GOST 23273-78
GOST 23273−78 Metals and alloys. Hardness measurement by the method of elastic rebound of the striker (shore a) (Change No. 1)
GOST 23273−78
Group B09
STATE STANDARD OF THE USSR
METALS AND ALLOYS
Hardness measurement by the method of elastic rebound of the striker
(shore a)
Metals and alloys.
Measurement of Shore hardness (method of striker recoil)
AXTU 0909
Date of introduction 1980−01−01
APPROVED AND put INTO EFFECT by decision of the USSR State Committee on standards of 13 September 1978, No. 2494
Resolution of the state standard from
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* Expiration removed by Protocol No. 7−95 Interstate Council for standardization, Metrology and certification (I & C N 11, 1995). — Note the CODE.
REPRINT (March 1987) with amendment No. 1, approved in April 1984 (IUS 7−84).
This standard applies to metals, alloys and metal products and sets the method for measuring the shore hardness of 20 to 140 units (HSD) at a temperature of (20)°C.
1. SAMPLING METHOD
1.1. Weight of the product when measuring hardness, installed directly to the product, shall be not less than 5 kg. Samples installed on the table of hardness, must have a mass of at least 0.1 kg and a thickness of not less than 10 mm.
2. EQUIPMENT
2.1. A device for measuring the hardness must provide:
the rebound height of the striker to 100 units of shore hardness — (13,6±0,3) mm;
the drop height of the striker — (19,0±0,5) mm;
the price of division of the dial gauge (measuring the rebound height of the striker) — not more than 1 scale units HSD.
Geometric dimensions and mass of the striker of the diamond should correspond to GOST 9377−81.
Periodic calibration of the hardness tester is produced according to normative-technical documentation.
The current calibration of hardness produce exemplary measures according to normative-technical documentation.
(Changed edition, Rev. No. 1).
3. PREPARING FOR THE TEST
3.1. The surface of the test products or of the sample should be free from oil and dirt, have a roughness of not more than = 2.5 µm according to GOST 2789−73.
3.2. The surface of the table, which placed the test product or sample must be smooth, free from oil and dirt.
The device sets vertically on a level (GOST 3059−75) mounted in the housing.
Flat items or samples placed directly on a table, drum — set on the base with a V-neck.
3.3. Products of large dimensions experience with a removable part of the device. The device is set vertically product horizontally level. It is recommended to use the stand-prism to installation of the removable part of the device on the product.
4. TESTING
4.1. The test shall be performed on a variety of metal products (e.g. steel and cast iron mill rolls) and samples of various forms.
4.2. In the measurement of shore hardness the hammer of a certain mass with a diamond tip freely and vertically falls from a certain height on the test surface. The height of rebound of the striker is treated as a characteristic of hardness and is measured in arbitrary units (Fig. 2).
Damn. 2*
Damn. 2*
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* Hell. 1 excluded.
4.3. When measuring hardness must be complied with the following conditions:
horizontal installation (sample);
tight adherence of the cap of the device to the test surface;
the speed test should be no more than 5 attacks in 10 seconds.
4.4. The product or sample should lie on the table firmly, steadily, to avoid displacement during testing.
4.5. The distance between two adjacent prints from the edge of the sample or item to imprint must be at least 2 mm.
4.6. On the site of the product or sample to be the hardness should be not less than five measurements. The arithmetic mean of these measurements taken as the hardness of this product or sample, provided that the difference between the largest and smallest numbers these indications of hardness does not exceed 5 units. If the measurement results differ more than 5 units, the test is repeated, the number of prints at the same dual.
4.7. During the test the device must be protected from the effects of shock and vibration.
4.8. Hardness shore point rounded to whole units of the scale HSD.
4.9. (Deleted, Rev. No. 1).
4.10. The shore hardness HSD designated index, for example, 85HSD.
4.11. (Deleted, Rev. No. 1).
4.12. The value of shore hardness is not the exact method of its translation into other hardness value or the tensile strength.
The text of the document is verified by:
the official publication of the
M.: Publishing house of standards, 1988
