This standard specifies the principle, method, comparison specimen, equipment, conditions, steps, result evaluation and report of ultrasonic flaw detection of seamless steel tubes. This standard is applicable to ultrasonic testing of longitudinal and transverse defects of seamless steel tubes for various purposes. The flaw detection method described in this standard is mainly used to detect defects that destroy the metal continuity of steel tubes, but cannot effectively detect layered defects. This standard is applicable to steel tubes with an outer diameter equal to or greater than 6mm and a ratio of wall thickness to outer diameter not greater than 0.2. GB/T 5777-1996 Ultrasonic flaw detection test method for seamless steel tubes GB/T5777-1996 Standard download decompression password: www.bzxz.net

GB/T5777-1996
This standard is equivalent to ISO9303:1989 (E) of the International Organization for Standardization "Full-circumferential ultrasonic testing of longitudinal defects in seamless and welded (except submerged arc welded) steel pipes for pressure purposes", and amends GB4163-84 "Ultrasonic testing method for stainless steel pipes" and GB5777-86 "Ultrasonic testing method for seamless steel pipes" and merges the two. The main contents of the revision are as follows: 1. If there is no special agreement between the supply and demand parties, steel pipes for various purposes are changed to bidirectional detection, so as to more effectively ensure the physical quality of steel pipes after flaw detection.
2. The division of artificial defect levels on the comparison specimen is the same as ISO9303. Compared with GB4163, the original third level of 7% is changed to 8%, and the original fifth level of 15% is changed to 12.5%. Compared with GB5777, a highest level of 3% is added, a lowest level of 15% is reduced, and the original fourth level of 12% is changed to 12.5%.
3. Compared with ISO9303, the technical content adds the new electromagnetic acoustic detection technology with great promotion prospects and the test requirements for the comprehensive performance of the flaw detection equipment.
This standard can be used for ultrasonic flaw detection of seamless steel pipes for various purposes. This standard has been implemented since March 1, 1997, and replaces GB4163-84 and GB5777-86. Appendix A of this standard is the appendix of the standard.
This standard is proposed by the Ministry of Metallurgical Industry.
This standard is under the jurisdiction of the National Steel Standardization Technical Committee. This standard was drafted by the Special Steel Company of Shougang Corporation and Shanghai No. 5 Steel Plant. The main drafters of this standard are: Yang Xuezhi, Liu Dingzhu, Chen Yan, Wang Huaixiang, Ni Xiumei. This standard was first issued in January 1986.
GB/T5777-7996
International Standard Foreword
ISO (International Organization for Standardization) is a world-wide alliance of national standard groups (ISO member bodies). The preparation of international standards is usually carried out from beginning to end by ISO professional committees. Each member body has a subject of interest in which the professional committee belongs and an appropriate organization is established in that committee. International organizations, governmental and non-governmental, and liaisons in ISO, also participate in the work. ISO cooperates with the International Electrotechnical Commission (IEC) to carefully study all issues of electrotechnical standardization. Draft international standards, like international standards, are approved by the member bodies of the professional committee before they are formally adopted at an ISO meeting. Their approval is in accordance with ISO procedures requiring at least 75% approval by the member bodies voting. International Standard ISO9303 was approved by ISO/TC17 Steel Professional Committee. The method in Annex A is a non-essential part of this international standard. 32
1 Scope
National Standard of the People's Republic of China
Methods for ultrasonic flaw detection of seamless steel pipe
Seamless steel pipe and tubing.--Methods for ultrasonic testingGB/T 5777-1996
(eqvISo9303-1989)
Replaces GB4163--84
GB5777--86
This standard specifies the principle, method, comparison specimen, equipment, conditions, steps, result evaluation and report of ultrasonic flaw detection of seamless steel pipe. This standard is applicable to ultrasonic testing of longitudinal and transverse defects of seamless steel pipes for various purposes. The flaw detection method described in this standard is mainly used to detect defects that destroy the metal continuity of steel pipes, but cannot effectively detect laminar defects. This standard is applicable to steel pipes with an outer diameter equal to or greater than 6mm and a ratio of wall thickness to outer diameter not greater than 0.2. The inspection of steel pipes with a wall thickness to outer diameter ratio greater than 0.2 shall be subject to special methods agreed upon by both the supplier and the buyer in accordance with Appendix A of this standard. 2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and the parties using this standard should explore the possibility of using the latest versions of the following standards. YB4082-92 Comprehensive performance test method for automatic ultrasonic flaw detection system for steel pipes ZBY230--84A general technical conditions for pulse reflection ultrasonic flaw detector 3 Detection principle
The fact that ultrasonic probes can realize the mutual conversion between electrical energy and acoustic energy and the physical properties of ultrasonic waves when propagating in elastic media are the basis of the principle of ultrasonic flaw detection of steel pipes. When the ultrasonic beam emitted in a direction encounters a defect in the pipe, it will produce both wave reflection and wave attenuation. After signal processing by the flaw detector, if the reflection method is used for flaw detection, the defect echo signal can be obtained, and if the penetration method is used for flaw detection, the defect signal can be obtained by relying on the attenuation degree of the transmitted wave. Both instruments can give quantitative defect indications. Different types of ultrasonic waves can be excited in the tube by using the piezoelectric effect or the principle of electromagnetic induction. Therefore, both piezoelectric ultrasound and electromagnetic ultrasound can be used for ultrasonic testing of pipes. However, electromagnetic ultrasound is only applicable to ferromagnetic materials. 4 Flaw detection methods
4.1 Automatic inspection is carried out by using the transverse wave (or plate wave) reflection method (or penetration method) when the probe and the steel pipe are moving relative to each other. Only special large-diameter steel pipes can be inspected manually. When inspecting automatically or manually, the sound beam should be ensured to scan the entire surface of the pipe. Note: The two ends of the steel pipe cannot be effectively inspected during automatic inspection, but this area should be controlled within 200mm. 4.2 When inspecting longitudinal defects, the sound beam propagates in the circumferential direction of the pipe wall; when inspecting transverse defects, the sound beam propagates in the pipe wall along the pipe axis direction. The inspection of longitudinal and transverse defects should be carried out in two opposite directions of the pipe. 4.3 When the purchaser does not propose to inspect transverse defects, the supplier only inspects longitudinal defects. With the agreement between the supplier and the buyer, the inspection of longitudinal and transverse defects can be carried out in only one direction of the pipe. 4.4 When conducting automatic or manual inspection, a coupling medium with good coupling effect and no damage to the surface of the steel pipe should be selected. Approved by the State Administration of Technical Supervision on September 27, 1996 and implemented on March 7, 1997
5 Comparison Sample
5.1 Purpose
GB/T5777—1996
Comparison samples are used for the commissioning of flaw detection equipment, comprehensive performance testing and regular calibration during use. The artificial defects on the comparison sample are the basis for evaluating the equivalent of natural defects, but it should not be understood that the sizes of the detected natural defects and artificial defects are necessarily equal when the signal amplitudes are equal.
