approval of the UK. Further Parts of BS 1344, specifying methods of test of other properties of vitreous enamels
9、, are in preparation. The standard at present includes the following Parts. Part 1: Determination of resistance to thermal shock of coatings on articles other than cooking utensils; Part 2: Resistance to citric acid at room temperature; Part 3: Determination of resistance to sulphuric acid at room t
10、emperature; Part 4: Resistance to abrasion; Part 5: Determination of resistance to hot detergent solutions used for washing textiles; Part 6: Resistance to alkali; Part 7: Determination of resistance to heat; Part 8: Determination of resistance to boiling citric acid; Part 9: Determination of resist
11、ance to boiling water and water vapour; Part 10: Determination of resistance to condensing hydrochloric acid vapour; Part 11: High voltage test for articles for use under highly corrosive conditions; Part 12: Production of specimens for testing coatings on sheet steel; Part 13: Production of specime
12、n for testing coatings on cast iron; Part 14: Apparatus for testing with acid and neutral liquids and their vapours; Part 15: Apparatus for testing with alkaline liquids; Part 16: Resistance to thermal shock of coatings on cooking utensils; Part 17: Resistance to hot sodium hydroxide solution; Part
13、18: Determination of fluidity behaviour: fusion flow test; Part 19: Apparatus for determination of resistance to hot detergent solutions used for washing textiles; Part 20: Low voltage test for detecting and locating defects. Additional information. This test method is suitable only when testing vit
14、reous enamelled material in flat sheet form (shaped only by rolling). Cross-reference International standard Corresponding British Standard ISO 2746:1973 BS 1344 Methods of testing vitreous enamel finishes Part 11:1975 High voltage test for articles for use under highly corrosive conditions (Identic
15、al)BS1344-21:1993 BSI 07-1999 iii A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary
16、 of pages This document comprises a front cover, an inside front cover, pages i to iv, pages1to4, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cov
17、er.iv blankISO4532:1991(E) BSI 07-1999 1 1 Scope This International Standard specifies a test method for determining the resistance of enamelled articles to impact. The method is used as a factory production control test. NOTE 1The pistol test is not intended to be used for testing the adhesion of t
18、he enamel. 2 Normative reference The following standard contains provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the edition indicated was valid. All standards are subject to revision, and parties to agreements based
19、 on this International Standard are encouraged to investigate the possibility of applying the most recent edition of the standard indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 2746:1973, Vitreous and porcelain enamels Enamelled articles fo
20、r service under highly corrosive conditions High voltage test. 3 Principle Shooting of a ball-tipped striking bolt of an apparatus operated by adjustable spring tension, against the surface of the test specimen. Evaluation of the point of impact. The load applied to the striking bolt which with one
21、blow produces visible damage to the enamel, is inversely proportional to the sensitivity of the enamelled article to impact. 4 Apparatus The test apparatus (see Figure 1) consists of a striking bolt with a 5 mm steel ball tip which is shot once against the surface under test by means of a pressure s
22、pring (100 mm long, unloaded). The spring load can be continuously adjusted from0to90 N by the power-adjusting sleeve. NOTE 2The newton-metre scale provided on the outside of the apparatus shall only be used as a guide because a non-linear scale can lead to significant errors. The pressure spring is
23、 loaded by means of a clamp. The spring constant is 20 N/cm 0,5 N/cm. When the spring is loaded, it is kept stationary by a holder on the striking bolt and released by the trigger for striking. For testing, a tripod can be fixed at the front of the apparatus in order to keep the apparatus vertical a
24、gainst the test surface. The front of the tool is convex-shaped for testing concave articles. For testing articles with small radii, it is supplied with a cross-groove. In the range of application of the apparatus, the error in reading shall not be greater than 3 %. See Annex A for the calibration a
25、nd determination of the zero point of the apparatus. 5 Test specimens The enamelled articles are the test specimens. The sampling of the test specimens and their number shall be agreed upon between the supplier and the customer. If no agreement had been made, test at least two test specimens. Figure
26、 1 Test apparatus (The pressure spring is shown loaded)ISO4532:1991(E) 2 BSI 07-1999 6 Procedure The test specimens shall be tested in conditions identical to those used in practice. For testing, the apparatus may be fixed in a strong support and the test specimens fixed with the surfaces to be test
