This standard specifies the determination method of the microstructure number of common abrasive tools with ceramic, resin and magnesia binders. This standard is applicable to common abrasive tools with ceramic, resin and magnesia binders. JB/T 8339-1996 Determination method of microstructure number of common abrasive tools JB/T8339-1996 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
Ordinary Abrasives
Determination Method of Organization Number
Subject Content and Scope of Application
JB/T 8339—96
This standard specifies the determination method of organization number of ordinary abrasives with ceramic, resin and magnesia bonds. This standard applies to ordinary abrasives with ceramic, resin and magnesia bonds. 2 Reference Standards
GB 2484
Abrasive Code
GB3604 Determination Method of Density of Ordinary Abrasive Grains GB11269 Determination Method of Total Porosity and Water Absorption of Abrasive Body Volume Density 3 Terminology
3.1 Abrasive Organization Number
Abrasive organization numbers are divided according to different abrasive grain ratios. 3.2 Abrasive Grain Ratio
The volume percentage of abrasive grains in the abrasive. 4 Relationship between the abrasive tool structure number and the abrasive rate
4.1 The relationship between the structure number and the abrasive rate of ordinary abrasive tools with ceramic and resin bonds is shown in formula (1): V=2(31-N).
Where: V. — abrasive rate, %, the tolerance is ±1.5%; structure number (from 0 to 14 or greater)
2 The relationship between the structure number and the abrasive rate of magnesia abrasive tools shall be as specified in Table 1. Table 1
Structure number
Abrasive rate, %
5 Determination of abrasive rate
5.1 Determination of bulk density D
5.1.1 The bulk density D of ceramic and resin bond samples shall be determined according to the method specified in GB11269, and distilled water shall be used as the impregnation liquid. 5.1.2 The bulk density D of magnesia bond samples shall be determined according to the method specified in GB11269, and kerosene shall be used as the impregnation liquid. 5.2 The density of abrasive particles α shall be determined according to the method specified in GB3604. 5.3 Determination of abrasive mass percentage
5.3.1 Vitrified bonded abrasive tools
5.3.1.1 Preparation of samples
Approved by the Ministry of Machinery Industry of the People's Republic of China on April 11, 1996 494
Implementation on October 1, 1996
JB/T8339-96
Preparation of samples Small pieces of 2 to 3 mm in size shall be reduced to about 40 g by quartering. Samples with a particle size finer than 240* shall be further crushed in a manganese steel mortar until all of them pass through a 100* sieve. After removing iron filings with a magnet, they shall be placed in a sample bag and dried at 105110°C for 1 hour. Take them out and place them in a desiccator to cool to room temperature.
5.3.1.2 Apparatus, reagents
Platinum blood, www.bzxz.net
hydrofluoric acid: 40% concentration;
nitric acid: density 1.42,
sulfuric acid: 5+95;
hydrochloric acid: 5+95.
5.3.1.3 Procedure
Weigh 5~10g of the sample and put it into a platinum dish, moisten it with a small amount of distilled water, add 15mL of 40% hydrofluoric acid and 2mL of nitric acid, place it on a sand bath or a low-temperature electric heating plate to heat and decompose, and evaporate to dryness. During the hydrofluoric acid treatment, use a platinum wire to gently press the sample to disperse it, remove it, and then add hydrofluoric acid and nitric acid to treat it. Repeat the operation until the small pieces of sample are completely dispersed. Wash the outer wall of the platinum blood with distilled water, put it into a 400mL beaker containing 100mL of hot sulfuric acid (5+95), and heat it on a sand bath to extract it. After the sample is completely free of platinum blood, wash the platinum with water and take it out. Continue to boil for 15 to 20 minutes, remove it, cool it slightly, and filter it. Wash the filter paper and abrasive with hot hydrochloric acid (5 + 95) 58 times, wash it with hot water 5 times, discard the filtrate, move the filter paper and abrasive into porcelain that has been burned to a constant mass of m2, ash it at low temperature, and then put it in a high-temperature furnace at 750℃ and burn it for 30 minutes. Take it out and put it in a dryer, cool it to room temperature, and weigh it as m1.
