This standard specifies the method summary, equipment and materials, specimens, viscosity agent calibration, test steps, result calculation and test deviation, and test report for the viscosity test of continuous casting mold slag. This standard is applicable to the test of the viscosity of continuous casting mold slag, and the test range is: viscosity value ≥ 0.1Pa·s. YB/T 185-2001 Test method for viscosity of continuous casting mold slag YB/T185-2001 Standard download decompression password: www.bzxz.net

The People's Republic of China Ferrous Metallurgy Industry Standard YB/T 185--2001
Test method for viscosity of continuous casting mold powder
Method of the test for viscosity of continuous casting mold powder2001-07-09 Issued
National Economic and Trade Commission Issued
2002-01-01 Implementation
YB/T185-2001
The physical test method for continuous casting mold powder consists of the following standards: YB/T185 Test method for viscosity of continuous casting mold powder; YB/T186 Test method for melting temperature of continuous casting mold powder; YB/T187 Test method for bulk density of continuous casting mold powder; YB/T188 Test method for particle size distribution of continuous casting mold powder; YB/T189 Test method for moisture content (110℃) of continuous casting mold powder. This standard uses the rotation method to test the viscosity value of continuous casting mold powder slag at 1300℃. This standard is proposed and managed by the Metallurgical Industry Information Standards Research Institute. The responsible drafting units of this standard are Chongqing University and Tianjin Steel Pipe Company. The participating drafting units of this standard are: Central Iron and Steel Research Institute, Baoshan Iron and Steel Group Corporation, Wuhan Iron and Steel Group Corporation, Baotou Iron and Steel Company, Beijing University of Science and Technology, Shanghai Shengqiao Metallurgical Materials Factory. The main drafters of this standard are: Wang Qian, Wang Yu, Chi Jinghao, Fu Jicheng, Zeng Zhaohui. Standard of the People's Republic of China for the test method for viscosity of continuous casting mold powder
Method of the test for viscosity of continuous casting mold powder1 Scope
YB/T185-2001
This standard specifies the method summary, equipment and materials, specimens, viscometer calibration, test steps, result calculation and test deviation, and test report for the test of viscosity of continuous casting mold powder.
This standard is applicable to the test of viscosity of continuous casting mold powder, and the test range is: viscosity value ≥ 0.1Pa·s. 2 Referenced standards
The clauses contained in the following standards constitute the clauses of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T8170-1987 Rules for numerical rounding
YB/T5218-1993 Steel wire for musical instruments
3 Summary of methods
Under conditions higher than the melting temperature of continuous casting protective slag, a graphite or metal molybdenum cylinder is immersed in the protective slag melt contained in a graphite crucible, and the slag viscosity is determined by testing the torque of the cylinder. When the geometric conditions of the cylinder and graphite, the size of the hanging wire and the speed are fixed, the viscosity is only proportional to the torsion angle or torque of the hanging wire, that is, the time difference t of the pulse signal, and there is
n=K·At
Where: K is an instrument constant. When the measuring system (measuring rod, hanging wire, rotation speed) is fixed, it can be calibrated by a standard viscosity liquid of known viscosity, and the viscosity n of the continuous casting protective slag can be calculated by measuring △t. 4 Equipment and Materials
Schematic diagram of the rotational viscometer (see Figure 1), the main equipment includes: electric heating furnace, temperature measuring device, graphite crucible, probe and its drive device, torque or viscosity detection device.
4.1 Electric heating furnace: The electric heating furnace is a vertical tubular furnace and should have temperature regulation and control functions. The difference between the length of the constant temperature zone of the furnace tube and the melt depth is not less than 20mm. At 1300℃, the temperature fluctuation in the constant temperature zone is not more than 3℃; the operating temperature of the heating furnace is not lower than 1400C, and the furnace tube is atmospheric atmosphere or protective atmosphere.
4.2 Temperature measuring device: The temperature measuring device consists of a B-type or S-type thermocouple and a temperature display and recording instrument. The thermocouple meets the industrial heavy-grade accuracy requirements; the thermocouple with a protective tube is in contact with the center of the bottom of the graphite. The absolute value of the difference between the thermocouple test temperature and the temperature in the slag is ≤10℃, and correction is performed.
