1、BSI BS*1902: SEC%5.3 O1 W 1624669 0301742 b BS I902 : Section 5.3 : 1990 UDC 666.76.017 : 666.9.046 : 666.9.017 : 536.4131 : 620.1 British Standard Methods of testing. R ef r ac t ory rn at er a Is Part 5. Refractory and thermal properties Section 5.3 Determination of thermal expansion (horizontal m
2、ethod to 1 100C) (method 1902-503) Mthodes dessai des matriaux rfractaires Partie 5. Proprits rfractaires et proprits thermiques Section 5.4 Dtermination de la dilatation thermique (mthode horizontale jusqu 1100 O C) (Mthode 1902-503) Prfung feuerfester Werkstoffe Teil 5. Feuerfeste und thermische E
3、igenschaften Abschnitt 5. Bestimmung der Wrrnedehnung bei 1100 O C (Waagerecht-Verfahren; Nr. 1902-503) British Standards Institution _- .- t BSI BS*kL902: SEC*5.3 O3 3624bb9 0303743 8 = BS 1902 : Section 5.3 : 1990 Foreword This Section of BS 1902 : Part 5 has been prepared under the direction of t
4、he Refractory Products Standards Policy Committee. The method given in this Section supersedes those given in BS 1902 : Part IA : Section IO, which will be deleted by amendment. Compliance with a British Standard does not of itself confer immunity from legal obligations. 1 BSI BS*2902: SEC*.5.3 O2 m
5、 lb24669 0302744 T m I BS 1902 : Section 5.3 : 1990 Contents Foreword Committees responsible Method 1 Scope 2 Designation 3 Definition 4 Principle 5 Apparatus 6 Test pieces 7 Calibration 8 Procedure 9 Calculation and expression of results 10 Test report Appendix A Preferred construction of apparatus
6、 Table 1 Thermal expansion reference data for polycrystalline alumina, relative to 20 OC Page inside front cover Back cover Figures 1 Suitable system for automatic recording of 2 Assembly of test piece and measuring device 3 Preferred type of thermal expansion apparatus expansion and temperature 2 2
7、 2 2 2 2 3 4 4 5 6 3 3 4 7 1 iSI BS*1902: SEC*S-3 OL M 1624669 0301745 L m BS 1902 : Section 5.3 : 1990 Method NOTE. This Section is to be read in conjunction with BS 1902 : Section 5.0 Introduction and Section 3.1 Guidance on sampling Section 5.0 shows the general arrangement of BS 1902 and lists t
8、he Sections of Part 5, 1 Scope This Section of BS 1902 : Part 5 describes a method for determining the thermal expansion of refractory materials. It is applicable only to products which have been fired to a temperature equal to or greater than the upper limit of intended testing. The maximum tempera
9、ture for testing is 1100 OC. NOTE 1, The temperature is restricted because of the material recommended for the equipment and the absence of water cooling. NOTE 2. A method for testing at temperatures up to 1500 Oc is given in BS 1902 : Section 5.14. NOTE 3. The tith of the publlcations referred to i
10、n this standard are listed on the inside back cover. 2 Designation The method described in this Section is referred to by the . following designation: Method 1902-503 3 Definition For the purposes of this Section of ES 1902 : Part 5, the following definition applies: 3.1 thermal expansion. The propo
11、rtional extension which occurs when a material is heated. 4 Principle A test piece is heated at a specified, uniform rate and its change in length and temperature measured, either con- tinuously or at regular and frequent intervals during the heating. The thermal expansion, relative to ambient tempe
12、rature, is calculated for the temperature of the test piece and the results either plotted as a graph or expressed as a mean coefficient of expansion for a given temperature range. 5 Apparatus 5.1 General. The apparatus shall consist of a furnace and the three components given in 5.2 to 5.4, shall b
13、e of a size to accommodate the test piece (see 6.21, and shall be capable of being calibrated in accordance with clause 7. The preferred construction of the apparatus shall be as given in appendix A. The use of any other material for the construction shall be reported. _- -_ 5.2 Measuring device, fo
14、r measuring changes in the length of the test piece, which may be one of the following: (i) A dialgauge with jewelbearings, with a minimum range of 5 mm and a scale graduated to 0.002 mm. (i) A digital displacement indicator, with a minimum range of 5 mm, reading to an accuracy of 0.002 mm. (i) A li
15、near transducer, with a minimum range of 5 mm and linearity of 0.1 % or better, with a millivolt- meter of suitable range and linearity of 0.1 % or better. (iv) A linear transducer, for automatic recording, with a minimum range of 5 mm, linearity of 0.1 % or better, and an X-Y recorder which has lin
16、earity and repeat- ability better than 0.1 % of full-scale deflection and variable control of sensitivity on ranges. If a transducer is used (iii) or (iv), its sensitivity (mm/V) shall be checked using a micrometer each time the apparatus is calibrated (see clause 7). 5.3 Instrumentation, for contro
17、lling the furnace and measuring the temperature of the test piece via the thermo- couple (5.41, consisting of one of the following. (a) For a manual recording system, a ramp generator/ controller with PID (proportional, integral, derivative control), with digital temperature display, a range of at l