5.2 Materials
The steel pipe used to make the comparison sample and the steel pipe to be inspected should have the same nominal size and similar chemical composition, surface condition, heat treatment state and acoustic properties.
The steel pipe used to make the comparison sample shall not have natural defects that affect the comprehensive performance test of the flaw detection equipment. 5.3 Length
The length of the comparison sample shall meet the requirements of the flaw detection method and the flaw detection equipment. 5.4 Artificial defects
5.4.1 Shape
The artificial defects used to inspect longitudinal defects and transverse defects shall be longitudinal notches parallel to the pipe axis and transverse notches perpendicular to the pipe axis, respectively, and their cross-sectional shapes may be rectangular or V-shaped (see Figures 1 and 2). The two sides of the rectangular notch shall be parallel to each other and perpendicular to the bottom surface of the notch. When the electro-etching method is used, the bottom surface of the notch and the bottom corners are allowed to be slightly rounded. The angle of the V-shaped groove shall be 60°. V-shaped notch α=60°
Rectangular notch
5.4.2 Position
GB/T5777-1996
The longitudinal groove should be processed one on each of the inner and outer surfaces at the middle outer surface of the specimen and at both ends not more than 200mm from the end (excluding the length of the notch itself), and the nominal size of the three notches is the same. For stainless steel pipes for aviation and other important purposes, when the inner diameter is less than 12mm, the inner wall longitudinal groove can be omitted. For other steel pipes other than this, when the inner diameter is less than 25mm, the inner wall longitudinal groove can be omitted. The transverse groove should be processed one on each of the outer surfaces at the middle outer surface of the specimen and at both ends not more than 200mm from the end (excluding the width of the notch itself), and the nominal size of the three notches is the same. Under normal circumstances, the inner wall transverse groove is not processed, and special needs should be agreed upon by the supply and demand parties. 5.4.3 Size
The size of artificial defects is divided into five levels according to Table 1. The specific levels shall be implemented in accordance with the relevant steel pipe product standards. If the product standard does not specify, it shall be agreed upon by both parties or implemented according to the applicable scope recommended in Table 1. Note
1h in the table represents the depth of artificial defects and represents the nominal wall thickness of the steel pipe. 2The maximum depth of each level is 1.5mm. When the wall thickness is greater than 50mm, the maximum depth can be increased to 3.0mm5.4 with the agreement of both parties.4 Production and measurement
Artificial defects can be processed by electro-etching, mechanical or other methods. The depth of artificial defects can be measured by optical methods, conformation methods or other methods.
The comparison sample should be clearly marked. The measurement report of artificial defects should be issued by the metrology department of the second-level or above metrology unit. 6 Flaw detection equipment
Flaw detection equipment consists of flaw detector, probe, detection device, transmission device, sorting device and other auxiliary devices. Electromagnetic ultrasonic flaw detection equipment should be equipped with a demagnetization device.
6.1 Flaw detector
GB/T5777--1996
6.1.1 The flaw detector should be a pulse reflection multi-channel or single-channel ultrasonic flaw detector, and its attenuator (gain) accuracy, vertical linearity and dynamic range must be verified by the relevant departments and comply with the provisions of ZBY230-923.2. 6.1.2 The adjustable range of the repetition frequency of the flaw detector should meet the requirements of the flaw detection process. Table 1 Artificial defect size
·Maximum
6.1.3 The flaw detector should have an automatic alarm function. 6.2 Probe
Specified value
Allowable tolerance
Recommended application range
Aviation stainless steel pipe
Cold processed high pressure boiler steel pipe and other stainless steel pipesOther stainless steel pipes
Hot processed high pressure boiler steel pipe
Steel pipes for other purposes
6.2.1 The working frequency of the probe can be selected between 2.5MHz and 10MHz. The chip length or diameter of a single probe should not exceed 25mm, but when the length of the artificial defect is less than 20mm, it should not exceed 12mm. 6.2.2 Piezoelectric ultrasonic flaw detection can use line focusing or point focusing probes. Electromagnetic ultrasonic flaw detection must use a probe corresponding to the surface curvature of the steel pipe.
6.3 Detection device
The detection device should have a high-precision adjustment mechanism for the position of the probe relative to the steel pipe and can be reliably locked or can achieve good mechanical tracking to ensure that the incident conditions of the sound beam on the pipe remain unchanged under dynamic conditions. The area of ​​the pipe end that cannot be effectively detected due to the structure of the device should not exceed 200mm.
6.4 Transmission device
The transmission device should allow the steel pipe to pass through the detection device at a uniform speed and ensure that the steel pipe and the detection device have good concentricity during the inspection.
6.5 Sorting device
The sorting device should be able to reliably separate the pipes that pass the flaw detection from the pipes that fail the flaw detection. 7 Flaw detection conditions
7.1 Ultrasonic flaw detection of steel pipes is usually carried out after all the production processes of the pipes are completed. The inner and outer surfaces of the inspected steel pipes should be smooth and clean, the ends should be free of burrs and have good straightness to ensure the reliability of the inspection results. 7.2 The flaw detection equipment shall be operated by personnel holding a technical qualification certificate of ultrasonic flaw detection level I or above recognized by the authority and technical guarantee shall be provided by professional management personnel.
