1、BRITISH STANDARD BS 6043-4.9: 1991 Methods of sampling and test for Carbonaceous materials used in aluminium manufacture Part 4: Cold ramming pastes Section 4.9 Determination of the cold crushing strength of baked rammed paste NOTEIt is recommended that this Section be read in conjunction with the g
2、eneral information in BS6043-4.0, published separately.BS6043-4.9:1991 This British Standard, having been prepared under the directionof the Chemicals Standards Policy Committee, waspublished under the authorityof the Standards Boardand comes into effect on 30 September 1991 BSI 10-1999 The followin
3、g BSI references relate to the work on this standard: Committee reference CIC/24 Draft for comment 90/54849 DC ISBN 0 580 19934 7 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Chemicals Standards Policy Committee (CIC/-) to Technical C
4、ommittee CIC/24, upon which the following bodies were represented: Aluminium Federation British Ceramic Research Ltd. Chemical Industries Association Institute of Petroleum Refractories Association of Great Britain Amendments issued since publication Amd. No. Date CommentsBS6043-4.9:1991 BSI 10-1999
5、 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Principle 1 3 Apparatus 1 4 Materials 1 5 Sampling 1 6 Preparation of test samples 2 7 Procedure 2 8 Calculation and expression of results 2 9 Test report 2 Figure 1 Typical ancillary adaptor for compression testing m
6、achine 1 Publication(s) referred to Inside back coverBS6043-4.9:1991 ii BSI 10-1999 Foreword This Section of BS6043 has been prepared under the direction of the Chemicals Standards Policy Committee to provide a method of test for cold ramming pastes used in the production of aluminium. There is no c
7、orresponding International Standard; however, it is intended, upon publication of this Section of BS6043, that it be offered to the International Organization for Standardization (ISO) for possible adoption as an International Standard. It is essential to use BS6043-4.1, BS6043-4.6 and BS6043-4.7 in
8、 conjunction with this Section of BS6043. This standard describes a method of test only, and should not be used or quoted as a specification defining the characteristics of a product. Reference to this Section should indicate that the method of test used is in accordance with BS6043-4.9:1991. A Brit
9、ish 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 of pages This document comprises a fron
10、t cover, an inside front cover, pages i and ii, pages1 and2, 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 cover.BS6043-4.9:1991 BSI 10-1999 1 1 Sc
11、ope This Section of BS6043 describes a method for the determination of the cold crushing strength of baked rammed cold ramming pastes used in aluminium manufacture. NOTEThe titles of the publications referred to in this standard are listed on the inside back cover. 2 Principle A baked test piece of
12、known dimensions is produced from a test sample of cold ramming paste by ramming under regulated conditions followed by baking according to a defined programme. The baked test piece is subjected under specified conditions to a steadily increasing compressive load until failure occurs,i.e.when the te
13、st piece cannot support a further increase in load. The crushing strength is calculated from the maximum load indicated at failure and the cross-sectional area over which the load is applied. 3 Apparatus 3.1 Ramming apparatus, and the other apparatus described in clause4 of BS6043-4.7:1991. 3.2 Mech
14、anical or hydraulic compression testing machine, conforming to grade2.0 of BS1610-1, fitted if necessary with an adaptor see item c) andFigure 1. The machine, or ancillary adaptor if fitted, shall have the following features: a) the steel platens shall have a Rockwell hardness value of58.0HRC to62.1
15、HRC (Vickers hardness650HV to750HV, seeBS860); b) the platens shall be ground plane to a flatness tolerance of0.03mm over the area to be in contact with the test piece, and shall have an arithmetical mean deviation of the profile (R a ) not greater than3.2m when determined in accordance with BS1134-
16、1; c) the upper platen shall work on a seating that will compensate for small deviations from parallelism between the platen and the test piece and shall overlap the entire cross-sectional area of the test piece by at least2mm. A testing machine whose upper platen does not comply with the size speci
17、fied in3.2 c) and d) shall be used in conjunction with an ancillary adaptor, such as that shown inFigure 1, placed centrally between the platens of the machine. d) both platens shall have a diameter or side length no greater than110mm; e) the lower platen shall have its centre clearly marked and hav
18、e concentric circles scribed to assist in positioning the test piece so as to achieve coaxial loading. 4 Materials 4.1 Metallurgical or regular-grade petroleum coke, as described in5.1 of BS6043-4.7:1991. 4.2 Plane (non-corrugated) paperboard or strawboard, of thickness between3mm and4mm. 4.3 Refrac
19、tory cement, as described in5.2 of BS6043-4.7:1991. 5 Sampling Prepare a representative laboratory sample of cold ramming paste in accordance with BS6043-4.1. Figure 1 Typical ancillary adaptor for compression testing machineBS6043-4.9:1991 2 BSI 10-1999 6 Preparation of test samples Prepare three g
