JB/T 5000.14-1998 General technical conditions for heavy machinery non-destructive testing of steel castings
Some standard content:
ICS19.100
J04
JB
Machinery Industry Standard of the People's Republic of China
JB/T5000.14-1998
General Technical Conditions for Heavy Machinery|| tt||Non-destructive testing of steel castings
The heaw mechanical gener al techniques and standardsNon-destructive testing of steelcasting1998-09-30 Released
National Machinery Industry Bureau
Released
1998- 12-01 Implementation
JB/T5000.14-1998
Foreword
Scope·
1
2
Quoted standards|| tt||3 Application requirements
Ultrasonic flaw detection and its quality grade
4
Ray transillumination flaw detection and its quality grade
5
6 Magnetic particle flaw detection and its quality level
7 Penetration testing and its quality level
Appendix A (standard appendix) Transverse wave inspection items for steel castings
times
Appendix B (standard Appendix) Method for determining the minimum distance (f) from the ray source to the workpiece Appendix C (Appendix of the prompt)
Point defect rating diagram
6
14
19
25
29
I
JB/T5000.14-1998
Foreword
Appendix A and Appendix B of this standard are It is a standard appendix. Appendix C of this standard is a reminder appendix.
This standard is proposed and managed by the Metallurgical Equipment Standardization Technical Committee of the Ministry of Machinery Industry. The unit responsible for drafting this standard: Second Heavy Machinery Group Company. The organization participating in the drafting of this standard: Xi'an Heavy Machinery Research Institute. The main drafter of this standard: Chen Yuanliang.
I
1 Scope
Machinery Industry Standards of the People's Republic of China
General Technical Conditions for Heavy Machinery
Non-destructive testing of steel castings
-destrudtivetesting df steel castingJB/T5000.14—1998
This standard specifies the non-destructive testing methods for ultrasonic flaw testing, radiographic flaw testing, magnetic particle testing, and penetrant testing applied to steel castings, as well as the corresponding quality levels.
This standard is applicable to ultrasonic flaw detection of carbon steel and low alloy steel castings with a thickness equal to or greater than 30mm. It is not applicable to ultrasonic flaw detection of austenitic cast steel and other castings (the ultrasonic flaw detection method used in this standard is limited to Type A Display pulse reflection method), X-ray and Y-ray photography of steel castings with a thickness of 5~30Qmm, magnetic particle inspection of surface and near-surface defects of ferromagnetic steel castings, and penetrant inspection of surface opening defects of steel castings.
Any non-destructive testing inspection stipulated in this standard must specify the type of non-destructive testing method, testing standard, testing location, testing location, etc. Depth range (referring to the use of ultrasonic dual-element probes for near-surface flaw detection), detection period, quality level or universal grade), etc. are stipulated. 2 Referenced standards
The provisions contained in the following standards constitute provisions of this standard by being quoted in this standard. At the time of publication, the editions indicated were valid. All standards are subject to revision and parties using this standard should explore the possibility of using the latest version of the standard listed below. GB3721—83
GB 4792—84
GB 5097—85
GB5618—85
ZBJ04 003—87
ZBJ04 006—87||tt ||3 Application requirements
Magnetic particle flaw detector
Basic standards for radiation health protection
Indirect evaluation method of black light source
Linear image quality meter
Control Methods for penetrant testing of material quality
Magnetic particle testing methods for steel materials
3.1 Application principles of non-destructive testing
3.1.1 When applying non-destructive testing, it must be based on the necessity of using non-destructive testing for steel castings Based on the principles of safety, reliability, economy and feasibility, the types of non-destructive testing methods, testing standards and quality acceptance levels are determined. 3.1.2 If this standard cannot meet the requirements of the adopter, supplementary provisions may be added, other standards may be selected, or special standards may be formulated. 3.1.3 Ultrasonic flaw detection and radiographic flaw detection are mainly used to detect internal defects of steel castings. However, since the above two methods have their own characteristics, their advantages should be fully utilized when using them. Magnetic particle inspection is used to detect defects on the surface and near-surface of steel castings, while penetrant inspection can only find defects in surface openings. Therefore, penetrant inspection is generally only used for surface inspection of non-ferromagnetic materials (non-ferromagnetic materials cannot be used in the National Machinery Industry The Bureau approved the implementation on 1998-12-01 on September 30, 1998
1
is magnetized).
JB/T5000.14—1998
3.1.4 Non-destructive testing for quality evaluation of the final state of steel castings (when delivered), the testing period must be arranged after the final hot processing Carry out: For materials with a tendency of delayed cracking, the flaw detection period must be arranged after sufficient aging (the flaw detection period for the welded parts of such materials must be arranged after 24 hours after welding); at the same time, magnetic particle flaw detection or penetrant flaw detection must also be arranged Arranged to be carried out after final machining (or surface grinding).
