By Decree of the USSR State Committee on Standards dated May 16, 1980 No. 2160, the introduction date was set
01.07.82
This standard establishes a method for testing the torsion at temperature of round wires made of metals and alloys with a diameter of 0.20 to 10 mm and shaped wires with cross-sectional areas corresponding to these diameters.
1. SAMPLING METHOD
1.1. The method of selecting samples for torsion testing is specified in the regulatory and technical documentation for the wire.
1.2. The length of the test part of the sample, i.e. the distance between the grips of the machine must correspond to that given in the table. 1.
Table 1
It is allowed to use wire with a different sample length in accordance with the regulatory and technical documentation for the wire.
When testing shaped wire torsion, the length of the sample should be equal to the length of round wire samples of equal cross-sectional area.
It is allowed to test wire with a diameter of less than 0.20 mm according to the test conditions for a diameter of 0.20 mm.
(Changed edition, Amendment No. 1)
2. EQUIPMENT
2.1. Machines that meet the following requirements are used as testing equipment.
2.1.1. The gripping jaws must have a hardness of at least 62 HRC e (61 HRC). The jaws of the grippers may have a notch that does not cause destruction of the sample in the grippers of the machine.
2.1.2. The machine's grippers must be aligned.
Deviation from alignment should not exceed 1 mm with a distance between grips of 100 mm.
2.1.1.-2.1.2. (Changed edition, Amendment No. 1)
2.1.3. One of the machine's grippers must rotate around an axis without moving along the center line, the other must have only longitudinal movement.
2.1.4. The gripper, which has longitudinal movement along the axis, must have a device for tensioning the test sample,
2.1.5. The machine must have a readout device for the number of revolutions of the active gripper and a scale that allows you to set the desired distance between the grippers.
2.1.6. The machine must provide the ability to change the direction of torsion six times when testing a sample for torsion at a given rotation speed. The number of twists in the original direction must be at least three.
3. PREPARATION FOR THE TEST
3.1. Before testing, it is allowed to straighten the samples, which should not affect the state of the surface and the shape of the wire section.
3.2. The sample must be secured in the machine in such a way that its longitudinal axis coincides with the axis of the grips and that the sample does not rotate during testing.
4. CONDUCT OF THE TEST
4.1. A pre-tension must be applied to the wire sample, the value of which should not exceed 2% of the breaking force.
4.2. When testing, the rotation speed of the gripper must comply with the requirements of Table. 2.
table 2
4.3. One full rotation of the active grip of the machine is taken as one twist.
4.4. If the destruction of the sample occurred in the grips of the machine or near the grips (at a distance of less than 2 d) and the sample did not withstand the required number of twists, then the test must be repeated on another sample.
4.5. In accordance with the requirements of regulatory and technical documentation for wire, the following types of tests and controls can be carried out:
twisting with a change in the direction of torsion;
twisting two samples folded side by side (double twisting);
torsion with determination of the nature of the fracture and the condition of the samples after the torsion test.
(Changed edition, Amendment No. 2)
4.6. It is allowed to test the wire in accordance with the requirements of Table. 3 to 07/01/98.
Table 3
For other lengths of the test part of the sample, the rotation speed changes in direct proportion to the change in the length of the test part of the sample.
(Changed edition, Amendment No. 1, 3).
5. PROCESSING RESULTS
5.1. The test result is taken to be the number of twists that the sample can withstand before failure or without destruction up to a given number of twists.
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the USSR Ministry of Ferrous Metallurgy
2 APPROVED AND ENTERED INTO EFFECT by Resolution of the USSR State Committee for Standards dated May 16, 1980 No. 2160
Change No. 3 was adopted by the Interstate Council for Standardization, Metrology and Certification (Minutes No. 6 of October 21, 1994)
|
State name |
Name of the national standardization body |
|
The Republic of Azerbaijan |
Azgosstandart |
|
Republic of Armenia |
Armgosstandard |
|
Republic of Belarus |
State Standard of Belarus |
|
Gruzstandart |
|
|
The Republic of Kazakhstan |
Gosstandart of the Republic of Kazakhstan |
|
Kyrgyz Republic |
Kyrgyzstandard |
|
The Republic of Moldova |
Moldovastandart |
|
Russian Federation |
Gosstandart of Russia |
|
The Republic of Uzbekistan |
Uzgosstandart |
|
State Standard of Ukraine |
4. The validity period was lifted according to Protocol No. 7-95 of the Interstate Council for Standardization, Metrology and Certification (IUS 11-95)
5. EDITION with Amendments No. 1, 2, 3, approved in January 1987, November 1990, June 1996 (IUS 5-87, 2-91, 9-96)
State standard of the USSR GOST 1545-80
"WIRE. TORSION TEST METHOD"
Wire. Torsion test method
With changes:
Duration limitation removed in 1995.