20、roups of test samples, each comprising at least three test samples, from the laboratory sample (clause5) by the method described in7.1 and7.2 of BS 6043-4.7:1991. 7 Procedure 7.1 Preparation of baked test pieces Prepare three groups, each comprising three rammed test pieces50mm in diameter and502mm
21、in height, from the test samples (seeclause6) by the procedure described in8.1 of BS6043-4.7:1991 using the ramming apparatus(3.1). If the cold ramming paste requires pre-curing before being baked, pre-cure the test pieces in accordance with8.3 of BS6043-4.7:1991. Bake the rammed test pieces by the
22、procedure described in8.4 of BS 6043-4.7:1991. Dry the baked test pieces at110 5 C for2h and allow them to cool to ambient temperature in a desiccator. 7.2 Measurement of parallelism Make four measurements of the height of each baked test piece (see7.1) at the extremities of two perpendicular diamet
23、ers. Correct any discrepancies greater than1.0mm between any two measurements of the height by machining the test piece in accordance with7.4. 7.3 Measurement of perpendicularity Place one perpendicular edge of a set square in contact with a horizontal plane surface and set the other perpendicular e
24、dge vertically. Place the baked test piece (see7.1) on one end face on the plane surface and successively bring the side of the test piece into contact with the vertical edge of the set square at each of the four positions corresponding to the height measurements. Measure the maximum gap between the
25、 set square and the test piece at each location. Correct any discrepancy in perpendicularity greater than1mm by machining the test piece in accordance with7.4. 7.4 Correction of discrepancies in parallelism or perpendicularity Machine any baked test pieces with discrepancies in parallelism (7.2) or
26、perpendicularity (7.3) greater than1mm to bring it within the required tolerance whilst maintaining a height of502mm and a diameter of502mm. Reject any test pieces which cannot be corrected in this way,i.e.by machining, and prepare replacement baked test pieces from fresh test samples (see clause6).
27、 7.5 Measurement of cross-sectional area Measure two perpendicular diameters of each baked test piece at one-third of its height and a further two perpendicular diameters at two-thirds of its height. Measure to the nearest0.1mm and calculate the mean of the four measurements to the nearest0.1mm. Cal
28、culate the cross-sectional area of each of the test pieces in square millimetres. 7.6 Determination Perform the following determination for each of the nine baked test pieces (see7.1). Place the test piece centrally between the platens of the testing machine(3.2), interposing the paperboard or straw
29、board (4.2) between the platens and the loadbearing faces of the test piece. Select a load range on the testing machine (3.2) so that the expected load at failure is within the calibrated range of the machine. Apply the load smoothly and continuously, increasing the stress at a rate of1.0 0.1N/mm 2
30、s until the test piece fails, i.e.until the load value on the compression testing machine ceases to increase. Record the maximum load, in newtons. 8 Calculation and expression of results Calculate the crushing strength C of each of the test pieces, in N/mm 2 , using the following equation: where: Ca
31、lculate the mean crushing strength for each of the three groups of baked test pieces (see7.1) and express the results for each group to three significant figures. 9 Test report The test report shall include the following information: a) a complete identification of the material being tested; b) a re
32、ference to this British Standard, i.e.BS6043-4.9:1991; c) the conditions of preparation (see7.1), whether an ancillary adaptor has been employed (see3.2) and the mean crushing strength of each of the three groups of test pieces, calculated and expressed according to clause8; d) any unusual features
33、noted during the determination; e) any operation not included in this British Standard or regarded as optional. F max is the maximum load recorded at failure(see7.6) (in N); A is the cross-sectional area of the test piece(see7.5) (in mm 2 ). C F max A - =BS6043-4.9:1991 BSI 10-1999 Publication(s) re
34、ferred to BS 860, Tables for comparison of hardness scales. BS 1134, Assessment of surface texture. BS 1134-1, Methods and instrumentation. BS 1610, Materials testing machines and force verification equipment. BS 1610-1, Specification for the grading of the forces applied by materials testing machin
35、es. BS 6043, Methods of sampling and test for carbonaceous materials used in aluminium manufacture. BS 6043-4, Cold ramming pastes. BS 6043-4.0, General introduction 1) . BS 6043-4.1, Methods of sampling. BS 6043-4.6, Maximum rammed apparent density 2) . BS 6043-4.7, Preparation of baked rammed test
36、 pieces and determination of baked apparent density, change in volume and loss in mass. 1) Referred to on the front cover only. 2) Referred to in the foreword only.BS 6043-4.9: 1991 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsib
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