3.2 Flaw detection personnel
3.2.1 Non-destructive testing personnel who detect, write and issue test result reports on steel castings must hold national The technical qualification certificates for non-destructive testing personnel issued by relevant departments are the corresponding types of flaw detection methods and the corresponding technical levels. 3.2.2 The technical qualification certificates for non-destructive testing personnel are divided into ultrasonic flaw detection personnel qualification certificates, radiographic flaw detection personnel qualification certificates, and magnetic particle flaw detection personnel qualification certificates. , Penetration flaw detection personnel qualification certificate; various flaw detection methods are divided into level I, level II, and level II. Level I is junior, level II is intermediate, and level IIIII is advanced: flaw detectors who hold technical qualifications of level II and above. 3.2.3 Personnel engaged in non-destructive testing of cast steel should also have extensive knowledge of cast steel materials, casting technology, metal heat treatment, welding technology and defects in cast steel. 3.2.4 In addition to having good physical fitness, non-destructive inspection personnel should also meet the following requirements for vision: a) The corrected vision should not be less than 1.0, and should be reviewed once a year: b) Personnel engaged in radiographic evaluation should be able to distinguish a group of high-definition objects 400mm away 0.5mm, printed letters with a spacing of 0.5mm;) Personnel engaged in magnetic particle inspection and penetrant inspection must not be color blind or color weak. 4 Ultrasonic flaw detection and its quality level
4.1 Ultrasonic flaw detector
4.1.1 Type A pulse reflection ultrasonic flaw detector should be selected, whose generating, receiving and amplifying frequency is at least 1~5MIHz4.1.2 Instrument The horizontal linearity, vertical linearity and attenuator (or gain) accuracy should comply with the relevant standards. 4.1.3 When the combined sensitivity of the instrument and probe reaches the flaw detection sensitivity at the maximum sound range of the casting being detected, at least 10dB of sensitivity margin should remain.
4.2 Probe
4.2.1 The frequency of longitudinal wave straight probe is generally 2~2.5MHz, and the chip diameter is in the range of 10~3Qmm. When the flaw detection surface of the inspected steel casting is rough, it is recommended to Use a longitudinal wave straight probe with a soft protective film. 4.2.2 It is recommended to use a 2~2.5MHz, 12~25mm longitudinal wave dual-element probe. The acoustic insulation between the two elements must be good. When the detection cross-section is less than or equal to 25mm, it is recommended to use a dual-element probe with an included angle of 12°. 4.2.3 For the assessment and location of defects, probes of other types, frequencies and sizes are allowed to be used. 4.3 Test block
4.3.1 The comparison test block is made of cast carbon steel or cast low alloy steel. Its ultrasonic characteristics should be similar to the casting being inspected. The material used to make the comparison test block must be subjected to ultrasonic flaw detection in advance. It is not allowed There are internal defects equal to or greater than Φ2mm equivalent (the comparison test block for dual element probes is not allowed to have internal defects equal to or greater than Φ1mm equivalent). The name, number, material, and sound transmittance of the test block should be marked on the side of the comparison test block.
4.3.2 The flat-bottomed hole test block is used to adjust the flaw detector according to 4.7.2 to determine the flaw detection sensitivity. 4.3.3 The specifications of the comparison test block for longitudinal wave straight probes are shown in Figure 1, and its dimensions are shown in Table 1. When the thickness of the steel casting to be detected is greater than 250mm2
JB/T5000.14-1998
, a test block with a maximum detection distance equal to the thickness of the casting must be made to supplement. L± 0. 5
B±0.5
51
?
10
rest of learning
0.03A
0.03A
eo.oa
D0.15A
Figure 1
Comparative test block diagram for longitudinal wave straight probe
Table 1
Comparison test block size for longitudinal wave straight probe
No.
No.
CSZ-1
CSZ-2
CSZ-3
CSZ-4
CSZ-5
CSZ-6
4.3.4
Total length L
45
70||tt| |95
170
270
B+20
Detection distance B
25
50
75|| tt | tt||Test block diameter
50
50
50
75
100
125
its product| |tt||25±0.1
25±0.1
10F92
250±0.5
1
t
2||tt ||5A256
?