8 Flaw detection steps
8.1 Equipment debugging
8.1.1 Each time the flaw detection equipment is reused or the inspection specifications are changed, the flaw detection equipment shall be debugged using the comparison sample specified in this standard. 8.1.2 After the equipment is debugged, the signal amplitude of the same artificial defect on the comparison sample at different positions in the circumferential direction shall be close to the same. 8.1.3 When the inner and outer wall artificial defect signals use the same alarm gate, the alarm sensitivity of the flaw detector shall be set according to the lower amplitude signal of the inner and outer wall signals and the signals at different circumferential positions. When the inner and outer wall artificial defect signals use two different alarm gates, the alarm sensitivity of the flaw detector shall be set according to the lower amplitude signal of the inner and outer wall artificial defects at different circumferential positions. At the same time, the width of the two gates should meet the alarm requirements of defect signals at various parts of the pipe wall. 8.2 Equipment testing
8.2.1 After the equipment is debugged, the circumferential sensitivity difference and the inner and outer wall sensitivity difference of the flaw detection equipment should be tested in accordance with YB4082. The test results should comply with the provisions of this standard.
8.2.2 The operating speed of the equipment during the test should be the same as the operating speed of the normal inspection. For multi-channel flaw detection equipment, if each channel is tested separately, the test speed can be equal to the ratio of the normal inspection speed to the number of channels of the equipment. 8.3 Flaw detection inspection
8.3.1 Flaw detection inspection can be carried out only after the equipment test results meet 8.2.1 of this standard. Flaw detection inspection should be carried out batch by batch. 8.3.2 During the inspection process, the flaw detection personnel must take reliable monitoring measures for the defect indication signal to prevent defects from being missed. 8.4 Equipment calibration
8.4.1 During the continuous inspection of steel pipes of the same specification, the flaw detection equipment should be regularly calibrated using comparative samples, and the calibration time interval should not exceed 4h. The verification content is the same as the equipment test items, but multi-channel equipment can sample individual channels, and the remaining channels are required to have good repeatability in detecting artificial defects.
The equipment should also be verified at the beginning and end of the continuous inspection of steel pipes of the same specification and when the equipment operator is replaced during the continuous inspection.
8.4.2 If the verification result does not meet the requirements, the equipment should be re-debugged and tested. After meeting the requirements, the pipes inspected after the last verification should be re-inspected.
9 Result evaluation
9.1 If the entire steel pipe does not produce defect signals or the signal amplitude is lower than the preset alarm level after inspection, it is considered that this inspection is qualified. 9.2 If the entire steel pipe produces a signal equal to or greater than the preset alarm level after inspection, the steel pipe is considered suspicious. 9.3 Any of the following methods can be used to deal with suspicious steel pipes; a) Repeated flaw detection inspection according to the method specified in this standard. If no defect signals are generated or the signal amplitude is lower than the preset alarm level, it is considered that this inspection is qualified.
b) After removing the visible defects of the suspected parts, if the size of the steel pipe is within the allowable tolerance range, the pipe shall be re-inspected according to the method specified in this standard. If no defect signal is generated or the signal amplitude is lower than the preset alarm level, it is considered that this inspection is qualified. c) Other non-destructive inspections are carried out on the suspected parts according to the methods and acceptance standards agreed upon by the supplier and the buyer. d) All suspected parts are removed.
e) The suspected steel pipe is evaluated as unqualified for this inspection. 10 Flaw Detection Report
After the flaw detection of the steel pipe, a flaw detection report issued by a person holding a technical qualification certificate of ultrasonic flaw detection level II or above recognized by an authoritative department shall be provided to the relevant departments and the buyer (when the buyer needs it). The flaw detection report shall include the following contents: a) furnace batch number, steel grade, specification, number of flaws detected; b) product standard number, this standard number, shape and level of artificial defects of comparison sample; c) flaw detector model, probe type and specification, flaw detection method; d) flaw detection results, flaw detection date, date of report issuance; e) name of operator and signatory and their technical qualification level. 37
GB/T 5777---1996
Appendix A
(Appendix of the standard)
Inspection of steel pipes with a wall thickness to outer diameter ratio greater than 0.2 When the wall thickness to outer diameter ratio of the steel pipe is greater than 0.2, a special inspection method shall be agreed upon by the supplier and buyer in accordance with Article A1 or Article A2. When the wall thickness to outer diameter ratio of the pipe is greater than 0.2 and less than or equal to 0.25, the depth of artificial defects on the inner wall shall be greater than the depth of artificial defects on the outer wall according to the value A1
listed in Table A1.
Wall thickness/outer diameter
0. 201~0. 210
0. 211 ~0. 222
0.223~~0.235
0. 236~0. 250
Inner wall artificial defect depth/outer wall artificial defect depth1.0
A2When the ratio of the wall thickness to the outer diameter of the pipe is greater than 0.2 and less than 0.3, the outer wall defects can be inspected by the refracted longitudinal wave in the pipe, and the inner wall defects can be inspected by the reflected transverse wave after the wave mode conversion (see Figure A1). When this inspection method is used, the ratio of the inner wall artificial defect depth to the outer wall artificial defect depth should be agreed upon by the supply and demand parties, but it should not exceed the numerical range listed in Table A1. TR
TR: Self-transmitting and self-receiving probe or dual-chip separated probe I; Longitudinal wave
S: Shear wave
Test method for converting longitudinal wave into shear wave2 Probe
Specified value
Allowable tolerance
Recommended application range
Aviation stainless steel pipe
Cold processed high pressure boiler steel pipe and other stainless steel pipesOther stainless steel pipes
Hot processed high pressure boiler steel pipe
Steel pipes for other purposes
6.2.1 The working frequency of the probe can be selected between 2.5MHz and 10MHz. The length or diameter of the chip of a single probe should not exceed 25mm, but when the length of the artificial defect is less than 20mm, it should not exceed 12mm. 6.2.2 Line focusing or point focusing probes can be used for piezoelectric ultrasonic testing. Electromagnetic ultrasonic testing must use a probe corresponding to the curvature of the steel pipe surface.
