1、BRITISH STANDARDBS EN 993-11:2007Methods of test for dense shaped refractory products Part 11: Determination of resistance to thermal shockThe European Standard EN 993-11:2007 has the status of a British StandardICS 81.080g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g
2、44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 993-11:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 January 2008 BSI 2008ISBN 978 0 580 58844 0National
3、forewordThis British Standard is the UK implementation of EN 993-11:2007. It supersedes DD CEN/TS 993-11:2003 which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee RPI/1, Refractory products and materials.A list of organizations represented on this committee
4、 can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.Amendments/corrigenda issued since
5、publicationDate CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 993-11December 2007ICS 81.080 Supersedes CEN/TS 993-11:2003 English VersionMethods of test for dense shaped refractory products - Part 11:Determination of resistance to thermal shockProduits rfractaires faonns denses - Partie
6、11:Dtermination de la rsistance au choc thermiquePrfverfahen fr dichte geformte feuerfeste Erzeugnisse -Teil 11: Bestimmung der TemperaturwechselbestndigkeitThis European Standard was approved by CEN on 15 November 2007.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which
7、stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standar
8、d exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standard
9、s bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
10、EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2007 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 993-11:2007: EEN 993-11:200
11、7 (E) 2 Contents Page Foreword3 Introduction .5 1 Scope 6 2 Normative references 6 3 Terms and definitions .6 4 Principle6 4.1 Method A.6 4.2 Method B.6 5 Apparatus .7 6 Test pieces .7 6.1 Number of test pieces .7 6.2 Preparation of test pieces.7 7 Procedure .8 7.1 Heating8 7.2 Cooling8 7.3 Measurem
12、ent8 8 Expression of results 9 8.1 Method A.9 8.2 Method B.9 9 Test report 9 Bibliography 11 EN 993-11:2007 (E) 3 Foreword This document (EN 993-11:2007) has been prepared by Technical Committee CEN/TC 187 “Refractory products and materials”, the secretariat of which is held by BSI. This European St
13、andard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by June 2008, and conflicting national standards shall be withdrawn at the latest by June 2008. This document supersedes CEN/TS 993-11:2003. EN 993 Methods of test for
14、 dense shaped refractory products consists of 20 Parts: Part 1: Determination of bulk density, apparent porosity and true porosity Part 2: Determination of true density Part 3: Test methods for carbon-containing refractories Part 4: Determination of permeability to gases Part 5: Determination of col
15、d crushing strength Part 6: Determination of modulus of rupture at ambient temperature Part 7: Determination of modulus of rupture at elevated temperatures Part 8: Determination of refractoriness-under-load Part 9: Determination of creep in compression Part 10: Determination of permanent change in d
16、imensions on heating Part 11: Determination of resistance to thermal shock Part 12: Determination of pyrometric cone equivalent (refractoriness) Part 13: Specification for pyrometric reference cones for laboratory use Part 14: Determination of thermal conductivity by the hot-wire (cross-array) metho
17、d Part 15: Determination of thermal conductivity by the hot-wire (parallel) method Part 16: Determination of resistance to sulfuric acid Part 17: Determination of bulk density of granular materials by the mercury method with vacuum Part 18: Determination of bulk density of granular materials by the
18、water method with vacuum Part 19: Determination of thermal expansion by a differential method Part 20: Determination of resistance to abrasion at ambient temperature EN 993-11:2007 (E) 4 According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countrie
19、s are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
20、Sweden, Switzerland and the United Kingdom. EN 993-11:2007 (E) 5 Introduction Thermal shock of refractory materials used in furnaces is influenced by three main factors: brick dimensions; heating/cooling conditions; material properties. Thermal shock tests are usually intended to test material prope
21、rties. This is done by standardizing brick dimensions and heating conditions through which a relative order of the quality of different types of bricks can be established. However, in case of thermal shock, this can lead to complications in the field of engineering. The major complication is that, d
22、epending on the type of heating conditions, various material properties are involved. This can be best illustrated on the basis of thermal stress parameters, which are a measure for critical crack initiation. Table 1 Type of heating condition Hot face condition Stress parameter Example sudden temper
23、ature jump / filling of metallurgical vessels constant heat flow into brick . / Furnace preheating constant heating rate /(. cp) . / Controlled preheating where maximum allowable deformation; coefficient of expansion; thermal conductivity; bulk density; cpspecific heat. EN 993-11:2007 (E) 6 1 Scope
24、This European Standard describes two alternative methods for determining the resistance to thermal shock of dense shaped refractory materials by an air quenching method, which proved to give the most reliable results when compared with the behaviour of refractories in furnace linings. Method B can a
25、lso be applied to unshaped refractory materials. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including an
26、y amendments) applies. EN 993-6, Methods of test for dense shaped refractory products - Part 6: Determination of modulus of rupture at ambient temperature 3 Terms and definitions For the purposes of this European Standard, the following terms and definitions apply. 3.1 thermal-shock resistance resis
27、tance of refractory shapes to damage caused by sudden temperature changes between 950 C and room temperature caused by air blowing 3.2 measure of thermal-shock resistance for method A the number of quench cycles withstood under the test conditions, and for method B the residual cold modulus of ruptu
28、re (MOR) and residual sonic velocity after 5 quench cycles under the conditions of the test 4 Principle 4.1 Method A The test piece is homogeneously heated to 950 C in an electric furnace then removed, placed on a steel plate and exposed to blowing air. After quenching, the test piece is subjected t