9×43±0.05
Figure 2 Comparative test block diagram for longitudinal wave dual element probe
20 noon 09
0.03A
9× 43
0.034
E032
Table 29 detection distance of flat-bottomed holes 1 Detailed list serial number
2
3| |tt||4
5
6
7
mm
Flat bottom hole diameter d
6
3
1
mm
4.4 coupling agent
5
10
15
JB/T5000.14-1998
20
25
30
35
40
45
The coupling agent should have good sound transmission , wettability, non-corrosive finished products and substances with suitable acoustic impedance. Usually, engine oil, a mixture of engine oil and yellow glycerin, paste or water can be used as coupling agent; the same coupling must be used when adjusting instruments, calibrating instruments and flaw detection. agent. 4.5 Requirements for steel castings
4.5.1 Before ultrasonic flaw detection, steel castings should undergo at least one austenitizing heat treatment. 4.5.2 The detection period of the final evaluative ultrasonic flaw detection should be arranged after the final heat treatment and rough machining. 4.5.3 Castings should be arranged for ultrasonic flaw detection after passing the visual inspection. There are no foreign objects that affect ultrasonic flaw detection on the flaw detection surface and bottom surface of the casting. The processed surface should reach R6.3μm, and the unprocessed surface needs to be polished and smooth. 4.5.4 Mechanical processing procedures that hinder ultrasonic flaw detection should be arranged after ultrasonic flaw detection. 4.6 Judgment of the detectability of steel castings
The detectability must be judged before flaw detection. Only after the requirements are met can the flaw detection inspection be carried out. First, put the instrument suppression\knob in the zero position, and use the frequency of 22.5M ratio. Frequency longitudinal wave straight probe is used to detect the maximum detection distance (thickest part) of the steel casting or the place with the most reflected clutter: the noise signal reflection amplitude ratio at this time is selected as the reflection of the longitudinal wave with the same sound path flaw detection sensitivity. When the echo is lower than 8B, the casting is suitable for ultrasonic flaw detection (that is, the detectability meets the requirements). If the above requirements cannot be met, the flaw detection frequency can be reduced to 1MH and then tested according to the above method. If the above requirements are met at this time, this frequency can be used for flaw detection, but this must be stated in the flaw detection report. If the results of the reduced frequency test still cannot meet the ultrasonic detectability requirements, heat treatment should be used to improve the sound transmission of the casting, and ultrasonic flaw detection can only be carried out after the detectability requirements of ultrasonic flaw detection are met. 4.7 Instrument adjustment
4.7.1 Horizontal scan line adjustment
Set the suppression knob in the instrument to the zero position, and use the test block to set a certain ratio for the maximum detection distance of the steel casting to be detected. Adjust on the horizontal scan line.
4.7.2 Instrument adjustment for general-level flaw detection sensitivity of longitudinal wave straight probe Use a set of Φ6mm flat-bottomed hole test blocks specified in this standard (the thickness of the test block includes the maximum thickness of the tested piece), and make a Φ6mm\distance-amplitude "curve. This is the sensitivity curve used to judge the size of defects during flaw detection. The curve can be drawn on graph paper or directly on the oscilloscope screen of the instrument. When marking the distance-amplitude" curve on the oscilloscope screen, if it is inspected If the ultrasonic attenuation within the thickness of the casting exceeds the dynamic range of the display system, the curve can be marked segmentally. 4.7.3 Instrument adjustment for the special-grade flaw detection sensitivity of the longitudinal wave straight probe. First, make a "distance-amplitude" curve of Φ6mm according to the method in 4.7.2, and then increase the sensitivity by a gain value of 12dB during flaw detection. At this time, the distance of Φ6mm-12dB -amplitude" curve, which is equivalent to the "distance-amplitude" curve of Φ3mm. 4.7.4 Instrument adjustment of longitudinal wave dual element probe flaw detection sensitivity. First, the reserve amount reserved in the attenuator (or gainer) of the instrument must not be less than the surface roughness compensation amount. . Then test a set of Φ3mm flat-bottom hole dual-element probes specified in this standard and use a comparison test block; adjust the instrument so that the echo amplitude of the flat-bottom hole with the highest reflected wave reaches 80% of the full scale of the instrument's fluorescent screen. In this case, do not change any parameters of the instrument. Test flat-bottomed holes with different distances one by one, and make a Φ3mm\distance-amplitude curve at a close distance.
4
4.7.5 Compensation for surface roughness and material effects JB/T5000.14—1998
When the flaw detection surface of the workpiece is rougher than the flaw detection surface of the comparison test block, when the workpiece When the internal sound transmission is worse than the sound transmission inside the test block, or when both of the above exist, the flaw detection sensitivity should be compensated for the sound energy loss. The following method can also be used to measure sound energy loss: first, select one or several places on the casting whose internal material and surface roughness can basically represent other parts. At the same time, the part where the detection surface is basically parallel to the bottom surface is the measurement point, and then select a piece. For a test block whose thickness is basically the same as the thickness of the casting at the measurement point, adjust the attenuator of the instrument so that the bottom reflection wave height (or average wave height) of the measurement point is consistent with the bottom reflection wave height of the test block, and read out the two bottom surface reflections. The decibel difference of waves, this difference is the sound energy loss caused by surface roughness and internal sound transmission. 4.7.6 After the instrument is adjusted, when making and using the distance-amplitude\curve, except for the attenuator (or graduated gain controller) on the instrument, all other devices (knobs) on the instrument and the probes used must not be changed. 4.8 Flaw detection method, location and sensitivity
4.8.1 Flaw detection method
Ultrasonic flaw detection of steel castings is generally based on the longitudinal wave vertical reflection method. If necessary, flaw detectors can use other types of probes as auxiliary detection.
