GOST 8.509-84

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  ГОСТ 8.509-84

GOST 8.509−84 State system of ensuring unity of measurements (GSI). Machines for testing metals for long-term strength and creep. Verification procedure

GOST 8.509−84

Group Т88.1*__________________________________________

* In the index «National standards» in 2007.
group Т88.2. — Note the manufacturer’s database.

STATE STANDARD OF THE USSR

State system for ensuring the uniformity of measurements

MACHINES FOR TESTING METALS
LONG-TERM STRENGTH AND CREEP

Verification procedure

State system for ensuring the uniformity of measurements.
Long-term strength and creep testing machines. Calibration methods

AXTU 0008

Date of introduction 1986−01−01

DEVELOPED by the State Committee of USSR on standards

PERFORMERS

N. With. Chalenko (theme leader), Vladimir Korshun-Osmolovsky

MADE with the USSR State Committee for standards

Member Of The State Standard L. K. Isaev

APPROVED and put INTO EFFECT by Decision of the USSR State Committee for standards from August 27, 1984 N 3012

INSTEAD of guidance 271

This standard applies to machines for testing metals and alloys for long-term strength and creep GOST 15533−80 as the means of measurements of linear deformations of these materials, and establishes the methodology of their initial and periodic verifications.

The standard does not apply to machines with maximum permissible relative error of load application to the specimen of 0.5%.

1. VERIFICATION OPERATIONS

1.1. During the verification should be performed following operations:

external inspection (p. 5.1);

approbation (n.5.2);

the definition of the metrological characteristics (n.5.3);

the definition of the average speed of the active capture machine (p. 5.3.1);

determination of the error of load application to the specimen (n.5.3.2);

error determination regulate the temperature of the furnace (p. 5.3.3).

2. MEANS OF VERIFICATION

2.1. During verification, apply the following calibration instruments:

model portable dynamometers 3rd category according to GOST 9500−75* corresponding to the verified range of the machine;
______________
* On the territory of the Russian Federation GOST 9500−84. — Note the manufacturer’s database.

calipers with divisions of 0.05 mm according to GOST 166−80;
______________
* On the territory of the Russian Federation GOST 166−89. — Note the manufacturer’s database.

optical quadrant type К01 according to GOST 14967−80;

mechanical stopwatch with GOST 5072−79;

thermoelectric thermometers (test machine);

reduction sleeves with double thread for connection test machine to a dynamometer (test machine).

All of the above calibration instruments must have valid calibration certificates (certification).

3. CONDITIONS VERIFICATION

3.1. During the verification must meet the following conditions:

the machine must be installed indoors in accordance with the technical documentation (hereafter NTD);

the ambient temperature must be (20±5) °C. the temperature during the calibration should not change by more than 3 °C. When the deflection temperature calibration by more than 3 °C from the temperature at which carried out the calibration of the dynamometer, in his testimony introduce an amendment according to GOST 8.287−78;

relative humidity (65±15)%;

there should be no external sources of vibration, causing visible fluctuations of pointers indicating device of the dynamometer.

4. PREPARING FOR CALIBRATION

4.1. Before carrying out the verification must be completed the following preparatory work.

4.1.1. Check installation of the machine in two mutually perpendicular vertical planes with the help of a quadrant, the slope may be no more than 15'.

4.1.2. The standard means before calibration needs to be maintained in terms of checking at least 4 hours.

4.1.3. Establish exemplary dynamometer in the grips of the machine (reading device set at the zero position) and pre-loaded with a force equal to the upper limit of the measurement dynamometer or maximum limit load machine, if the latter is smaller values .

The dynamometer is kept under this load for the time specified in the reference document on the dynamometer.

After unloading the exemplary reading device of the dynamometer was again set to zero.

Note. Exemplary pre-loading of the dynamometer is carried out immediately before the definition of the metrological characteristics.

5. VERIFICATION

5.1. At external examination, you should have verified compliance of the machine with the following requirements.

5.1.1. Machine parts, mechanisms and components should not have corrosion and mechanical damage affecting its normal operation.

5.1.2. Installation of the furnace and the thermostat must be performed in accordance with the NTD instructions to check the car.

5.2. Testing checks the interaction of measuring deformation with a device that transmits the deformation of the sample on the probe.

5.3. Determination of metrological characteristics

5.3.1. The average speed of the active capture from one extreme position to the other , mm/s, calculated by the formula

,

where  — the distance to move active engagement, mm;

 — the time displacement of the active capture, p

The speed should not exceed values specified in GOST 15533−80.

5.3.2. In determining the error of the load application to the specimen is carried out a number of exemplary dynamometer loadings, with five stages, evenly distributed over the measuring range of the machine. This should include the highest and lowest limit load. At each stage conduct a reference load according to the testimony of exemplary dynamometer. The operation is performed three times.

Relative error of load application to the specimen , %, at each stage of loading is determined by the formula

,

where  — the load on the stage;

 — the arithmetic mean of the three measurements, measured on a scale of exemplary dynamometer on stage.

The value of the relative error for each level should not exceed the limit stated in the reference document to check the car.

5.3.3. The control deviation of the temperature regime of the furnace is determined on the lower and upper limits of the operating range of the furnace temperature. Thermoelectric transducers (3 PCs) thermoelectric thermometers (kit cars) have evenly along the length of the furnace on the highest calculated length of sample for test machines (including against the ends of the specimen). After reaching furnace temperature, equal to the lower limit of the working range (limit of acceptable deviation of ±1 °C), the thermostat is set to the regulation. Oven at the prescribed temperature is maintained for 5 h ±0,12 h; then measure the temperature in the oven every 15 min for 1 h. the Measurement at the upper limit is carried out in the same way as at the bottom. For the control deviation take greatest of the following differences between the set temperatures and the corresponding measurement results. The control deviation must not exceed maximum permissible values specified in GOST 15533−80.

5.3.4. Practice multiple-machines is carried out in each partition individually.

6. THE RESULTS OF THE VERIFICATION

6.1. Machines that pass the test with positive results, found fit for use, and they issue a certificate on state verification in the prescribed form to be applied on machine print verification seal.

6.2. The measurement results are entered into the Protocol, the form of which is given in mandatory Appendix.

6.3. Machines that pass the test with negative results, to use is not allowed. The certificate void. The mark of the previous verification stub.

APP (mandatory). PROTOCOL of calibration of testing machines

APP
Mandatory

Determine the relative error of the load application

Determination of errors temperature control

The electronic text of the document
prepared by JSC «Code» and checked by:
the official publication of the
M.: Publishing house of standards, 1984