27、ed against the front of the apparatus. Carry out the pistol test at various places with increasing loads. In a preliminary test, starting with a load of 10 N and increasing by 10 N each time, establish the integer of 10 N at which the enamel is not visibly damaged. From this value onwards, increase
28、the spring load by 2 N each time until the first visible damage is noticed (see clause 7). The distance between two points of impact, or the distance between a point of impact and a sign of damage on the enamel, shall be at least 20 mm. The parts of the enamelled articles which shall be submitted to
29、 the pistol tests and their conditions of support shall be agreed upon for each case. Carry out at least five pistol tests. 7 Expression of results After each pistol test, observe the point of impact from a distance of 250 mm by normal sight and note the type of damage. The final valuation shall be
30、made after 24 h. The first visible sign of damage of enamel at the point of impact shall be used as a criterion of the impact sensitivity of the enamelled article, for example cracking, powdering off, spalling and chipping. The mark of the striking bolt shall not be considered as sign of damage. Aft
31、er the pistol test, it is permitted to rub the test specimen with an alcoholic dye solution, an ink or a similar colouring solution, to make the damage more easily visible. In addition, it can be advantageous to use the high-voltage test (according to ISO 2746) for certain articles, especially those
32、 used under highly corrosive conditions. NOTE 3Test results can only be compared if a) the test specimens are similar, especially considering the thickness of the basis metal and of the enamel coat; b) the same kind of support was used; c) the pistol tests were applied to similar points on the test
33、specimens. 8 Test report The test report shall include the following information: a) a reference to this International Standard; b) a description of the articles tested (especially their dimensions and mass, and if possible a sketch; or also the thickness of the basis metal and of the enamel coat);
34、c) the number of specimens tested; d) the type of support used; e) the position of the points of impact on the article (for example in the case of pots: rim, bottom, inside or outside); f) the number of pistol tests per test specimen; g) the spring load used, in newtons, rounded to the nearest 2 N,
35、necessary to damage the enamel; h) the appearance of the damaged places, if necessary with photographs; i) whether the high-voltage test was used and, if so, the voltage applied.ISO4532:1991(E) BSI 07-1999 3 Annex A (informative) Calibration and determination of the zero point of the apparatus A.1 C
36、alibration Clamp the striking bolt with its barrel in a vertical position in a support so that the bolt can be loaded and unloaded. The loading of the striking bolt is effected by dismantling the clamp, thus freeing a hole into which a rod with a length of about 15 cm can be inserted, corresponding
37、to pre-defined striking bolt load. If the apparatus is supplied with a bolt on the back of the apparatus, dismantling is not necessary as the calibration weights can be fixed there. Submit the striking bolt to a load of 10 N. Determine, by reading the scale, the position in which the load is neutral
38、ized by checking that the striking bolt is just unloaded. Repeat this procedure with increasing loads. Plot a graph of the readings adjusted as a function of the weight of the rod against the loads. Read the zero-point deviation from the graph (see examples in A.2). The spring constant is correct wh
39、en the graph makes an angle of 45 with the axes. If this is not the case, the apparatus is not suitably calibrated and a correction shall be made using the graph. A.2 Examples for the determination of the zero point of two different apparatuses The values given in Table A.1 were obtained for two dif
40、ferent apparatuses, when tested according to A.1. Table A.1 Values obtained for two different apparatuses when tested according to A.1 According to Figure A.1, the zero deviation of apparatus No. 1 is 3 N, that of apparatus No. 2 is7N. Values in newtons Load applied Apparatus reading Apparatus No. 1
41、 Apparatus No. 2 10,0 15,0 20,0 50,0 12,5 17,5 23,0 54,0 17,5 23,0 27,5 57,5 Figure A.1 Graph for the determination of the zero point of two different apparatusesISO4532:1991(E) 4 BSI 07-1999 Annex B (informative) Bibliography 1 Fachausschu-Bericht Nr. 4 des Vereins Deutscher Emailfachleute e.V. Prf
42、ung von Email: Schlagversuch. Technical Report No. 4 of the Society of German Enamel Specialists: Testing of enamel Pistol test. Publisher Brunke Garrels, Hamburg, 1958. Available from: Verlag des Vereins Deutscher Emailfachleute e.V., Zehlendorfer Strae 24, D 5800 Hagen 1.BS1344-21:1993 BSI 07-1999
43、 List of references See national foreword.BS 1344-21: 1993 ISO 4532:1991 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on standards in Europe and at the international le
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