GOST 9454-78

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  ГОСТ 9454-78

GOST 9454−78 Metals. Test method for impact strength at low, room and elevated temperatures (with Amendments No. 1, 2)

GOST 9454−78

Group B09

STATE STANDARD OF THE USSR

METAL

Test method for impact strength at low,
room and elevated temperatures

Metals. Method for testing the impact strength at low
room and high temperature

AXTU 1909

Date of introduction 1979−01−01

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of ferrous metallurgy of the USSR

DEVELOPERS

V. N. Danilov, Dr. SC. Sciences; M. N. Georgiev, PhD. tech. science; N. Ya Mezhova; L. N. Kosarev, candidate. tech. Sciences; E. F. Komolova, PhD.tech. Sciences; B. A. Drozdov, Cand. tech. Sciences; V. G. Kudryashov, candidate. tech. Sciences; P. D. Odessa, Cand. tech. Sciences; V. I. Hermida, PhD. tech. Sciences; V. I. Zmievskaya, PhD. tech. Sciences

2. APPROVED AND promulgated by the decree of the State Committee of standards of Ministerial Council of the USSR from 17.04.78 N 1021

3. The standard fully complies with ISO 83−76 and ISO 148−83

4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

5. Limitation of actions taken by the decision of the Interstate Council for standardization, Metrology and certification (Protocol 3−93 from 17.02.93)

6. REPRINT (October 1993) with Amendments No. 1, 2 approved in October 1981, March 1988, (IUS 12−81, 6−88)

INSTEAD 9454−60 GOST, GOST and GOST 9455−60 9456−60.*
___________________
Cancellation of documents is shown from the publication: official publication, Moscow: Publishing house of standards, 1982. Note the «CODE».


This standard applies to ferrous and nonferrous metals and alloys, and specifies a method for testing the impact strength at temperature from minus 100 to + 1200 °C.

The method is based on the destruction of the sample with the hub in the middle with one blow of pendulum. The ends of the specimen is placed on supports. The test determine the total work expended at impact (the work stroke), or toughness.

Under toughness you should understand the work of the strike referred to the initial cross-sectional area of sample in place of the hub.

(Changed edition, Rev. N 1, 2).

1. SAMPLING METHOD

1.1. The shape and dimensions of samples for testing shall be as specified in the table and in hell. 1−3.

Dimensions, mm

_____________
* In the control test allowed the mass production of samples with a maximum deviation of ±0.10 mm.

Damn.1. The sample concentrator of U

Damn. 1

Damn. 2 .The sample concentrator V

Damn. 2

Damn 3. The sample concentrator of the form T (fatigue crack)

a — General view; b — shape of the concentrator for samples 15 to 19 of the type; in the form of a hub 20 for samples of the type

Damn. 3

Allowed to use samples without cut and with one and two untreated surfaces, the size of which in width are different from those in the table.

The scope of the reference samples specified in Annex 1.

Testing types 4, 14, 18 is performed according to user demand for products of special purpose.

1.2. Place tenderloin blanks for the manufacture of the samples, the orientation of the axis of the hub, the technology of cutting blanks and manufacture samples according to GOST 7565−81 for ferrous metals, unless otherwise provided for in the normative-technical documentation for the products.

For non-ferrous metals and alloys, all of this should be specified in normative and technical documentation for the products.

When cutting workpieces of metal samples should be protected from hardening and heating, changing of metal properties, unless otherwise specified in the normative-technical documentation for the products.

1.1; 1.2. (Changed edition, Unit No. 2).

1.3. Risks on the surface of the hub of the types U and V that are visible without using the magnifying means are not permitted.

1.4. Hub T get to the top of the initial incision in plane cyclic bending of the sample. A method of producing a primary concentrator can be anything.

The number of cycles necessary to obtain a crack of a given depth must be at least 3000.

1.5. The maximum residual deflection formed when applied to the sample concentrator. should not exceed: 0.25 mm — sample length of 55 mm.

Control of the deflection of the sample by using the dial indicators churchyard 577−68 or other means to ensure the accuracy of measurement of deflection of not more than 0.05 mm on the basis of the length of the specimen.

1.6. The type and number of samples, the procedure for re-testing must be specified in normative and technical documentation for specific products, duly approved.

If in the normative and technical documentation for metal products is not specified specimen type should be tested the samples of a type 1 — to 01.01.91.

1.4−1.6. (Changed edition, Rev. N 1, 2).

