This standard specifies the principle, method, comparison specimen, equipment, conditions, steps, evaluation and report of ultrasonic flaw detection on the surface of cold-drawn round steel. GB/T 8361-2001 Method for ultrasonic flaw detection on the surface of cold-drawn round steel GB/T8361-2001 Standard download decompression password: www.bzxz.net

GB/T 8361--2001
This standard is revised on the basis of GB/T8361---1987 "Ultrasonic flaw detection method for cold-drawn round steel surface of bearing steel". The main contents of this revision are as follows:
The name of the standard is changed to "Ultrasonic flaw detection method for cold-drawn round steel surface", and the scope of application of the standard is expanded; the applicable range of cold-drawn round steel diameter is increased from 6mm~50mm to 6mm~80mm; the description of the flaw detection principle is added;
In the flaw detection method, the one-side detection direction is added, that is, the radial direction of the round steel is changed to the detection in two opposite directions of the circumference of the round steel to prevent missed detection due to the directionality of the defect; the level of artificial defects is changed from three to six, and the depth of defects is changed from percentage of diameter to numerical expression; the requirements for flaw detection equipment are added.
This standard replaces GI3/T8361--1987 "Method for ultrasonic flaw detection of cold drawn round steel bearing steel" from the date of implementation. This standard was proposed by the former State Bureau of Metallurgical Industry and drafted by the National Technical Committee for Steel Standardization. The drafting unit of this standard: Baosteel Group Shanghai Wugang Co., Ltd. The main contributors of this standard: Jiang Yijiao, Zheng Yongling, Zhu Fangyun, Ni Xiumei This standard was first issued in November 1987. 66
1 Scope
National Standard of the People's Republic of China
The surface of cold drawn rounds steel-Method for the ultrasonic flaw detection
The surface of cold drawn rounds steel-Method for the ultrasonic inspectionGB/T8361.2001
Replaces GB/T8361-1987
This standard specifies the principles, methods, comparison specimens, equipment, conditions, steps, results and reports of ultrasonic flaw detection on the surface of cold-drawn round steel. This standard is applicable to surface flaw detection of cold-drawn round steel with a diameter of 6mm80mm. It is suitable for detecting defects such as longitudinal cracks and folds on the surface of cold-drawn round steel. bzxz.net
2 Cited 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 parties using this standard should explore the possibility of using the latest versions of the following standards. JB/T100611999A type pulse General technical conditions for reflection ultrasonic flaw detectors JB/I10062--1999 Performance test methods for ultrasonic flaw detection probes 3 Principle of flaw detection
The longitudinal wave emitted by the ultrasonic probe is transmitted to the surface of the round steel at a specific angle of incidence through the coupling medium, and a wave type conversion occurs, generating a surface wave or a transverse wave. When the surface wave or transverse wave propagating on the steel surface or in the steel encounters a defect, it is reflected back and received by the ultrasonic probe. After the signal processing of the instrument, the information of the defect is obtained. 4 Flaw detection method
4.1 The surface wave or transverse wave pulse reflection method is adopted. 4.2 The detection should be carried out in two opposite directions on the circumference of the round steel, as shown in Figure 1. Figure 1 Schematic diagram of flaw detection
4.3 Each side of the surface of the round steel to be inspected should be 100% scanned. 4.4 The length of the undetectable area at the end of the round steel should not exceed 200mm. Approved by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China on December 17, 2001 and implemented on May 1, 2002
5 Comparison specimen
GB/T8361-—2001
5.1 The comparison specimen shall have the same nominal diameter as the round steel to be inspected, and shall be similar in steel type, surface and organizational state. No defects that may affect the evaluation of the flaw detection results shall be allowed.
5.2 Artificial defects shall be processed by the electric spark method or other better methods. In case of dispute, the artificial defects processed by the electric spark method shall prevail. 3 The length of the comparison specimen and the processing position of the artificial defects shall meet the static and dynamic debugging requirements of the sensitivity, as shown in Figure 2. 5.3
Figure 2 Schematic diagram of the processing position of the artificial defects of the comparison specimen 200
5.4 The size of the artificial defects shall be measured by a qualified metrological department using an optical microscope or other methods, and a metrological report on the size of the artificial defects shall be issued.