Instead of GOST 1545-63
This standard establishes a method for testing torsion at a temperature of 20°C of round wire made of metals and alloys with a diameter of 0.20 to 10 mm and shaped wire with cross-sectional areas corresponding to these diameters.
1. Sampling method
1.1. The method of selecting samples for torsion testing is specified in the regulatory and technical documentation for the wire.
1.2. The length of the test part of the sample, i.e. the distance between the grips of the machine must correspond to that given in the table. 1.
Table 1
It is allowed to use wire with a different sample length in accordance with the regulatory and technical documentation for the wire.
When testing shaped wire torsion, the length of the sample should be equal to the length of round wire samples of equal cross-sectional area.
It is allowed to test wire with a diameter of less than 0.20 mm according to the test conditions for a diameter of 0.20 mm.
2. Equipment
2.1. Machines that meet the following requirements are used as testing equipment.
2.1.1. The gripping jaws must have a hardness of at least 62 HRC. (61 HRС). The jaws of the grippers may have a non-cut that does not cause destruction of the sample in the grippers of the machine.
2.1.2. The machine's grippers must be aligned.
Deviation from alignment should not exceed 1 mm with a distance between grips of 100 mm.
2.1.3. One of the machine's grippers must rotate around an axis without moving along the center line, the other must have only longitudinal movement.
2.1.4. The gripper, which has longitudinal movement along the axis, must have a device for tensioning the test sample.
2.1.5. The machine must have a readout device for the number of revolutions of the active gripper and a scale that allows you to set the desired distance between the grippers.
2.1.6. The machine must provide the ability to change the direction of torsion six times when testing a sample for torsion at a given rotation speed. The number of twists in the original direction must be at least three.
3. Preparation for the test
3.1. Before testing, it is allowed to straighten the samples, which should not affect the state of the surface and the shape of the wire section.
3.2. The sample must be secured in the machine in such a way that its longitudinal axis coincides with the axis of the grips and that the sample does not rotate during testing.
4. Conducting the test
4.1. A pre-tension must be applied to the wire sample, the value of which should not exceed 2% of the breaking force.
4.2. When testing, the rotation speed of the gripper must comply with the requirements of Table. 2.
table 2
4.3. One full rotation of the active grip of the machine is taken as one rotation.
4.4. If the destruction of the sample occurred in the grips of the machine or near the grips (at a distance of less than 2 d) and the sample did not withstand the required number of twists, then the test must be repeated on another sample.
4.5. In accordance with the requirements of regulatory and technical documentation for wire, the following types of tests and controls can be carried out:
twisting with a change in the direction of torsion;
twisting two samples folded side by side (double twisting);
torsion with determination of the nature of the fracture and the condition of the samples after the torsion test.
4.6. It is allowed to test the wire in accordance with the requirements of Table. 3 to 07/01/98.
Table 3
For other lengths of the test part of the sample, the rotation speed changes in direct proportion to the change in the length of the test part of the sample.
5. Processing of results
5.1. The test result is taken to be the number of twists that the sample can withstand before failure or without destruction up to a given number of twists.