6.3 Testing device
The testing device should have a high-precision adjustment mechanism for the position of the probe relative to the steel pipe and can be reliably locked or can achieve good mechanical tracking to ensure that the incident conditions of the sound beam on the pipe remain unchanged under dynamic conditions. The area of ​​the pipe end that cannot be effectively detected due to the structure of the device should not be greater than 200mm.
6.4 Transmission device
The transmission device should allow the steel pipe to pass through the detection device at a uniform speed and ensure that the steel pipe and the detection device have good concentricity during the inspection.
6.5 Sorting device
The sorting device should be able to reliably separate the pipes that pass the flaw detection from the pipes that fail the flaw detection. 7 Flaw detection conditions
7.1 Ultrasonic flaw detection of steel pipes is usually carried out after all the production processes of the pipes are completed. The inner and outer surfaces of the inspected steel pipes should be smooth and clean, with no burrs on the ends and good straightness to ensure the reliability of the inspection results. 7.2 The flaw detection equipment should be operated by personnel holding a technical qualification certificate of ultrasonic flaw detection level I or above recognized by an authoritative department and provided with technical guarantees by professional management personnel.
8 Flaw detection steps
8.1 Equipment debugging
8.1.1 Each time the flaw detection equipment is reused or the inspection specifications are changed, the flaw detection equipment must be debugged using the comparison sample specified in this standard. 8.1.2 After the equipment is debugged, the signal amplitude of the same artificial defect on the comparison sample at different positions in the circumferential direction should be close to the same. 8.1.3 When the inner and outer wall artificial defect signals use the same alarm gate, the alarm sensitivity of the flaw detector should be set according to the lower amplitude signal of the inner and outer wall signals and the signals at different circumferential positions. When the inner and outer wall artificial defect signals use two different alarm gates, the alarm sensitivity of the flaw detector should be set according to the lower amplitude signal of the inner and outer wall artificial defects at different circumferential positions. At the same time, the width of the two gates should meet the alarm requirements of the defect signals at various parts of the pipe wall. 8.2 Equipment testing
8.2.1 After the equipment is debugged, the circumferential sensitivity difference and the inner and outer wall sensitivity difference of the flaw detection equipment should be tested in accordance with YB4082. The test results should comply with the provisions of this standard.
8.2.2 The operating speed of the equipment during testing should be the same as the operating speed of normal inspection. If each channel of the multi-channel flaw detection equipment is tested separately, the test speed can be equal to the ratio of the normal inspection speed to the number of channels of the equipment. 8.3 Flaw detection inspection
8.3.1 Flaw detection inspection can only be carried out after the equipment test results comply with 8.2.1 of this standard. Flaw detection inspection should be carried out batch by batch. 8.3.2 During the inspection process, the flaw detection personnel must take reliable monitoring measures for the defect indication signal to prevent defects from being missed. 8.4 Equipment calibration
8.4.1 During the continuous inspection of steel pipes of the same specification, the flaw detection equipment should be calibrated regularly using comparison samples, and the calibration time interval should not exceed 4h. The verification content is the same as the equipment test items, but multi-channel equipment can sample individual channels, and the remaining channels are required to have good repeatability in detecting artificial defects.
The equipment should also be verified at the beginning and end of the continuous inspection of steel pipes of the same specification and when the equipment operator is replaced during the continuous inspection.
8.4.2 If the verification result does not meet the requirements, the equipment should be re-debugged and tested. After meeting the requirements, the pipes inspected after the last verification should be re-inspected.
9 Result evaluation
9.1 If the entire steel pipe does not produce defect signals or the signal amplitude is lower than the preset alarm level after inspection, it is considered that this inspection is qualified. 9.2 If the entire steel pipe produces a signal equal to or greater than the preset alarm level after inspection, the steel pipe is considered suspicious. 9.3 Any of the following methods can be used to deal with suspicious steel pipes; a) Repeated flaw detection inspection according to the method specified in this standard. If no defect signals are generated or the signal amplitude is lower than the preset alarm level, it is considered that this inspection is qualified.
b) After removing the visible defects of the suspected parts, if the size of the steel pipe is within the allowable tolerance range, the pipe shall be re-inspected according to the method specified in this standard. If no defect signal is generated or the signal amplitude is lower than the preset alarm level, it is considered that this inspection is qualified. c) Other non-destructive inspections are carried out on the suspected parts according to the methods and acceptance standards agreed upon by the supplier and the buyer. d) All suspected parts are removed.
e) The suspected steel pipe is evaluated as unqualified for this inspection. 10 Flaw Detection Report
After the flaw detection of the steel pipe, a flaw detection report issued by a person holding a technical qualification certificate of ultrasonic flaw detection level II or above recognized by an authoritative department shall be provided to the relevant departments and the buyer (when the buyer needs it). The flaw detection report shall include the following contents: a) furnace batch number, steel grade, specification, number of flaws detected; b) product standard number, this standard number, shape and level of artificial defects of comparison sample; c) flaw detector model, probe type and specification, flaw detection method; d) flaw detection results, flaw detection date, date of report issuance; e) name of operator and signatory and their technical qualification level. 37
GB/T 5777---1996
Appendix A
(Appendix of the standard)
Inspection of steel pipes with a wall thickness to outer diameter ratio greater than 0.2 When the wall thickness to outer diameter ratio of the steel pipe is greater than 0.2, a special inspection method shall be agreed upon by the supplier and buyer in accordance with Article A1 or Article A2. When the wall thickness to outer diameter ratio of the pipe is greater than 0.2 and less than or equal to 0.25, the depth of artificial defects on the inner wall shall be greater than the depth of artificial defects on the outer wall according to the value A1
listed in Table A1.