2. EQUIPMENT AND MATERIALS

2.1. Pendulum copra — GOST 10708−82. The speed of the pendulum at the moment of impact must be:

(5±0,5) m/s for copra with a nominal potential energy of the pendulum 50 (5,0); 150 (15); 300 (30,0) j (kgf·m);

(4±0,25) m/s for copra with a nominal potential energy of the pendulum 25 (2,5); 15 (1,5); 7,5 (0,75) j (kgf·m);

(3±0,25) m/s for copra with a nominal potential energy of the pendulum 5,0 (0,5) j (kgf·m) or less.

Copra is allowed to apply other nominal potential energy of the pendulum. The nominal value of the potential energy of the pendulum must be such that the value of the work impact was not less than 10% of the nominal value of the potential energy of the pendulum. Allowed to 01.01.91 to use copra with such nominal potential energy of the pendulum to the work of the blow was not less than 5% of the nominal potential energy of the pendulum. The nominal value of the potential energy of the pendulum must be specified in normative and technical documentation for specific products.

The principal dimensions of bearings and knife of the pendulum should correspond to those on features. 4. For ramming other design permitted additional radii of curvature of the rib supports and the speed of movement of the pendulum from 4.5 to 7.0 m/s.

(Changed edition, Rev. N 2).

Damn. 4. Support and knife pendulum

Damn. 4

2.2. Thermostat, providing uniform cooling or heating, no aggressive effects of the environment on the sample and temperature control.

2.3. A mixture of liquid nitrogen (GOST 9293−74) or solid carbon dioxide («dry ice») and ethanol. Use as a chiller liquid oxygen and liquid air are not allowed.

The mass fraction of oxygen in liquid nitrogen in the cooling process of the samples in the thermostat should not be more than 10%.

(Changed edition, Rev. N 1,2).

2.4. Thermometers with an accuracy of ±1 °C for measuring the temperature of the cooling medium.

2.5. Thermometers, including the thermoelectric transducers (thermocouples), to measure the temperature of heating of samples, providing measurement with an error not exceeding:

±5 °C at the heating temperature to 600 °C;

±8 °C, at a heating temperature of over 600 °C.

2.4, 2.5. (Changed edition, Rev. N 2).

2.6. Crack samples, get on the vibrators manufactured according to normative-technical documentation.

2.7. Calipers should meet the requirements of GOST 166−89. Allowed to use other measuring means for measuring with an error not exceeding specified in clause 1.1.

2.6, 2.7. (Added, Rev. N 2).

3. PREPARING FOR THE TEST

3.1. Before starting tests, check the position of the pointer of the free fall of the pendulum.

For the pendulum copra with digital reading devices the pointer in the initial position should show zero with the allowable deviation in the width of the stroke according to normative-technical documentation.

(Changed edition, Rev. N 1, 2).

3.2. The test temperature should be the temperature of the specimen at the moment of impact.

Test temperature point in the normative-technical documentation for specific products, duly approved.

3.3. Room temperature should be the temperature of (20±10) °C

3.4. To ensure the required temperature of test samples before installation on the rig needs to be supercooled (if the test temperature is below room temperature) or superheated (with test temperature above room). The degree of exposure to cold or heat must provide the required test temperature and should be determined experimentally.

Temperature hypothermia or overheating of the samples, provided that they can be tested no later than 3−5 s after extraction from the thermostat, indicated at reference Annex 2.

Aging samples in a thermostat at a given temperature (with the necessary cold or heat stress) must be at least 15 minutes.

(Changed edition, Rev. N 1).

3.5. In contact with the sample portion of the fixture to remove it from the thermostat should change the temperature of the sample when it is placed on the support copra.

4. TESTING

4.1. The sample should be free to lie on the supports of copra (see the devil. 4). The specimen installation should be done by the template, providing a symmetrical arrangement of the hub with respect to the supports with an accuracy of ±0.5 mm When using mechanical restraints should not interfere with the samples freely deform.

4.2. The test shall be carried out upon impact of the pendulum on the side opposite to the hub, in the plane of its symmetry.

4.3. The job impact is determined on a scale of pendulum or analog readout devices.

(Changed edition, Rev. N 2).

5. PROCESSING OF THE RESULTS

5.1. For test result take work strike or toughness for specimens with concentrators of types U and V and impact strength for samples with the hub view So

(Changed edition, Rev. N 2).