GOST 1545-80
Group B79
INTERSTATE STANDARD
WIRE
Torsion test method
Wire. Torsion test method
MKS 77.140.65
OKSTU 1209
Date of introduction 1982-07-01
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the USSR Ministry of Ferrous Metallurgy
2. APPROVED AND ENTERED INTO EFFECT by Resolution of the USSR State Committee on Standards dated May 16, 1980 N 2160
Change No. 3 was adopted by the Interstate Council for Standardization, Metrology and Certification (Minutes No. 6 of October 21, 1994)
The following voted for adoption:
State name | Name of the national authority |
The Republic of Azerbaijan | Azgosstandart |
Republic of Armenia | Armgosstandard |
Republic of Belarus | State Standard of Belarus |
Georgia | Gruzstandart |
The Republic of Kazakhstan | Gosstandart of the Republic of Kazakhstan |
Kyrgyz Republic | Kyrgyzstandard |
The Republic of Moldova | Moldovastandard |
Russian Federation | Gosstandart of Russia |
The Republic of Uzbekistan | Uzgosstandart |
Ukraine | State Standard of Ukraine |
3. INSTEAD GOST 1545-63
4. The validity period was lifted according to Protocol N 7-95 of the Interstate Council for Standardization, Metrology and Certification (IUS 11-95)
5. EDITION with Amendments No. 1, 2, 3, approved in January 1987, November 1990, June 1996 (IUS 5-87, 2-91, 9-96)
This standard establishes a method for testing torsion at a temperature of 20 °C of round wire made of metals and alloys with a diameter of 0.20 to 10 mm and shaped wire with cross-sectional areas corresponding to these diameters.
1. SAMPLING METHOD
1. SAMPLING METHOD
1.1. The method of selecting samples for torsion testing is specified in the regulatory and technical documentation for the wire.
1.2. The length of the test part of the sample, i.e. the distance between the grips of the machine must correspond to that given in Table 1.
Table 1
Nominal sample diameter | Length of the tested part of the sample |
From 0.20 to 0.25 incl. | |
St. 0.25 " 0.99 " | |
" 0,99 " 4,99 " | |
" 4,99 " 10,00 " |
It is allowed to use wire with a different sample length in accordance with the regulatory and technical documentation for the wire.
When testing shaped wire torsion, the length of the sample should be equal to the length of round wire samples of equal cross-sectional area.
It is allowed to test wire with a diameter of less than 0.20 mm according to the test conditions for a diameter of 0.20 mm.
(Changed edition, Amendment No. 1).
2. EQUIPMENT
2.1. Machines that meet the following requirements are used as testing equipment.
2.1.1. The gripping jaws must have a hardness of at least 62 HRC (61 HRC). The jaws of the grippers may have a notch that does not cause destruction of the sample in the grippers of the machine.
2.1.2. The machine's grippers must be aligned.
Deviation from alignment should not exceed 1 mm with a distance between grips of 100 mm.
2.1.1, 2.1.2. (Changed edition, Amendment No. 1).
2.1.3. One of the machine's grippers must rotate around an axis without moving along the center line, the other must have only longitudinal movement.
2.1.4. The gripper, which has longitudinal movement along the axis, must have a device for tensioning the test sample.
2.1.5. The machine must have a readout device for the number of revolutions of the active gripper and a scale that allows you to set the desired distance between the grippers.
2.1.6. The machine must provide the ability to change the direction of torsion six times when testing a sample for torsion at a given rotation speed. The number of twists in the original direction must be at least three.
3. PREPARATION FOR THE TEST
3.1. Before testing, it is allowed to straighten the samples, which should not affect the state of the surface and the shape of the wire section.
3.2. The sample must be secured in the machine in such a way that its longitudinal axis coincides with the axis of the grips and that the sample does not rotate during testing.
4. CONDUCT OF THE TEST
4.1. A pre-tension must be applied to the wire sample, the value of which should not exceed 2% of the breaking force.
4.2. When testing, the rotation speed of the gripper must comply with the requirements of Table 2.
table 2
Rotation speed, min, no more |
|
From 0.20 to 0.99 incl. | |
St. 0.99" 3.59" | |
" 4,99 " 10,00 " |
4.3. One full rotation of the active grip of the machine is taken as one twist.
4.4. If the destruction of the sample occurred in the grips of the machine or near the grips (at a distance of less than 2) and the sample did not withstand the required number of twists, then the test must be repeated on another sample.
4.5. In accordance with the requirements of regulatory and technical documentation for wire, the following types of tests and controls can be carried out:
twisting with a change in the direction of torsion;
twisting two samples folded side by side (double twisting);
torsion with determination of the nature of the fracture and the condition of the samples after the torsion test.
(Changed edition, Amendment No. 2).