Wall thickness/outer diameter
0. 201~0. 210
0. 211 ~0. 222
0.223~~0.235
0. 236~0. 250
Inner wall artificial defect depth/outer wall artificial defect depth1.0
A2When the ratio of the wall thickness to the outer diameter of the pipe is greater than 0.2 and less than 0.3, the outer wall defects can be inspected by the refracted longitudinal wave in the pipe, and the inner wall defects can be inspected by the reflected transverse wave after the wave mode conversion (see Figure A1). When this inspection method is used, the ratio of the inner wall artificial defect depth to the outer wall artificial defect depth should be agreed upon by the supply and demand parties, but it should not exceed the numerical range listed in Table A1. TR
TR: Self-transmitting and self-receiving probe or dual-chip separated probe I; Longitudinal wave
S: Shear wave
Test method for converting longitudinal wave into shear wave2 Probe
Specified value
Allowable tolerance
Recommended application range
Aviation stainless steel pipe
Cold processed high pressure boiler steel pipe and other stainless steel pipesOther stainless steel pipes
Hot processed high pressure boiler steel pipe
Steel pipes for other purposes
6.2.1 The working frequency of the probe can be selected between 2.5MHz and 10MHz. The length or diameter of the chip of a single probe should not exceed 25mm, but when the length of the artificial defect is less than 20mm, it should not exceed 12mm. 6.2.2 Line focusing or point focusing probes can be used for piezoelectric ultrasonic testing. Electromagnetic ultrasonic testing must use a probe corresponding to the curvature of the steel pipe surface.
6.3 Testing device
The testing device should have a high-precision adjustment mechanism for the position of the probe relative to the steel pipe and can be reliably locked or can achieve good mechanical tracking to ensure that the incident conditions of the sound beam on the pipe remain unchanged under dynamic conditions. The area of ​​the pipe end that cannot be effectively detected due to the structure of the device should not be greater than 200mm.
6.4 Transmission device
The transmission device should allow the steel pipe to pass through the detection device at a uniform speed and ensure that the steel pipe and the detection device have good concentricity during the inspection.
6.5 Sorting device
The sorting device should be able to reliably separate the pipes that pass the flaw detection from the pipes that fail the flaw detection. 7 Flaw detection conditions
7.1 Ultrasonic flaw detection of steel pipes is usually carried out after all the production processes of the pipes are completed. The inner and outer surfaces of the inspected steel pipes should be smooth and clean, with no burrs on the ends and good straightness to ensure the reliability of the inspection results. 7.2 The flaw detection equipment should be operated by personnel holding a technical qualification certificate of ultrasonic flaw detection level I or above recognized by an authoritative department and provided with technical guarantees by professional management personnel.
8 Flaw detection steps
8.1 Equipment debugging
8.1.1 Each time the flaw detection equipment is reused or the inspection specifications are changed, the flaw detection equipment must be debugged using the comparison sample specified in this standard. 8.1.2 After the equipment is debugged, the signal amplitude of the same artificial defect on the comparison sample at different positions in the circumferential direction should be close to the same. 8.1.3 When the inner and outer wall artificial defect signals use the same alarm gate, the alarm sensitivity of the flaw detector should be set according to the lower amplitude signal of the inner and outer wall signals and the signals at different circumferential positions. When the inner and outer wall artificial defect signals use two different alarm gates, the alarm sensitivity of the flaw detector should be set according to the lower amplitude signal of the inner and outer wall artificial defects at different circumferential positions. At the same time, the width of the two gates should meet the alarm requirements of the defect signals at various parts of the pipe wall. 8.2 Equipment testing
8.2.1 After the equipment is debugged, the circumferential sensitivity difference and the inner and outer wall sensitivity difference of the flaw detection equipment should be tested in accordance with YB4082. The test results should comply with the provisions of this standard.
8.2.2 The operating speed of the equipment during testing should be the same as the operating speed of normal inspection. If each channel of the multi-channel flaw detection equipment is tested separately, the test speed can be equal to the ratio of the normal inspection speed to the number of channels of the equipment. 8.3 Flaw detection inspection
8.3.1 Flaw detection inspection can only be carried out after the equipment test results comply with 8.2.1 of this standard. Flaw detection inspection should be carried out batch by batch. 8.3.2 During the inspection process, the flaw detection personnel must take reliable monitoring measures for the defect indication signal to prevent defects from being missed. 8.4 Equipment calibration
8.4.1 During the continuous inspection of steel pipes of the same specification, the flaw detection equipment should be calibrated regularly using comparison samples, and the calibration time interval should not exceed 4h. The verification content is the same as the equipment test items, but multi-channel equipment can sample individual channels, and the remaining channels are required to have good repeatability in detecting artificial defects.
The equipment should also be verified at the beginning and end of the continuous inspection of steel pipes of the same specification and when the equipment operator is replaced during the continuous inspection.
8.4.2 If the verification result does not meet the requirements, the equipment should be re-debugged and tested. After meeting the requirements, the pipes inspected after the last verification should be re-inspected.
9 Result evaluation
9.1 If the entire steel pipe does not produce defect signals or the signal amplitude is lower than the preset alarm level after inspection, it is considered that this inspection is qualified. 9.2 If the entire steel pipe produces a signal equal to or greater than the preset alarm level after inspection, the steel pipe is considered suspicious. 9.3 Any of the following methods can be used to deal with suspicious steel pipes; a) Repeated flaw detection inspection according to the method specified in this standard. If no defect signals are generated or the signal amplitude is lower than the preset alarm level, it is considered that this inspection is qualified.
b) After removing the visible defects of the suspected parts, if the size of the steel pipe is within the allowable tolerance range, the pipe shall be re-inspected according to the method specified in this standard. If no defect signal is generated or the signal amplitude is lower than the preset alarm level, it is considered that this inspection is qualified. c) Other non-destructive inspections are carried out on the suspected parts according to the methods and acceptance standards agreed upon by the supplier and the buyer. d) All suspected parts are removed.