5.5 The geometric dimensions of the artificial defects of the comparison sample are divided into six levels, see Table 1. The specific levels shall be implemented in accordance with the relevant product standards or agreements. Table 1 Artificial defect size
Allowable error
5.6 When there are special requirements for the geometric dimensions of artificial defects, the supply and demand parties shall negotiate separately. 6 Flaw detection equipment
Unit: mm
Not more than 2 times the depth
Flaw detection equipment generally includes: flaw detector, probe, probe control device, mechanical transmission equipment and other auxiliary devices. 6.1 Flaw detector
6.1.1 Use a single-channel or multi-channel A-type pulse reflection ultrasonic flaw detector, and its performance indicators shall comply with the provisions of J3/T10061. The flaw detector should be calibrated regularly by the metrology department. 6.1.2 The flaw detector should have sufficient repetition frequency adjustment range to adapt to changes in the flaw detection speed. 6.1.3 Other performances of the flaw detector should meet the needs of automatic flaw detection and have sufficient anti-field interference capabilities. 6.2 Probe
6.2.1 Single probe or multiple probes can be used. Line focusing acoustic lens can also be added to the probe. The chip length or diameter of a single probe should not be greater than 20 mm.
6.2.2 The working frequency of the probe can be selected within 2.5MHz~10MHz. 6.2.3 The performance of the probe should comply with the provisions of JB/T10062. 6.3 Probe control device
6.3.1 The device should have good tracking ability within a certain range, that is, to ensure that the incident angle and verticality of the sound wave relative to the round steel remain stable at a certain flaw detection speed.
6.3.2 There should be a firm and flexible probe holder to accurately adjust the probe. 8
6.4 Mechanical transmission device
GB/T 8361—2001
The device should ensure that the round steel is smoothly sent through the probe control device at the selected speed, and ensure that the round steel and the probe maintain good stability.
7 Inspection conditions
The straightness, out-of-roundness and end quality of the round steel to be inspected shall comply with the corresponding product standards, and the surface of the round steel shall be clean, free of iron filings and dirt.
7.2 The coupling agent can use clean, bubble-free water or oil with good acoustic coupling performance. Anti-rust measures should be taken during water immersion inspection. 7.3 The inspector shall hold a Grade 1 or above ultrasonic inspector qualification certificate issued by the non-destructive testing qualification certification department, and anyone who issues a report shall hold a Grade 1 or above ultrasonic inspector qualification certificate. 8 Inspection steps
8.1 Sensitivity debugging
Each time a flaw detection is performed or the diameter of the round steel to be inspected changes, a comparison sample shall be used for sensitivity debugging. 8.1.1 Static sensitivity debugging
8.1.1.1 Adjust the probe and probe control device to generate the selected waveform, And obtain the artificial defect echo. 8.1.1.2 I. The alarm amplitude of the defect echo can be selected within 50%~80% of the vertical full scale of the display screen. The waveform should be clear and no clutter should appear in the alarm gate.
8.1.2 Dynamic adjustment of sensitivity
8.1.2.1 Perform dynamic adjustment of sensitivity at the selected flaw detection speed. 8.1.2.2 On the basis of static adjustment of sensitivity, appropriately increase the sensitivity so that the comparison sample passes at least 5 times, and all artificial defects should alarm each time. Otherwise, it should be readjusted. 8.2 Flaw detection
8.2.1 Based on the dynamic adjustment of sensitivity, flaw detection is carried out batch by batch. 8.2.2 During the flaw detection process, at regular intervals (≤2h) or at the end of the flaw detection of the same specification, the sensitivity should be verified with a comparison sample. When the sensitivity does not meet the requirements, the sensitivity should be re-adjusted and the round steel to be tested after the last calibration should be re-tested. 9 Evaluation of flaw detection results
The evaluation of flaw detection results should be carried out by comparing the echo amplitude of the flaw of the round steel to be tested with the echo amplitude of the artificial flaw. , when the defect echo amplitude is lower than the artificial defect echo amplitude, it is a qualified product; when it is not lower than the artificial defect echo amplitude, it is a defective product. 10 Flaw detection record and flaw detection report
The flaw detection report shall at least include the following contents:
a) Brand, furnace batch number and specification of the round steel to be inspected; b) Flaw detection standard number and artificial defect level; () flaw detector, probe, coupling agent and flaw detection method; d) Flaw detection evaluation results (flaw detection quantity, qualified quantity and unqualified quantity), flaw detection date; e) Name of the flaw detection operator and the person who issues the report. 69
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