GB/T 8363-2018 Steel - Drop-weight tear tests method
1 Scope
This standard specifies the test principle, terms and definitions, symbols and explanations, specimens, test equipment and instruments, test procedures, uncertainty of test results, and test report for the drop-weight tear test (DWTT) method for steels.
This standard is applicable to the drop-weight tear test and result assessment of steel plates and pipes with a thickness ranging from 3 mm to 40 mm.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 2975 Steel and steel products - Location and preparation of samples and test pieces for mechanical testing
3 Test principle
A specimen in a simply supported beam state is fractured in one impact by a drop-weight or pendulum hammer released from a specified height, so as to test the drop-weight tear performances of steels, such as the percent shear area of the fracture surface, total absorbed energy and crack initiation energy.
4 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
4.1
drop-weight tear test; DWTT
test in which a specimen in a simply supported beam state is fractured in one impact by a drop-weight or pendulum hammer released from a specified height, followed by assessment of relevant performance results
4.2
diameter-to-thickness ratio
ratio of steel pipe diameter D to wall thickness t, abbreviated as D/t
4.3
ductile fracture surfaces
shear-fracture surfaces
dark gray, fibrous fracture zone on the fracture surface of the specimen fractured in accordance with this method
4.4
brittle fracture surfaces
cleavage-fracture surfaces
bright, crystalline fracture zone on the fracture surface of the specimen fractured in accordance with this method
4.5
percent shear area of the fracture surface
ratio of the area of the ductile fracture surfaces measured in accordance with this method to the area of the evaluation zone (the definition of the evaluation zone area is specified in 9.2) for assessment, expressed as a percentage and denoted as SA%
4.6
pressed notch
single-sided V-shaped notch pressed on the specimen with a special indenter
4.7
chevron notch
single-sided chevron notch machined on the specimen
4.8
total absorbed energy
Et
total energy consumed to fracture the DWTT specimen
4.9
crack initiation energy
Ei
energy consumed during crack initiation of the DWTT specimen
Note: Normally, the point of maximum force on the force-displacement curve is taken as the nominal crack initiation point.
4.10
crack propagation energy
Ep
energy consumed during the process from crack initiation to complete fracture of the DWTT specimen
5 Symbols and explanations
The symbols used in this standard and their corresponding explanations are specified in Table 1.
Contents
Foreword i
1 Scope
2 Normative references
3 Test principle
4 Terms and definitions
5 Symbols and explanations
6 Specimen
7 Test equipment and instruments
8 Test procedures
9 Test result assessment
10 Uncertainty of test results
11 Test report
Annex A (Normative) Treatment of brittle fracture surfaces on the fracture separation surfaces of controlled-rolled pipeline steel and assessment of abnormal fractures
Annex B (Informative) Instrumented system (oscillographic system) for DWTT test
Bibliography
GB/T 8363-2018 Steel - Drop-weight tear tests method
1 Scope
This standard specifies the test principle, terms and definitions, symbols and explanations, specimens, test equipment and instruments, test procedures, uncertainty of test results, and test report for the drop-weight tear test (DWTT) method for steels.
This standard is applicable to the drop-weight tear test and result assessment of steel plates and pipes with a thickness ranging from 3 mm to 40 mm.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 2975 Steel and steel products - Location and preparation of samples and test pieces for mechanical testing
3 Test principle
A specimen in a simply supported beam state is fractured in one impact by a drop-weight or pendulum hammer released from a specified height, so as to test the drop-weight tear performances of steels, such as the percent shear area of the fracture surface, total absorbed energy and crack initiation energy.
4 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
4.1
drop-weight tear test; DWTT
test in which a specimen in a simply supported beam state is fractured in one impact by a drop-weight or pendulum hammer released from a specified height, followed by assessment of relevant performance results
4.2
diameter-to-thickness ratio
ratio of steel pipe diameter D to wall thickness t, abbreviated as D/t
4.3
ductile fracture surfaces
shear-fracture surfaces
dark gray, fibrous fracture zone on the fracture surface of the specimen fractured in accordance with this method
4.4
brittle fracture surfaces
cleavage-fracture surfaces
bright, crystalline fracture zone on the fracture surface of the specimen fractured in accordance with this method
4.5
percent shear area of the fracture surface
ratio of the area of the ductile fracture surfaces measured in accordance with this method to the area of the evaluation zone (the definition of the evaluation zone area is specified in 9.2) for assessment, expressed as a percentage and denoted as SA%
4.6
pressed notch
single-sided V-shaped notch pressed on the specimen with a special indenter
4.7
chevron notch
single-sided chevron notch machined on the specimen
4.8
total absorbed energy
Et
total energy consumed to fracture the DWTT specimen
4.9
crack initiation energy
Ei
energy consumed during crack initiation of the DWTT specimen
Note: Normally, the point of maximum force on the force-displacement curve is taken as the nominal crack initiation point.
4.10
crack propagation energy
Ep
energy consumed during the process from crack initiation to complete fracture of the DWTT specimen
5 Symbols and explanations
The symbols used in this standard and their corresponding explanations are specified in Table 1.
Contents of GB/T 8363-2018
Contents
Foreword i
1 Scope
2 Normative references
3 Test principle
4 Terms and definitions
5 Symbols and explanations
6 Specimen
7 Test equipment and instruments
8 Test procedures
9 Test result assessment
10 Uncertainty of test results
11 Test report
Annex A (Normative) Treatment of brittle fracture surfaces on the fracture separation surfaces of controlled-rolled pipeline steel and assessment of abnormal fractures
Annex B (Informative) Instrumented system (oscillographic system) for DWTT test
Bibliography