e) The suspected steel pipe is evaluated as unqualified for this inspection. 10 Flaw Detection Report
After the flaw detection of the steel pipe, a flaw detection report issued by a person holding a technical qualification certificate of ultrasonic flaw detection level II or above recognized by an authoritative department shall be provided to the relevant departments and the buyer (when the buyer needs it). The flaw detection report shall include the following contents: a) furnace batch number, steel grade, specification, number of flaws detected; b) product standard number, this standard number, shape and level of artificial defects of comparison sample; c) flaw detector model, probe type and specification, flaw detection method; d) flaw detection results, flaw detection date, date of report issuance; e) name of operator and signatory and their technical qualification level. 37
GB/T 5777---1996
Appendix A
(Appendix of the standard)
Inspection of steel pipes with a wall thickness to outer diameter ratio greater than 0.2 When the wall thickness to outer diameter ratio of the steel pipe is greater than 0.2, a special inspection method shall be agreed upon by the supplier and buyer in accordance with Article A1 or Article A2. When the wall thickness to outer diameter ratio of the pipe is greater than 0.2 and less than or equal to 0.25, the depth of artificial defects on the inner wall shall be greater than the depth of artificial defects on the outer wall according to the value A1
listed in Table A1.
Wall thickness/outer diameter
0. 201~0. 210
0. 211 ~0. 222
0.223~~0.235
0. 236~0. 250
Inner wall artificial defect depth/outer wall artificial defect depth1.0
A2When the ratio of the wall thickness to the outer diameter of the pipe is greater than 0.2 and less than 0.3, the outer wall defects can be inspected by the refracted longitudinal wave in the pipe, and the inner wall defects can be inspected by the reflected transverse wave after the wave mode conversion (see Figure A1). When this inspection method is used, the ratio of the inner wall artificial defect depth to the outer wall artificial defect depth should be agreed upon by the supply and demand parties, but it should not exceed the numerical range listed in Table A1. TR
TR: Self-transmitting and self-receiving probe or dual-chip separated probe I; Longitudinal wave
S: Shear wave
Test method for converting longitudinal wave into shear wave1 Each time the flaw detection equipment is reused or the inspection specifications are changed, the flaw detection equipment must be debugged using the comparison sample specified in this standard. 8.1.2 After the equipment is debugged, the signal amplitude of the same artificial defect at different positions in the circumferential direction on the comparison sample should be close to the same. 8.1.3 When the inner and outer wall artificial defect signals use the same alarm gate, the alarm sensitivity of the flaw detector should be set according to the lower amplitude signal of the inner and outer wall signals and the signals at different circumferential positions. When the inner and outer wall artificial defect signals use two different alarm gates, the alarm sensitivity of the flaw detector should be set according to the lower amplitude signal of the inner and outer wall artificial defects at different circumferential positions. At the same time, the width of the two gates should meet the alarm requirements of the defect signals at various parts of the pipe wall. 8.2 Equipment testing
8.2.1 After the equipment is debugged, the circumferential sensitivity difference and the inner and outer wall sensitivity difference of the flaw detection equipment should be tested in accordance with YB4082. The test results should comply with the provisions of this standard.
8.2.2 The operating speed of the equipment during testing should be the same as the operating speed of normal inspection. If each channel of the multi-channel flaw detection equipment is tested separately, the test speed can be equal to the ratio of the normal inspection speed to the number of channels of the equipment. 8.3 Flaw detection inspection
8.3.1 Flaw detection inspection can only be carried out after the equipment test results comply with 8.2.1 of this standard. Flaw detection inspection should be carried out batch by batch. 8.3.2 During the inspection process, the flaw detection personnel must take reliable monitoring measures for the defect indication signal to prevent defects from being missed. 8.4 Equipment calibration
8.4.1 During the continuous inspection of steel pipes of the same specification, the flaw detection equipment should be calibrated regularly using comparison samples, and the calibration time interval should not exceed 4h. The verification content is the same as the equipment test items, but multi-channel equipment can sample individual channels, and the remaining channels are required to have good repeatability in detecting artificial defects.
The equipment should also be verified at the beginning and end of the continuous inspection of steel pipes of the same specification and when the equipment operator is replaced during the continuous inspection.
8.4.2 If the verification result does not meet the requirements, the equipment should be re-debugged and tested. After meeting the requirements, the pipes inspected after the last verification should be re-inspected.
9 Result evaluation
9.1 If the entire steel pipe does not produce defect signals or the signal amplitude is lower than the preset alarm level after inspection, it is considered that this inspection is qualified. 9.2 If the entire steel pipe produces a signal equal to or greater than the preset alarm level after inspection, the steel pipe is considered suspicious. 9.3 Any of the following methods can be used to deal with suspicious steel pipes; a) Repeated flaw detection inspection according to the method specified in this standard. If no defect signals are generated or the signal amplitude is lower than the preset alarm level, it is considered that this inspection is qualified.
b) After removing the visible defects of the suspected parts, if the size of the steel pipe is within the allowable tolerance range, the pipe shall be re-inspected according to the method specified in this standard. If no defect signal is generated or the signal amplitude is lower than the preset alarm level, it is considered that this inspection is qualified. c) Other non-destructive inspections are carried out on the suspected parts according to the methods and acceptance standards agreed upon by the supplier and the buyer. d) All suspected parts are removed.
e) The suspected steel pipe is evaluated as unqualified for this inspection. 10 Flaw Detection Report
After the flaw detection of the steel pipe, a flaw detection report issued by a person holding a technical qualification certificate of ultrasonic flaw detection level II or above recognized by an authoritative department shall be provided to the relevant departments and the buyer (when the buyer needs it). The flaw detection report shall include the following contents: a) furnace batch number, steel grade, specification, number of flaws detected; b) product standard number, this standard number, shape and level of artificial defects of comparison sample; c) flaw detector model, probe type and specification, flaw detection method; d) flaw detection results, flaw detection date, date of report issuance; e) name of operator and signatory and their technical qualification level. 37
GB/T 5777---1996
Appendix A
(Appendix of the standard)
Inspection of steel pipes with a wall thickness to outer diameter ratio greater than 0.2 When the wall thickness to outer diameter ratio of the steel pipe is greater than 0.2, a special inspection method shall be agreed upon by the supplier and buyer in accordance with Article A1 or Article A2. When the wall thickness to outer diameter ratio of the pipe is greater than 0.2 and less than or equal to 0.25, the depth of artificial defects on the inner wall shall be greater than the depth of artificial defects on the outer wall according to the value A1
listed in Table A1.