4.6. It is allowed to test the wire in accordance with the requirements of Table 3 until 07/01/98.
Table 3
Nominal sample diameter, mm | Length of the tested part of the sample, mm | Rotation speed, min, |
From 0.20 to 0.99 incl. | 100, but not less than 50 | |
St. 0.99" 3.59" | and no more than 500 | |
" 3,59 " 10,00 " |
For other lengths of the test part of the sample, the rotation speed changes in direct proportion to the change in the length of the test part of the sample.
(Changed edition, Amendment No. 1, 3).
5. PROCESSING RESULTS
5.1. The test result is taken to be the number of twists that the sample can withstand before failure or without destruction up to a given number of twists.
The text of the document is verified according to:
official publication
Metal wire. Part 3: Sat. GOST. -
M.: IPK Standards Publishing House, 2003
GOST R 50708-94
(ISO 9649-90)
Group B79
STATE STANDARD OF THE RUSSIAN FEDERATION
WIRE
Alternating torsion test method
Wire. Reverse torsion test
MKS 77.040.10
77.140.65
OKP 12 0100
Date of introduction 1996-01-01
Preface
1 DEVELOPED AND INTRODUCED by the Technical Committee TC 146 "Hardware"
2 ADOPTED AND ENTERED INTO EFFECT by Resolution of the State Standard of Russia of November 8, 1994 N 266
3 This standard contains the full authentic text of the international standard ISO 9649-90 "Metallic materials. Wire. Alternating torsion test" with additional requirements reflecting the needs of the national economy
4 INTRODUCED FOR THE FIRST TIME
5 REISSUE
1 area of use
1 area of use
This standard establishes a method for determining the ability of metal wire with a diameter of 0.3 to 10 mm to undergo plastic deformation under alternating torsion. This test is carried out to identify surface and internal defects in the wire.
Additional requirements reflecting the needs of the national economy are written in italics.
2 Normative references
GOST 1545-80 Wire. Torsion test method
3 Symbols and definitions
Wire designations are shown in Figure 1 and Table 1.
Picture 1
Table 1
Designation | Definition | Unit |
Round wire diameter | ||
Length of the tested part of the sample (distance between grips) | ||
Number of twists in one direction |
4 Essence of the method
The wire sample is twisted a certain number of times 360° around its axis in one direction and the same number of times 360° in the opposite direction.
5 Test equipment
5.1 The grips shall be hard to provide rigidity and resistance to abrasion and shall be mounted on the machine so that they remain aligned during testing and do not subject the specimen to bending forces.
5.2 The machine must be designed in such a way as not to prevent the distance between the grips from changing during the test.
5.3 One of the machine grips must rotate around an axis, the other must not have angular deviations, except in cases where such deviations are necessary for measuring torque.
5.4 The distance between the grips should be adjusted depending on the length of the sample.
5.5 The testing machine shall be constructed in such a way that the required tensile stress in accordance with 7.2 can be applied to the test piece.
5.6 The machine must provide the ability to change the direction of torsion.
6 Procedure for preparing samples for testing
6.1 The piece of wire used as a sample must be straight.
6.2 If necessary, the sample is straightened manually, or, if this is not possible, using a hammer made of wood, plastic or copper on a flat surface of the same material.
6.3 When straightening, the surface of the wire should not be damaged and the test sample should not be subject to torsion.
6.4 Wire with sharp local curvature should not be used as a test sample.
6.5 Unless otherwise specified in the relevant standard, the distance between grips (nominal) shall be as specified in Table 2.
table 2
In millimeters
Nominal wire diameter | Jaw spacing (nominal) |
*50 can be applied by special agreement. ** 30 can be applied by special agreement. A fixed distance between grips can be established, which is specified in the relevant standard and recorded in the test report. |
|
7 Test procedure
7.1 Tests must be carried out at ambient temperatures from 10 to 35 °C.
Arbitration tests are carried out at a temperature of (25±5) °C.
7.2 The sample is secured in the grips in such a way that its longitudinal axis coincides with the axis of the grips and that it remains straight throughout the test. Unless otherwise specified in the relevant standard, this may be achieved by applying to the wire specimen a constant tensile stress sufficient to straighten the specimen, the value of which shall not exceed 2% of the rated tensile strength.
