GOST 11701-84

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  ГОСТ 11701-84

GOST 11701−84 Metals. Methods tensile tests of thin sheets and strips (with Amendments No. 1, 2)

GOST 11701−84

Group B09

STATE STANDARD OF THE USSR

METALS

Methods tensile tests of thin sheets and strips

Metals. Methods of tensile testing of thin sheets and strips

AXTU 0909

Date of introduction 1986−01−01

INFORMATION DATA

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

DEVELOPERS

V. I. Matorin, B. M. Ovsyannikov, V. D. Khromov, N. Berun, A. V. Minashin, E. D. Petrenko, V. I. Chebotarev, M. F. Gambus, V. G. Gachelin, A. V. Bogacheva

2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee for standards from 17.07.84 N 2514

3. The standard complies ST SEV 471−88 part of the testing sheets and strips of a thickness of from 0.5 to 3.0 mm

4. REPLACE GOST 11701−66

5. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

6. Validity extended until 01.01.96* Decree of Gosstandart of the USSR from 25.03.91 N 319
__________________
* Expiration removed by Protocol No. 5−94 of the Interstate Council for standardization, Metrology and certification. (IUS N 11−12, 1994). — Note the CODE.

7. REPRINT (February 1993) with Amendments No. 1, 2, approved in October 1987, March 1991 (ICS 1−88, 6−91)

This standard establishes methods of static tensile tests of thin sheets and strips of ferrous and non-ferrous metals with thickness up to 3,0 mm for the determination of temperature (20)°C characteristics mechanical properties:

the limit of proportionality;

the yield strength of the physical;

the yield strength of the conditioned;

temporary resistance;

relative uniform elongation;

the relative elongation after rupture.

The standard complies ST SEV 471−88 part of the testing sheets and strips of a thickness of from 0.5 to 3.0 mm.

Terms used in this standard, and explain to them — in accordance with GOST 1497−84.

(Changed edition, Rev. N 2).

1. SAMPLING METHODS

1.1. The cutting blanks for samples and production samples carried out according to GOST 1497−84.

1.2. For the test used a proportional flat samples with an initial estimated length or , for testing sheets and strips of a thickness of from 0.5 to 3.0 mm and .

The type and size of samples must be specified in normative and technical documentation on the rules of selection of blanks and samples or products.

If there are indications in the normative-technical documentation for metal products is permitted to test the tape subject to the tolerances envisaged for the test of metal. When the width of the test tape less than 12.5 mm initial gauge length shall be not less than 50 mm.

Not allowed straightening of blanks or samples, the deformation or bending their local inflection.

1.3. Shape, dimensions and limit deviations of width proportional flat samples are given in mandatory Appendix 1.

If there are indications in the normative-technical documentation for metal products is permitted to use a proportional flat samples of other sizes.

1.4. The working length of the samples shall be from to .

The differences in the assessment of the quality of the metal working length of the samples needs to be .

Note. When using strain gauges or testing machine with automatic determination of elongation after rupture of the working part and the estimated lengths of the sample shall conform to the requirements of GOST 1497−84.


(Changed edition, Rev. N 2).

2. EQUIPMENT

2.1. Tensile and universal testing machine according to GOST 28840−90.

2.2. Calipers, micrometers — according to GOST 1497−84.

Allowed to use other measuring devices that provide measurement with an uncertainty not exceeding the specified in paragraph 3.2.

2.3. The strain gauges relative price of division — according to GOST 1497−84.

(Changed edition, Rev. N 2).

3. PREPARING FOR THE TEST

3.1. Set the initial estimated length limit with an error of up to 1% on the working part of the sample cores, risk, or other marks, excluding damage to the sample surface.

To recalculate the relative elongation after rupture with attributing the break to the middle and to determine the relative uniform elongation along the entire working length of the sample it is recommended to apply risk, cores or other markers every 5 or 10 mm.

3.2. The error in determining the initial cross-sectional area should not exceed ±2% (at the limit of measurement error of the width of the sample to ±0.2%).

(Changed edition, Rev. N 2).

3.3. Measuring dimensions of samples before testing is carried out in at least three places — in the middle part and on the borders of the working length of the specimen.

For the initial cross-sectional area of the specimen in its working parts take the lesser of the received values on the basis of the measurements with the rounding table.2.

Table 2*

_________________
* Table.1. (Deleted, Rev. N 2).

mm

The initial cross-sectional area of the tape , mm, obtained by flattening of the wire is calculated by the formula

where is the least thickness, mm;

 — the smallest width, mm.

3.4. The measurement of the initial and final estimated length is held by the caliper when the value read by Vernier to 0.1 mm.