18、east 1200 OC and an accuracy of temperature measure- ment of f 0.3 % of full scale. (6) For an automatic recording system (see figure 1) a ramp generator/controller as specified in (a) with analogue signal output for connection to the X-Y recorder (item (iv) of 5.2). 5.4 Thermocouple, platinum- 13 %
19、 rhodium/platinum in accordance with BS 4937 : Part 2. The thermocouple is used as part of the furnace temperature control system and also as an indicator of the temperature of the test piece. 5.5 Vernier callipers, in accordance with BS 887. 5.6 Reference material, used to obtain the calibration da
20、ta to correct the measured change in length of a test piece (see clause 7). The correction to be applied is obtained by calibration using a test piece prepared, preferably, from polycrystalline alumina, which should contain at least 993 % alumina and have a minimum density of 3.70 g/cm3 I The therma
21、l expansion reference data are given in table 1. The use of any other reference material shall be reported, together with the reference data used. 2 A BSI BSx1702: SEC*5.3 O1 Zb2Ybb7 030174b 3 W BS 1902 : Section 5.3 : 1990 The end face in contact with the measuring device shall be ground to a radiu
22、s between 5 mm and 20 mm. If a piece of the specified length cannot be obtained, a shorter piece may be used, down to a minimum length of 60 mm, in which case the apparatus shall be calibrated (see clause 7) using a piece of reference material of the same length as the test piece. 7 Calibration 7.1
23、General It is necessary to correct the measured change in length of a test piece for: (a) the effect of differential expansion in the apparatus which acts in opposition to the measured change in length of the test piece; and (b) systematic errors arising from the design of the apparatus and its meth
24、od of use as described in clause 8. 7.2 Produre for calibration Calibration data to be used in tests to correct the measured changes in length of a test piece shall be obtained as Measure the change in length of a test piece of the reference material (5.61, of dimensions given in 6.2, using the proc
25、e- A follows. The test piece be from the test have the following dimensions: and shall Length: 7522mm Cross-sectional area: 10 f 2 mm square or 10 f 2 mm diameter dure described in clause 8. Record the difference, positive or negative, between the measured change and that Displacement transducer r R
26、omp generotorOC/min. I Single pen -X-Y recorder Thermocouple Proportional and I I intearoi controller/ I II - indica6r LAnoogue signo1 proportionoi to temp. Figure 1. Suitable system for automatic recording of expansion and temperature 3 BSI BS*i(1902: SEC*5*3 01 lb24bb9 0303747 5 M BS 1902 : Sectio
27、n 5.3 : 1990 obtained by calculation using the reference data (table 1) at corresponding temperatures, for the full temperature range of calibration. In a test, correct the measured change in length of a test piece by inclusion of the data obtained by calibration at corresponding temperatures. 7.3 F
28、requency of calibration The calibration procedure (7.2) shall be carried out at intervals not exceeding ten test runs, or whenever the apparatus is serviced or parts replaced. Where the apparatus is supplied with more than one furnace, calibration data shall be obtained and identified for each furna
29、ce. . 8 Procedure 8.1 Ensure that the apparatus is positioned for use in an environment where the temperature, at the start of the test, has been stable at 20 8.2 Dry the test piece at 110 f 5 OC to constant mass and cool in a desiccator to ambient temperature. Measure the length of the test piece t
30、o an accuracy of 0.1 mm with the vernier callipers, between the extreme points of contact on the end faces. 8.3 Insert the test piece in the apparatus. Adjust the thermocouple (5.4) so that its junction is positioned to be in contact with the surface of the test piece, at a point midway along the le
31、ngth of the test piece. Adjust the measuring device (5.2) to make contact with the assembly as shown in figure 2 in such a way as to record both expansion and contraction. Record the initial measurement and the temperature. 8.4 Allow the temperature of the test piece to stabilize before the commence
32、ment of a test run, so that subsequent 3 OC for at least 2 h. measured changes in length relate to an initial temperature of 20f 3OC. 8.5 If manual recording is carried out, note the initial reading of the dial gauge and the temperature, and there- after the change in length and temperature of the t
33、est piece at intervals of 2 minutes during heating. If continuous automatic recording is carried out, note the initial temperature, set the X-Y recorder to suitable ranges for recording the change in length (via the transducer) and the temperature of the test piece. Set the pen of the recorder to ze
