JB/T 7987-1999 JB/T 7987-1999 Ordinary abrasive microcrystalline corundum JB/T7987-1999 Standard download decompression password: www.bzxz.net

JB/T 79871999
This standard is a revision of JB/T7987-95 (formerly GB5997-86) (Technical conditions for microcrystalline corundum).
This standard is consistent with the technical content of JB/T7987-95, only the relevant provisions have been revised. Appendix A of this standard is the supplementary record of the standard.
This standard replaces JB/T7987-95 from the date of implementation. This standard is issued by the National Technical Committee for Standardization of Building Materials The standard was proposed and coordinated by the committee. The drafting unit of this standard is Sisha Co., Ltd. The main drafters of this standard are Luo Shucai and Zhang Juelin. 195
Mechanical Industry Standard of the People's Republic of China
Ordinary Abrasives
Microcrystalline Corundum
This standard specifies the technical requirements, test methods, inspection rules and packaging of microcrystalline corundum materials. This standard is not applicable to the crystal corundum materials used in the manufacture of table tools and grinding materials, etc. 2 Reference Standards
JB/T 7987—1999
Daishan JB/T 7987-95
The clauses included in the following standards constitute the clauses of this standard through reference in this standard. When this standard is issued, the version shown is effective. All standards will be revised. The parties using this standard should explore the possibility of using the latest version of the following standards: GB/T2481.1-1998
Testing and marking of particle size composition of whole materials for consolidation tools Part 1 Grinding F4--F220GB/T 30431989
GB/T 4676—1984
JB/T 65691993
JB/T 6570—1993
Chemical analysis method
Palm brush jade
Ordinary grinding sampling method
Powder material packaging
Determination method of trace matter content
Sand material
JB/T 7984.3—1995
Technical requirements
Ordinary material
The chemical composition should comply with the provisions of Table 1.
Solid material size
F4--F50
F100~F220
Determination method of particle density
Chemical maximum
94.00 96.50
93. 00~ 96. 00
2. 20~8. 80
3.2 Crystal size: The number of crystals less than or equal to 300 μm shall not be less than 80%, and the size of large crystals shall not be shorter than 600 μm. 3.3 Light density, F46 (representative number) shall not be less than 3.90 g/cm. 3.4 Particle size composition: It shall comply with the provisions of GB/T2481.1. 3.5 Iron alloy grain content: F30 and coarse numbers that do not pass the 355 μm sieve are zero; F36 to F90 numbers that do not pass the 355 μm sieve are zero. When passing the particle size inspection, the iron alloy particles of the lowest sieve number are zero; when F100 and the following group numbers fail to pass the particle size inspection, the iron alloy particles of the mixed test lower sieve are zero,
3.6 The content of magnetic substances; the content of magnetic substances of F24 to F220 is not more than 0.30%, 4 Test method
Chemical composition is tested in accordance with the provisions of GB/T3043, 4.1
Product size is tested in accordance with Appendix A (Appendix of the standard). 4.2
Pre-granule density is tested in accordance with the provisions of JB/T7984.3, 4.3wwW.bzxz.Net
National Machinery Industry Bureau approved 196
2000-01-01 chain
JB/T7987-1999
Mild group or test in accordance with the provisions of GB/T2481.1. 4.4
The content of ferroalloy particles and functional materials shall be inspected in accordance with the provisions of JB/T6570. 4.5
Inspection rules
The extraction and reduction of samples shall be carried out in accordance with the provisions of GB/T4676. 5.1
Each batch of products shall be inspected in accordance with the technical requirements. When all the inspected items meet the technical requirements, the batch of products shall be qualified. 6
According to the provisions of JB/T6569.
A1 Equipment and Instruments
A1.1 Film Sensor
A1.2 Metallographic Display Feedback
The magnification and scale values ​​are shown in Table A1.
Daily × material capsule (times)
A2 Selection and mounting of sample blocks
Selection of sample blocks
JB/T 79871999
Appendix A
(Standardized microbiological records)
Method for determining the crystal size of microcrystals
Using the micrometer to the value (m/grid)
Select no less than four representative parts on the sample to be tested, and use a gold-yin stone grinding wheel to prepare sample blocks with a cross-sectional area of ​​about 1.5cm2 in two directions perpendicular and parallel to the growth of the sample body, and number the sample blocks respectively. A2.2 Mounting of sample blocks
Place the cut sample blocks in a plastic tube with a height of about 17mm and an inner diameter of about 18mm. Then inject molten sulfur into the tube, and after cooling, it becomes a grinding sample block.
A3 Reflective Film Preparation
A3.1 Coarse and fine
Prepare the colored silicon carbide of F240 and F360 with water (1:4) to prepare the bottom suspension. In the order of first coarse and then fine, spray the suspension evenly on the center of the coarse grinding disc (cast iron disc) with a hairspray. Roughen the sample and wash it with water. Then check the sample with a ruler. The surface should be flat and without pits.
Prepare the carburized dew of F800 and F1200 with water (1:5) to prepare the lubricating liquid. In the order of first coarse and then fine, the sample should be fine-grained on the fine-grained disc (iron disc with glass plate). The surface of the fine-grinded sample should have the ability to reflect light. The nearby objects are reflected on the surface and the image is clear. A3.3 Polishing
Mix 1mm white jade powder with water (1:5) to make a base suspension, and evenly sprinkle it on the center of the tracing disc (a layer of felt on the iron disc), polish the grinding disc sample for 3~5min, wash it with clean water, blow it dry with hot air, or reflective film, and store it in a dryer for later use. A4 Determination of crystal size
A4.1 The size of the product is expressed by the inspection value of the product. The connecting line of two points on the product is squared and the longest short auxiliary dimension perpendicular to the long axis is the width.
A4.2 Place the prepared reflective film on the metallographic imaging stage, and observe the appearance with a low-power (5×8) lens. Select the test point. A4.3 Use a medium-power (10X8) lens to observe and determine the maximum, average and minimum values ​​of the crystal size. A4.4 Use the straight line method to select each area for testing, record the size of each sample through the eyepiece micrometer, 198
JB/T 7987-1999
The number of samples tested is not less than 5G, and the crystal size is expressed as; the measured sample size is divided into sections as required, and the average value is calculated respectively. A4.7 The percentage content of crystals of different sizes is calculated according to formula (A1): va=
Where: VA—the percentage content of crystals of a certain size; N.-the number of samples in a certain size range
The total number of samples tested.
#×100%
..(Al)
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