Wall thickness/outer diameter
0. 201~0. 210
0. 211 ~0. 222
0.223~~0.235
0. 236~0. 250
Inner wall artificial defect depth/outer wall artificial defect depth1.0
A2When the ratio of the wall thickness to the outer diameter of the pipe is greater than 0.2 and less than 0.3, the outer wall defects can be inspected by the refracted longitudinal wave in the pipe, and the inner wall defects can be inspected by the reflected transverse wave after the wave mode conversion (see Figure A1). When this inspection method is used, the ratio of the inner wall artificial defect depth to the outer wall artificial defect depth should be agreed upon by the supply and demand parties, but it should not exceed the numerical range listed in Table A1. TR
TR: Self-transmitting and self-receiving probe or dual-chip separated probe I; Longitudinal wave
S: Shear wave
Test method for converting longitudinal wave into shear wave1 Each time the flaw detection equipment is reused or the inspection specifications are changed, the flaw detection equipment must be debugged using the comparison sample specified in this standard. 8.1.2 After the equipment is debugged, the signal amplitude of the same artificial defect at different positions in the circumferential direction on the comparison sample should be close to the same. 8.1.3 When the inner and outer wall artificial defect signals use the same alarm gate, the alarm sensitivity of the flaw detector should be set according to the lower amplitude signal of the inner and outer wall signals and the signals at different circumferential positions. When the inner and outer wall artificial defect signals use two different alarm gates, the alarm sensitivity of the flaw detector should be set according to the lower amplitude signal of the inner and outer wall artificial defects at different circumferential positions. At the same time, the width of the two gates should meet the alarm requirements of the defect signals at various parts of the pipe wall. 8.2 Equipment testing
8.2.1 After the equipment is debugged, the circumferential sensitivity difference and the inner and outer wall sensitivity difference of the flaw detection equipment should be tested in accordance with YB4082. The test results should comply with the provisions of this standard.
8.2.2 The operating speed of the equipment during testing should be the same as the operating speed of normal inspection. If each channel of the multi-channel flaw detection equipment is tested separately, the test speed can be equal to the ratio of the normal inspection speed to the number of channels of the equipment. 8.3 Flaw detection inspection
8.3.1 Flaw detection inspection can only be carried out after the equipment test results comply with 8.2.1 of this standard. Flaw detection inspection should be carried out batch by batch. 8.3.2 During the inspection process, the flaw detection personnel must take reliable monitoring measures for the defect indication signal to prevent defects from being missed. 8.4 Equipment calibration
8.4.1 During the continuous inspection of steel pipes of the same specification, the flaw detection equipment should be calibrated regularly using comparison samples, and the calibration time interval should not exceed 4h. The verification content is the same as the equipment test items, but multi-channel equipment can sample individual channels, and the remaining channels are required to have good repeatability in detecting artificial defects.
The equipment should also be verified at the beginning and end of the continuous inspection of steel pipes of the same specification and when the equipment operator is replaced during the continuous inspection.
8.4.2 If the verification result does not meet the requirements, the equipment should be re-debugged and tested. After meeting the requirements, the pipes inspected after the last verification should be re-inspected.
9 Result evaluation
9.1 If the entire steel pipe does not produce defect signals or the signal amplitude is lower than the preset alarm level after inspection, it is considered that this inspection is qualified. 9.2 If the entire steel pipe produces a signal equal to or greater than the preset alarm level after inspection, the steel pipe is considered suspicious. 9.3 Any of the following methods can be used to deal with suspicious steel pipes; a) Repeated flaw detection inspection according to the method specified in this standard. If no defect signals are generated or the signal amplitude is lower than the preset alarm level, it is considered that this inspection is qualified.
b) After removing the visible defects of the suspected parts, if the size of the steel pipe is within the allowable tolerance range, the pipe shall be re-inspected according to the method specified in this standard. If no defect signal is generated or the signal amplitude is lower than the preset alarm level, it is considered that this inspection is qualified. c) Other non-destructive inspections are carried out on the suspected parts according to the methods and acceptance standards agreed upon by the supplier and the buyer. d) All suspected parts are removed.
e) The suspected steel pipe is evaluated as unqualified for this inspection. 10 Flaw Detection Report
After the flaw detection of the steel pipe, a flaw detection report issued by a person holding a technical qualification certificate of ultrasonic flaw detection level II or above recognized by an authoritative department shall be provided to the relevant departments and the buyer (when the buyer needs it). The flaw detection report shall include the following contents: a) furnace batch number, steel grade, specification, number of flaws detected; b) product standard number, this standard number, shape and level of artificial defects of comparison sample; c) flaw detector model, probe type and specification, flaw detection method; d) flaw detection results, flaw detection date, date of report issuance; e) name of operator and signatory and their technical qualification level. 37
GB/T 5777---1996
Appendix A
(Appendix of the standard)
Inspection of steel pipes with a wall thickness to outer diameter ratio greater than 0.2 When the wall thickness to outer diameter ratio of the steel pipe is greater than 0.2, a special inspection method shall be agreed upon by the supplier and buyer in accordance with Article A1 or Article A2. When the wall thickness to outer diameter ratio of the pipe is greater than 0.2 and less than or equal to 0.25, the depth of artificial defects on the inner wall shall be greater than the depth of artificial defects on the outer wall according to the value A1
listed in Table A1.