34、ro length change and adjust its position on the temperature scale to a reading corresponding to the initial temperature. 8.6 Raise the temperature of the test piece at a rate of 5 f 0.2 K/min until the maximum required temperature is reached and then allow to cool naturally to ambient temperature. 8
35、.7 Re-measure the length of the cold test piece as in 8.2 and record any difference between the initial and after test measurements as a permanent change. 9 Calculation and expression of results Calculate the thermal expansion of a test piece in one of the following ways. (a) Correct the recorded ex
36、pansion data, as described in clause 7 and calculate expansion as a percentage of the initial length of the test piece. Present the percentage expansion values against corresponding temperature either as a graph or in tabulated form. (b) Or, calculate a mean expansion coefficient (Y), for a particul
37、ar temperature range as follows: L2 Li (Tz - TI) (Y= Test piece holder Measuring Push-rod / rTest piece (6.2) device (5.2) I Thermocouple (5.41 I I II I T 1 I Heater Bose Figure 2. Assembly of test piece and measuring device (see 8.3) I- - -_ 4 where LI is the corrected change in length (see clause
38、7) of the test piece (in mm) over the temperature range TZ - T1 (in KI; L1 is the initiai length of the test piece (in mm); TI is the lower temperature of the range (in OC); TZ is the upper temperature of the range (in OC). NOTE. Where the material does not exhibit an almost linear expansion curve,
39、it is not appropriate to calculate a mean expansion coefficient. 10 Testreport The test report shall include the following information: (a) the name of the testing establishment; (b) the date of the test; Lb24669 0301748 7 m BS 1902 : Section 5.3 : 1990 (c) a reference to this method of test, .e. de
40、termined in accordance with method 1902-503; (d) a description of the material tested (e.9. manufac- turer, product, type, batch number); (e) any particular apparatus details (e.g. use of different construction materials) (see 5.1); (f) the reference material used to calibrate the apparatus (see 5.6
41、); (g) the initial and final length of the test piece, indicating any permanent linear change (see 8.7); (h) the tabulated and/or graphical representation of the results or the coefficient of thermal expansion in “C - 1 (see clause 9); (i) the temperature range over which the measurements were made
42、(see 8.6). 5 BSI BS*3902: SEC*D O3 m I1624669 0303749 9 m. BS 1902 : Section 5.3 : 1990 I Appendix Appendix A. Preferred construction of apparatus A.l The preferred apparatus for determining thermal expansion is shown in figure 3. It is mounted on a slate base, A.3 The fused silica rod is attached t
43、o an through which the elements of the thermocouple (5.4) pass. The holes are positioned so that the junction of the thermocouple is in direct contact with the test piece mid-way along its length (see figure 2). rod by to which is fitted an Invar plate, by means of four bolts. The supports for the f
44、used silica-Invar rod, the fused silica tube which holds the test piece, and the measuring device are bolted to this Invar plate. The fused silica-Invar rod is described in A.3, the fused silica tube is described in A.2 and the measuring device is described in 5.2. The assembled apparatus also conta
45、ins the components given in 5.2 to 5.4. A.2 The fused silica tube is closed at one end and fixed at the other end to a support, The test piece (6.2) is placed in the tube between the closed end and the fused silica rod. The top of the tube is pierced by two small holes, means of a screwed collar. Th
46、is assembly is supported on two V-grooved wheels which are fitted with bearings so that the assembly can move smoothly along its axis with minimum resistance, The supports for the wheels are adjustable so that the fused silica rod can be positioned to move centrally in the fused silica tube. A4 The
47、tube furnace, shown in figure 3, surrounds the end of the silica tube and rod, and is designed to give a heating zone corresponding to the position of the test piece. The furnace is fitted with grooved wheels and mounted on rails in order to position it over the tube. It is controlled by a ramp gene
48、rator and proportional controller (see 5.3 and figure i). 6 BSI BS*3902: SEC*5.3 O3 W Lb24bb9 0303750 5 BS 1902 : Section 5.3 : 1990 7 Publications referred to BS 887 BS 1902 Specification for precision vernier callipers Methods of testing refractory materials Section 3.1 Guidance on sampling Sectio
49、n 5.0 Introduction International thermocouple reference tables Part 2 Platinum - 13 % rhodiumlplatinum thermocouples. Type R Methods for sampling and acceptance testing of shaped refractory products Guide to the use of BC 6065 Methods for sampling and acceptance testing of shaped refractory products BC 4937 BS 6065 BS 6434 This British Standard, having been prepered under the direction of the Refractory Products Standards Policy Committee, was published under the authority of the Board of BSI and comes into effect on 31 May 1990 O Bri