7.3 After securing the test sample in the machine, one of the grips must rotate at a speed not exceeding one revolution per second for wire diameters less than 5 mm and 0.5 revolutions per second for wire diameters 5 mm or more. The number of turns in one and opposite directions must be specified in the relevant wire standard.
One twist takes a rotation of 360°.
After completion of the test, the surface of the sample between the grips is checked visually, unless otherwise specified in the relevant standard.
7.4 The absence of visible defects is grounds to consider that the sample has passed the test.
7.5 If the destruction of the sample occurred in the grip of the machine or near the grips (at a distance of less than 2) and the sample did not withstand the required number of twists, then the result of this test is not taken into account. The test must be repeated on another sample taken from the same skein (spool) of which the sample failed.
8 Test report
8.1 The test report must contain:
a) the number of this standard;
b) characteristics of the test sample;
c) sample diameter;
d) method of editing the sample;
e) test conditions (for example, length of the test part of the sample, tensile stress);
f) test results.
The torsion test is used to evaluate the metal of shafts or wires, and to determine the mechanical strength and ductility characteristics of high-strength metals.
The essence of the method: one end of the sample is fixed motionless, and a couple of forces are applied to the other end in a plane perpendicular to the axis of the sample, which causes a torque M = F/d, Where F- effective force, MPa (kgf/mm), d- sample diameter, mm.
During torsion, all cross sections of the sample shift (rotate) around a common axis with respect to the fixed section. This shift increases with increasing distance from the place of fastening, and lines parallel to the axis of the sample become helical.
Based on the results of testing samples for torsion, the following characteristics are determined:
Shear modulus G , MPa (kgf/mm 2);
Torsional Yield Strength t 0.3, MPa (kgf/mm 2);
Conditional torsional strength t fc, MPa (kgf/mm 2);
True torsional strength t to, MPa (kgf/mm 2);
Maximum torsional residual shear gmax, glad;
The nature of failure during torsion: shear or tear.
Shear modulus is the ratio of shear stress to the conditional deformation caused by it.
Torsional yield strength is the shear stress at which the sample experiences a permanent shear of 0.3%.
Conditional ultimate torsional strength is a tangential stress equal to the ratio of the maximum torsional moment preceding failure to the polar moment of resistance of the sample cross-section.
True torsional strength is the highest true shear stress at failure of the specimen.
Maximum torsional permanent shear is the maximum angular deformation at a point on the surface of the sample at the moment of failure.
The nature of failure in torsion: shear - failure from tangential stresses, separation - failure from tensile stresses.
For torsion testing, a testing machine can be used that provides:
Free torsion of samples;
Smoothness of static loading;
Free movement of one of the grips along the axis of the sample;
Load measurement using a force meter;
Measuring the twist angle.
Requirements for testing equipment, samples, preparation and testing of metals at room temperature are given in GOST 3565-80.
For torsion tests, cylindrical samples with a working part diameter of 10 mm and a working part length of 50 and 100 mm with heads at the ends are used for fastening in the grips of the testing machine. Testing of samples and products proportional to standard ones, as well as tubular samples, is allowed. The shape and dimensions of the sample heads depend on the method of fastening the samples in the grips of the testing machine.
To test torsion of metals at low and high temperatures, special devices are used that allow heating or cooling of samples. When heating samples, it is necessary to hold them at the test temperature to ensure the stability of the structure.
24.12. Hardness measurement
Hardness determination is one of the most commonly used methods of mechanical testing of metals, since they are relatively simple and labor-intensive. Most methods are based on pressing an indenter into the metal being tested, and the resulting plastic or elastic deformation is considered as a measure of the hardness of the metal. Methods for determining hardness widely used in practice differ in the type of loading (static and dynamic) and the shape of the indenter pressed into the metal.
Hardness measurement under static loading
These methods differ in the shape of the indenter (ball, pyramid), its material (high-strength steels, hard alloys, diamond) and the magnitude of the applied load.
With a large indentation size (hardness determination according to Brinell, Rockwell, Vickers), average hardness values are obtained for macrovolumes of metal. With small print sizes commensurate with the structural components (microhardness measurement method), the hardness of individual structural components is revealed.