3.5. The samples mark on the heads or sections to capture.

4. TESTING AND PROCESSING OF RESULTS

4.1. The definition of the limit of proportionality , yield stress of the physical , the yield strength of the conditioned (or otherwise established tolerance), strength and relative elongation after rupture is carried out at the test samples is proportional to n. 1.2. Testing and processing of results — in accordance with GOST 1497−84.

Determination of relative uniform elongation is carried out on samples with an initial estimated length according to GOST 1497−84.

4.2. Rounding of the calculated results of tests carried out in accordance with the table.3.

Table 3

4.1; 4.2. (Changed edition, Rev. N 2).

4.3. Allowed determination of the coefficient of plastic anisotropy , increased strain hardening and nonuniformity of plastic deformation . The definition of the characteristics of mechanical properties and example definitions are given in Appendix 2.

4.4. The results of the tests are recorded in accordance with GOST 1497−84 with the addition of: at break of the sample at a distance less than ¼ from the nearest label, the calculated limiting length.

4.5. When applying the samples, the initial estimated length of which or , elongation denoted by the symbols or .

When applying the samples, the initial calculated length of the symbol denoted by the symbol, denoting the initial estimated length of the specimen , in millimeters.

For example, or the elongation after rupture with the initial design length of 50 or 80 mm, a width of 12.5 or 20 mm, respectively.

Comparison of values of relative elongation after rupture proportional samples are only possible in cases where the initial gauge length and initial cross-sectional area compared samples are the same or both have the same coefficient of proportionality equal to, for example, against .

(Revised edition, Edit

. N 2).

4.6. The test results recorded in the Protocol, the form of which is given in Annex 3.

ANNEX 1 (recommended). PROPORTIONAL FLAT SAMPLES

ANNEX 1
Recommended

Damn.1. Proportional samples with the heads

Proportional samples with the heads

Damn.1

Table 1

mm

Damn.2. Proportional samples without heads

Proportional samples without heads

Damn.2

Table 2

mm

Notes:

1. Samples of heads are used mainly when testing high-strength materials with high brittleness and hardness, to avoid slippage of the sample, as well as the premature destruction of it in the grips of the testing machine.

2. Heads sizes are optional and depend on the method of mounting the sample in the testing machine.


In the samples having a head with holes with a diameter = 20 mm when = 20 mm and = 50 mm or a diameter of 15 mm at a = 12.5 mm and = 30 mm, the deviation of the hole centers from the axis of the sample are allowed not more than 0.05 mm.

Table 3

Limit deviations of the dimensions of the samples

mm

(Changed edition, Rev. N 2).

APPENDIX 2 (recommended). Determination of the COEFFICIENT of PLASTIC ANISOTROPY R, the STRAIN HARDENING INDEX n AND the UNEVEN PLASTIC deformation of A

ANNEX 2
Recommended

DETERMINATION OF THE COEFFICIENT OF PLASTIC ANISOTROPY,
INCREASED STRAIN HARDENING
AND UNEVEN PLASTIC DEFORMATION

1. Terms used in Annex 2 and explanations of them

(Changed edition, Rev. N 2).

2. Characteristics , , determined by the formula:

3. Rounding characteristics , that are produced in accordance with the table.

4. Example.

The test material is low carbon sheet steel; = 40%, = 10%, = 17%.

Sample size: width = 12.5 mm, thickness = 0.8 mm initial gauge length mm taken = 80 mm.

Determined by the estimated length of the strain gauge:

=4·12,5=50 mm;

=50 (1+0,01·10)=55 mm;

=50 (1+0,01·17)=58,5 mm.

The initial estimated length of specimen =80 mm divided into 8 plots application ticks using 10 mm.

Measure with a micrometer the width of the working part of the specimen before testing in the middle part and on the borders of the working lengths determined by the initial width of the working part of the specimen as the arithmetic mean of the three measurements:

mm.

Mounted on the sample strain gauges and produce the loading of the sample. Upon reaching the strain gauge value , is equal to 55 mm, fix the load equal to 3030 N (310 kgf).

Upon further loading the sample, we fix the load corresponding to the calculated length = 3150 H (325 kgf). Define the width of the parts of the sample and :

mm;

mm.

We get: = of 11.37 mm, a =11,30 mm.

The computed coefficient of plastic anisotropy :

after rounding = 1,98.

A calculated rate of strain hardening :

The calculated nonuniformity of plastic deformation :

after rounding = 5.7 percent.

(Changed edition, Rev. N 2).

APPENDIX 3 (reference). The PROTOCOL for tensile testing of flat specimens on the machine

APPENDIX 3
Reference

PROTOCOL N ________

tensile tests on flat samples ___________ by car __________

The text of the document is verified by:
the official publication of the
M.: standards Publishing house, 1993