Approved by the State Economic and Trade Commission on July 9, 2001 and implemented on January 1, 2002
YB/T185—2001
1- Rotational viscometer: 2- Continuous casting protection slag; 3- Probe; 4- Graphite crucible; 5- Thermocouple; 6- Heating furnace shell Figure 1 Schematic diagram of rotational viscometer
4.3 Graphite crucible, hanging wire and probe: The crucible is made of electrode graphite or high-purity graphite, and the probe is made of high-purity graphite or metal molybdenum. The probe is a cylinder with a diameter of not less than 10mm. The probe is connected to the metal aluminum rod, and the metal molybdenum rod is connected to the motor through the hanging wire and connecting device. The hanging wire should comply with the provisions of YB/T5218. The hanging wire is made of T8MnA and has a diameter of 0.10mm~0.20mm. The probe speed is ≤20r/min, the distance between the upper edge of the probe and the slag surface is 10mm~12mm, the distance between the lower edge of the probe and the bottom of the crucible should be ≥10mm, and the distance between the probe cylinder and the crucible wall should be ≥10mm.
4.4 Torsion angle or viscosity detection device: Use a photoelectric pulse measurement system to measure the time difference △t of the hanging wire torsion angle (or use other systems to measure torque), and determine the viscosity n according to the known instrument constant K according to formula (1). The support mechanism or bracket system of the detection device is stable in lifting and rotating. 4.5 Standard viscosity liquid: This test method uses the standard viscosity liquid approved by the State Administration of Quality Supervision, Inspection and Quarantine to calibrate the instrument constant K. This standard recommends the following standard material numbers: GBW13605, GBW13606, GBW13607, GBW13608, GBW13609. 5 Sample preparation
Take the slag sample and carry out carbonization treatment at 500℃～900℃ in the atmosphere of the heating furnace. After treatment, the carbon content in the sample should be less than 0.5%.
6 Determination of instrument constants
Use beakers with the same size as the inner cavity size of the graphite used for the test to hold standard viscosity liquids of known viscosity, place the beakers in a constant temperature water bath, the position of the probe in the standard viscosity liquid in the beaker is consistent with its position in the slag in the crucible, the probe speed is the same as that in 4.3, and the time difference △t of the torsion angle of the hanging wire in the standard viscosity liquids of different viscosities\ is measured respectively. According to the principle of least squares method, the test data is regressed according to formula (1) to obtain the instrument constant K. At least three brands of standard viscosity liquids with a viscosity of 0.1Pa·s～1.0Pa·s at the calibration temperature should be used.
7 Test steps
7.1 Determination of the initial position of the probe: Use a beaker with the same size as the inner cavity of the graphite crucible used for the test to hold distilled water, insert the probe into the distilled water, rotate the probe, and the probe speed is the same as that in 4.3. When the probe rotates stably, record the time difference of the twist angle of the hanging wire as the time △t corresponding to the initial position of the probe 2
.
YB/T185—2001
7.2 Raise the temperature of the electric heating furnace to 1200℃～1400℃, add graphite to the sample prepared in Chapter 5, place the graphite crucible in the furnace, and add more samples after the sample is melted until the slag depth in the crucible reaches the requirement of 4.3 (generally 40mm～60mm). 7.3 Stabilize the furnace temperature at 1300℃±2℃, insert the probe into the furnace and preheat it about 100mm above the crucible for 2min, then insert the probe into the slag according to the requirements of 4.3 and rotate it. After the temperature stabilizes for 20min, record the readings continuously for not less than 43 times. Calculate the results and errors of the test data according to Chapter 8. Under the condition that the corresponding error requirements are met, the viscosity corresponding to the average value of the readings is taken as the viscosity of the sample at this temperature (1300℃).
7.4 If it is necessary to measure the viscosity of the sample at other temperatures, stabilize the furnace temperature at the corresponding temperature, and refer to 7.3 to measure the corresponding viscosity of the sample.
7.5 After the test is completed, lift the probe and take out the crucible. 8 Result calculation and deviation
8.1 Result calculation
Continuously test and record the viscosity data of not less than 43 times for the same sample at the same temperature, and calculate its average value and deviation S according to formula (2) and formula (3).
·（2）
—The number of times the viscosity is tested and recorded continuously, i=1, 2, 3., nn≥43; where: i-
nThe viscosity value of the ith test;
n——The total number of times the viscosity is tested and recorded continuously;
n——The average value of the viscosity tested continuously for n times; S——The deviation of the viscosity tested continuously for n times. 8.2 Test deviation
（3）
The calculation result shall retain three decimal places, and the numerical rounding rules shall be carried out in accordance with the provisions of GB/T8170. The deviation S shall not be greater than 0.010Pa·s.
9Test report
The test report should include the following contents:
a) Commissioning unit;
b) Sample name;
c) Sample delivery date;
d) Test date;bzxz.net
e) Test unit;
f) Instrument constant used in viscosity test;
g) Test temperature and average viscosity value;
h) Tester;
i) Auditor.
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