5.2. Work strike represent two letters (U, V or T) and numbers. The first letter () is a symbol of the work of the blow, the second letter (U, V, or T) is a kind of hub. The subsequent figures represent the maximum impact energy of the pendulum, the depth of the hub and the width of the specimen. The numbers do not point in the determination of the impact on Koper with a maximum impact energy of pendulum 300 (30,0) j (kgf·m) at a depth of 2 mm of hub hub types U and V, and 3 mm for the hub T and the width of the sample 10 mm (samples 1, 11 and 15).

Allowed to designate a work strike two indices (A):

the first (A) is a symbol of the work of impact, the second () is the type character pattern in accordance with the table.

(Changed edition, Rev. N 1).

5.3. The toughness denotes a combination of letters and numbers.

The first two letters of the COP represent a symbol of toughness, the third letter — type of hub; the first digit is the maximum impact energy of the pendulum, the second is the depth of the hub and the third is the width of the specimen. The figures do not indicate in the case specified in paragraph 5.2.

Allowed to denote the toughness of the two indexes (); first () is a symbol of toughness; the second () is the type character pattern in accordance with the table.

To refer to the work of impact and toughness at low and elevated temperature is introduced by the digital code indicating the test temperature. Digital index put at the top after the letter components.

For example:

V50/2/2 — work of impact, defined on the sample concentrator of V at a temperature of minus 40 °C. the Maximum energy of the pendulum impact 50 j, the depth of the hub 2 mm sample width 2 mm.

ST 150/3/7,5 — impact strength determined on a sample with a hub T at a temperature of 100 °C. the Maximum energy of the pendulum impact 150 j, the depth of the hub 3 mm, sample width 7.5 mm.

CU (CV) is the impact strength determined on a sample concentrator of U (V) at room temperature. The maximum impact energy of 300 j pendulum, the depth of the hub 2 mm, specimen width 10 mm.

 — impact strength determined on a sample of type 11 at a temperature of minus 60 °C. the Maximum impact energy of 300 j pendulum.

(Changed edition, Rev. N

1).

5.4. Impact strength (CS) in j/cm(kgf·m/cm) is calculated according to the formula

,

where is the job of the shock, j (kgf·m);

 — the initial cross-sectional area of sample in place of the hub, cm, calculated by the formula

,

where is the initial height of the working part of the specimen, cm;

 — initial sample width, see

and is measured with an accuracy of ±0.05 mm (±0,005 cm). round: the width of the sample 5 mm and less — to the third significant figure, when the width of the sample greater than 5 mm to the second significant digit.

For samples with the hub of the T-value is defined as the difference between the overall height measured to the test with an error no more than ±0.05 mm (±0,005 cm), and the calculated depth of the hub , measured by any optical means with a magnification of at least 7 on the fracture surface of the specimen after testing according to the scheme given on features. 5, with error not more than ±0.05 mm (±0,005 cm).

(Changed edition, Rev. N 1, 2

).

5.5. The value of KS in the record books rounded up to 1 (0,1) j/cm(kgf·m/cm) — set to COP more 10 (1) j/cm(kgf·m/cm); 0.1 (0.01) of j/cm(kgf·m/cm) — if the value is less than 10 KS (1) j/cm(kgf·m/cm).

(Changed edition, Rev. N 1

).

5.6. If the test sample is not completely destroyed, the measure of the quality of the material is not installed. In this case, the test report indicate that the sample with maximum impact energy of pendulum was not destroyed.

The results of the tests do not take into account if the fracture samples for defects of metallurgical production.

(Changed edition, Rev. N 2).

5.7. When replacing a sample the reason indicated in the test report.

5.8. The original data and the results of the sample test recorded in the test report. Form of the Protocol given in the recommended attachment 3.

Damn. 5

abc — the front of a fatigue crack; I-I-the position of the sighting line of the eyepiece of the microscope at the initial time of measurement (coincides with the face samples); II-II — position of the sighting line of the microscope at the end of the measurement (position II-II is selected so that the shaded area above the line would be equal to the unshaded area below the hairline)

Damn. 5

ANNEX 1 (reference). Application field samples

ANNEX 1
Reference

(Changed edition, Rev. N 1).

ANNEX 2 (informative). Temperature subcooling and superheat depending on the test temperature

ANNEX 2
Reference

APPENDIX 3 (recommended) TEST the IMPACT strength

APPENDIX 3
Recommended

Mark Kopra_____________________________________________________________

The maximum impact energy of pendulum when tested_________________________

The speed of the pendulum at the moment of impact__________________________________________ m/s

The subject material ___________________________________________________

(Changed edition, Rev. N 1).



The text of the document is verified by:
the official publication of the
M.: Publishing house of standards, 1994