29、o a stress of 0,3 MPa in a bending machine. This cycle is repeated until failure of the test piece occurs. The resistance to thermal shock is defined by the number of cycles withstood by the test piece before breaking. 4.2 Method B The test piece is homogeneously heated to 950 C in an electric furna
30、ce then removed, placed on a steel plate and exposed to blowing air. After quenching this is repeated 4 times. After cooling down, the residual cold MOR and the residual sonic velocity are determined. The resistance to thermal shock is defined by the percentage residual MOR and residual sonic veloci
31、ty related to the MOR and sonic velocity of non-quenched test pieces. EN 993-11:2007 (E) 7 NOTE Sonic resonance frequency can also be measured but can give different results. For both method A and method B, other quenching temperatures may be agreed upon by the parties concerned and shall be noted i
32、n the test report. 5 Apparatus 5.1 Electrically heated furnace, capable of maintaining a temperature of 950 C 25 C. 5.2 Thermocouple, for use at temperatures in excess of 1 000 C. 5.3 Drying oven. 5.4 Heating cabinet, for preheating at 250 C to 300 C. 5.5 Blowing device, with a 8 mm diameter nozzle
33、of 5 mm length. 5.6 Equipment for measuring the cold MOR in accordance with EN 993-6. 5.7 Steel plate, 400 mm x 250 mm x 20 mm, with pins to locate the test piece under the air-blast; depending on the dimensions of the test-piece, the pins are located in such a manner that the air jet blows at the i
34、ntersection of the diagonals of the test-piece on cooling. 5.8 Equipment for measuring the sonic velocity NOTE Equipment for measuring the sonic velocity in refractories is commercially available and should be used in accordance with the manufacturers instructions. 5.9 Insulated iron tongs for handl
35、ing the test piece after heating 6 Test pieces 6.1 Number of test pieces 6.1.1 Method A Unless a different number of test pieces has been agreed upon, one test piece shall be taken from each item. 6.1.2 Method B Unless a different number of test pieces has been agreed upon, four test pieces shall be
36、 used. Two test pieces are used for the determination of the cold MOR before testing, MORn. The other two test pieces are used for the thermal shock test. For all four test pieces, determine the sonic velocity, SVn, axially in length of the test pieces before testing. 6.2 Preparation of test pieces
37、6.2.1 Shape For method A the test pieces shall have the dimensions of a quarter-standard brick, i.e. 114 mm x 64 mm x 64 mm. For method B the test pieces shall have the dimensions of a half-standard brick, i.e. 230 mm x 64 mm x 54 mm. EN 993-11:2007 (E) 8 They shall be sawn or ground from bricks. NO
38、TE The use of other shapes may be agreed by the parties, but the results will not be directly comparable with those obtained using the test pieces stated above. The test pieces shall be prepared with care so that the brick texture is not damaged. The location within the bricks from which the test pi
39、eces are to be taken shall be agreed upon. 6.2.2 Drying of the test pieces Dry the test pieces at 110 C 5 C to constant mass. Constant mass is obtained when the change in mass after two successive periods of 1 h drying, is not more than 0,1 %. Protect the test pieces from moisture before testing. 7
40、Procedure 7.1 Heating 7.1.1 Place the test pieces on one of their long faces, i.e. for method B on a 230 mm x 64 mm face, into a heating cabinet pre-heated to 250 C and 300 C and keep them at this temperature for at least 4 h. 7.1.2 Put the test pieces into the furnace at 950 C 25 C. The temperature
41、 of the furnace is measured with a thermocouple positioned over the centre of the basal area of the furnace approximately 20 mm above the test pieces. Immediately after the door of the furnace has been closed, the temperature should not be less than 750 C. Keep the samples in the furnace until they
42、are evenly heated. 7.2 Cooling Remove a test piece as quickly as possible from the furnace using insulated iron tongs and place its long face on the steel plate, taking care that the nozzle of the air-blowing device and the centre of the upper face are aligned, with the help of the locating pins. Th
43、e distance between the nozzle and the test piece shall be 100 mm. Blow compressed air on the test piece for five minutes, ensuring that the pressure immediately before the nozzle is constant and equal to 0,1 MPa 0,01 MPa. Be sure that the compressed air is at room temperature and does not contain mo
44、isture likely to concentrate in droplets. Always expose the same face of the test piece to the blast. NOTE If conditions remain in accordance with 7.1 and 7.2, more than one test-piece can be simultaneously or successively tested. Should it be necessary to interrupt the test, the test pieces shall b
45、e maintained in the heating cabinet at 250 C to 300 C after the last quenching. When testing is resumed, the test pieces shall be placed immediately in the furnace at 950 C 25 C. 7.3 Measurement 7.3.1 Method A 7.3.1.1 After quenching, the test piece is submitted to a bending strength of 0,3 MPa 0,05
46、 MPa gradually and without shock. 7.3.1.2 The distance between supports shall be 100 mm. The thrust column and the supports shall have a radius of 5 mm. NOTE If the test piece breaks, the test is completed. EN 993-11:2007 (E) 9 7.3.1.3 If the test piece withstands the bending stress, place it again
47、into the furnace at 950 C and start the same cycle. Continue the test until the test piece breaks in the bending test or breaks up into two or more pieces under the cooling blast. The test shall be ended when the test piece has withstood 30 quenchings. 7.3.2 Method B 7.3.2.1 General After 5 quenchin
48、gs, the following measurements and determinations have to be applied: 7.3.2.2 After cooling down to ambient temperature, again measure the sonic velocity, SVquenched. NOTE It can be interesting to study the behaviour of the sonic velocity in function of cycles. In this case the test pieces are coole
49、d down to ambient temperatures after each cycle before the measurements. 7.3.2.3 The determination of the cold MOR, MORquenched, has to be made so that the blown face is now the bottom face during the test. 8 Expression of results 8.1 Method A Express the resistance to thermal shock of the product as the number of quenching cycles withstood by the test piece before failure. 8.2 Method B Express the resistance to thermal shock of the product as the % residual MOR, MORresidual, and % residual Sonic Velocity,