Wall thickness/outer diameter
0. 201~0. 210bZxz.net
0. 211 ~0. 222
0.223~~0.235
0. 236~0. 250
Inner wall artificial defect depth/outer wall artificial defect depth1.0
A2When the ratio of the wall thickness to the outer diameter of the pipe is greater than 0.2 and less than 0.3, the outer wall defects can be inspected by the refracted longitudinal wave in the pipe, and the inner wall defects can be inspected by the reflected transverse wave after the wave mode conversion (see Figure A1). When this inspection method is used, the ratio of the inner wall artificial defect depth to the outer wall artificial defect depth should be agreed upon by the supply and demand parties, but it should not exceed the numerical range listed in Table A1. TR
TR: Self-transmitting and self-receiving probe or dual-chip separated probe I; Longitudinal wave
S: Shear wave
Test method for converting longitudinal wave into shear wave3 Any of the following methods can be used to deal with suspicious steel pipes: a) Repeat the flaw detection test according to the method specified in this standard. If no defect signal is generated or the signal amplitude is lower than the preset alarm level, the test is considered to be qualified.
b) After removing the visible defects of the suspicious parts, if the size of the steel pipe is within the allowable tolerance range, the pipe should be re-tested according to the method specified in this standard. If no defect signal is generated or the signal amplitude is lower than the preset alarm level, the test is considered to be qualified. c) Other non-destructive tests are carried out on the suspicious parts according to the methods and acceptance standards agreed upon by the supply and demand parties. d) All suspicious parts are removed.
e) The suspicious steel pipe is evaluated as unqualified for this test. 10 Flaw Detection Report
After the flaw detection test of the steel pipe, a flaw detection report issued by a person holding a technical qualification certificate of ultrasonic flaw detection level II or above recognized by an authoritative department shall be provided to the relevant departments and the demander (when the demander needs it). The flaw detection report shall include the following contents: a) furnace batch number, steel grade, specification, number of flaws detected; b) product standard number, this standard number, shape and level of artificial defects of comparison sample; c) flaw detector model, probe type and specification, flaw detection method; d) flaw detection results, flaw detection date, date of report issuance; e) name of operator and signatory and their technical qualification level. 37
GB/T 5777---1996
Appendix A
(Appendix of the standard)
Inspection of steel pipes with a wall thickness to outer diameter ratio greater than 0.2 When the wall thickness to outer diameter ratio of the steel pipe is greater than 0.2, a special inspection method shall be agreed upon by the supplier and buyer in accordance with Article A1 or Article A2. When the wall thickness to outer diameter ratio of the pipe is greater than 0.2 and less than or equal to 0.25, the depth of artificial defects on the inner wall shall be greater than the depth of artificial defects on the outer wall according to the value A1
listed in Table A1.
Wall thickness/outer diameter
0. 201~0. 210
0. 211 ~0. 222
0.223~~0.235
0. 236~0. 250
Inner wall artificial defect depth/outer wall artificial defect depth1.0
A2When the ratio of the wall thickness to the outer diameter of the pipe is greater than 0.2 and less than 0.3, the outer wall defects can be inspected by the refracted longitudinal wave in the pipe, and the inner wall defects can be inspected by the reflected transverse wave after the wave mode conversion (see Figure A1). When this inspection method is used, the ratio of the inner wall artificial defect depth to the outer wall artificial defect depth should be agreed upon by the supply and demand parties, but it should not exceed the numerical range listed in Table A1. TR
TR: Self-transmitting and self-receiving probe or dual-chip separated probe I; Longitudinal wave
S: Shear wave
Test method for converting longitudinal wave into shear wave3 Any of the following methods can be used to deal with suspicious steel pipes: a) Repeat the flaw detection test according to the method specified in this standard. If no defect signal is generated or the signal amplitude is lower than the preset alarm level, the test is considered to be qualified.
b) After removing the visible defects of the suspicious parts, if the size of the steel pipe is within the allowable tolerance range, the pipe should be re-tested according to the method specified in this standard. If no defect signal is generated or the signal amplitude is lower than the preset alarm level, the test is considered to be qualified. c) Other non-destructive tests are carried out on the suspicious parts according to the methods and acceptance standards agreed upon by the supply and demand parties. d) All suspicious parts are removed.
e) The suspicious steel pipe is evaluated as unqualified for this test. 10 Flaw Detection Report
After the flaw detection test of the steel pipe, a flaw detection report issued by a person holding a technical qualification certificate of ultrasonic flaw detection level II or above recognized by an authoritative department shall be provided to the relevant departments and the demander (when the demander needs it). The flaw detection report shall include the following contents: a) furnace batch number, steel grade, specification, number of flaws detected; b) product standard number, this standard number, shape and level of artificial defects of comparison sample; c) flaw detector model, probe type and specification, flaw detection method; d) flaw detection results, flaw detection date, date of report issuance; e) name of operator and signatory and their technical qualification level. 37
GB/T 5777---1996
Appendix A
(Appendix of the standard)
Inspection of steel pipes with a wall thickness to outer diameter ratio greater than 0.2 When the wall thickness to outer diameter ratio of the steel pipe is greater than 0.2, a special inspection method shall be agreed upon by the supplier and buyer in accordance with Article A1 or Article A2. When the wall thickness to outer diameter ratio of the pipe is greater than 0.2 and less than or equal to 0.25, the depth of artificial defects on the inner wall shall be greater than the depth of artificial defects on the outer wall according to the value A1
listed in Table A1.
Wall thickness/outer diameter
0. 201~0. 210
0. 211 ~0. 222
0.223~~0.235
0. 236~0. 250
Inner wall artificial defect depth/outer wall artificial defect depth1.0
A2When the ratio of the wall thickness to the outer diameter of the pipe is greater than 0.2 and less than 0.3, the outer wall defects can be inspected by the refracted longitudinal wave in the pipe, and the inner wall defects can be inspected by the reflected transverse wave after the wave mode conversion (see Figure A1). When this inspection method is used, the ratio of the inner wall artificial defect depth to the outer wall artificial defect depth should be agreed upon by the supply and demand parties, but it should not exceed the numerical range listed in Table A1. TR
TR: Self-transmitting and self-receiving probe or dual-chip separated probe I; Longitudinal wave
S: Shear wave
Test method for converting longitudinal wave into shear wave
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