5.3.1.4 Results
Calculate the abrasive mass percentage according to formula (2):
A=ml=m2×100%.
Where: A-
abrasive mass percentage;
mass of abrasive crucible, name;
mass of crucible, g;
mass of abrasive sample, 8.
5.3.2 Resin-bonded abrasives
5.3.2.1 Preparation of specimens
Prepare small pieces of specimens with a size of 3 to 5 mm, and cut them into pieces with a quartering method to about 40 g, put them into a specimen bag, dry them at 105 to 110°C for 1 hour, take them out and put them into a desiccator to cool to room temperature.
5.3.2.2 Instruments and reagents
Hydrochloric acid: 10+90, 5+95.
5.3.2.3 Procedure
Weigh about 10 g of the specimen, put it into a porcelain dish (or porcelain dryer), place it on a low-temperature electric furnace, and completely carbonize the specimen without ignition, then move it into a high-temperature furnace at 750°C and burn it until it reaches a constant weight. Take it out, cool it to room temperature, transfer the residue to a 250mL beaker, add 50mL of hydrochloric acid (10+90), boil it slightly for 15 minutes, take it out, cool it slightly, and filter it. Wash it with hot hydrochloric acid (5+95) for 5 to 8 times, and wash it with hot water for 3 to 5 times. Discard the filtrate, transfer the abrasive and filter paper to a porcelain crucible that has been burned to a constant mass of m2, ash it at low temperature, and then put it in a high-temperature furnace at 750℃ and burn it for 30 minutes. Take it out, put it in a dryer and cool it to room temperature, and weigh it as m1. 5.3.2.4 Results
Calculate the mass percentage of the abrasive according to formula (2).
5.3.3 Magnesium abrasives
5.3.3.1 Preparation of samples
Prepare small pieces of the sample with a size of 3 to 5 mm, and reduce them to about 40g by quartering method for use. 5.3.3.2 Instruments and reagents: a. Hydrofluoric acid: 40% concentration; b. Hydrochloric acid: 5+95, 1+1; c. Platinum blood.
5.3.3.3 Procedure
JB/T8339—96
Weigh about 5 g of the sample into a 250 mL beaker, add 100 mL of hydrochloric acid (1+1), heat on a bright wire electric furnace to dissolve the lumps, boil for about 15 minutes, remove, cool, filter with medium-speed filter paper, wash the insoluble matter with hot hydrochloric acid (5+95) 58 times, and then wash with hot water 5 times, transfer the insoluble matter into platinum blood, first incinerate at low temperature, then burn at 700℃ for 20 minutes, remove, cool, add 15 mL of hydrofluoric acid (40%), evaporate to dryness, add 15 mL of hydrochloric acid (5+95), heat on a sand bath for 10 minutes, filter, wash with hot hydrochloric acid (5+95) 5 times, wash with hot water 3 times, and discard the filtrate. The abrasive and filter paper are transferred to porcelain that has been burned to a constant mass of m2, incinerated at low temperature, and then placed in a high-temperature furnace at 700℃ and burned to a constant mass. Weigh mt.
5.3.3.4 Results
Calculate the mass percentage of the abrasive according to formula (2).
5.4 The abrasive rate is calculated according to formula (3):
Where: V—abrasive rate, %;
A—abrasive mass percentage, %;
D——volume density of the sample, g/cm;
0—abrasive particle density, g/cm\.
Additional remarks:
This standard is proposed by the National Technical Committee for Standardization of Abrasives and Grinding Tools. D
This standard is under the jurisdiction of the Zhengzhou Abrasives and Grinding Research Institute of the Ministry of Machinery Industry. This standard is drafted by the Zhengzhou Abrasives and Grinding Research Institute. The drafters of this standard are Ma Jinfeng, Chen Wenping and Ge Zhenhai. 496
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