4.8.2 Carry out inspection according to the flaw detection location, range, inspection depth and corresponding probe specified in the ordering technical documents or drawings. 4.8.3 Flaw detection sensitivity
Adjust the instrument and flaw detection according to the flaw detection sensitivity level specified in the ordering technical documents or drawings. 4.8.3.1 General level refers to the use of a Φ6mm flat-bottomed hole as the flaw detection sensitivity when using a longitudinal wave straight probe. 4.8.3.2 Special grade refers to the flaw detection sensitivity that is 12dB higher than the Φ6mm flat-bottomed hole flaw detection sensitivity when using a longitudinal wave straight probe (i.e. Φ6mm-12dB)
General level flaw detection sensitivity flaw detection. 4.8.3.4 The flaw detection sensitivity of dual-element probes is generally Φ3mm flat-bottom hole. 4.9 Scanning requirements and defect determination
4.9.1 Movement of the probe
In order to prevent defects from being missed, the moving speed of the probe shall not be greater than 150mm/s, and at least the transducer must be stacked for each scan 15% of the diameter (or width) of the device. Parts that cannot be scanned due to limitations of the casting geometry must be noted in the flaw detection report. 4.9.2 Calibration of defects
4.9.2.1. For defects whose reflected wave height continuously reaches or exceeds the distance-amplitude curve of the flaw detection sensitivity level specified in the drawing or technical document, the defect reflection area (reflection range) must be divided according to the sensitivity of this distance-amplitude curve. 4.9.2.2 Whenever the back wave caused by a defect continuously reduces by 12dB or more, the reflection area of ??the defect area must also be divided according to the 12dB reduction value of the back wave.
4.9.2.3 Division of the reflection area of ??the defect area: When the defect reflection occurs in the above 4.9.21 and 4.9.22 situations, move the probe so that the defect wave height is equal to the distance-amplitude curve of the flaw detection sensitivity level, Or the range surrounded by the trajectory of the center point of the probe element when the bottom wave caused by the defect is reduced by 12dB is the reflection area of ??the defect area. 4.9.2.4 The size of the defect area is calculated based on the maximum size of the defect reflection range and its perpendicularity. The product of the largest dimensions in the direction. When the distance between the edges of the defective area is less than 25mm, two or more defective areas are treated as one large defective area when calculating the area, and the total area is equal to each adjacent defective area. 4.9.2.5 Because the detection distance (depth) is very long or the detection surface is curved, the defect area marked on the surface of the casting may be the same as the actual defect 5bzxz.net
JB/T5000.14-1998||tt ||There is a big difference in the actual size of the reflection area. In this case, the sound beam diffusion pattern should be comprehensively considered and corrected to reflect the defect size more realistically
4.9.2.6 When the detection surface of the casting is the same. When conducting longitudinal wave inspection in areas where the bottom surface is parallel, the area where the bottom wave is reduced by 12dB or more and there is no defective reflected wave should be carefully inspected to confirm whether it is caused by poor probe contact, insufficient coupling agent, or the direction of the defect is not conducive to the reflection of ultrasonic waves. If so. If the reason for the loss of reflected echo is unknown, it should be taken seriously and further research should be carried out (such as improving the flaw detection sensitivity or changing the flaw detection frequency detection, or using other feasible non-destructive flaw detection methods); if the conclusion still cannot be reached, the supply and demand parties will Negotiate or ask the relevant departments to handle it.
4.9.2.7 Calibration of defects found by dual element probes shall be handled according to the flaw detection sensitivity specified in each drawing or relevant technical documents
4.9. 3. Verification of flaw detection sensitivity
The flaw detection sensitivity should be checked regularly during flaw detection. At the end of the flaw detection work, the flaw detection sensitivity should also be checked. When the sensitivity is found to have changed, it needs to be recalibrated and the flaw detection work completed since the previous verification must be re-calibrated. Carry out flaw detection. 4.10 Acceptance quality level
4.10.1 The selection of the acceptance level for ultrasonic flaw detection of steel castings should be determined based on the use conditions, size and shape, material, defect situation and distribution of the castings, and taking into account the steel castings The specific conditions of production. The acceptance level should be specified in the relevant technical documents or drawings. 4.10.2 The classification of ultrasonic quality acceptance levels of steel castings is shown in Table 3 (excluding defects found by dual probes). Table 3 Classification of defect levels || tt||Quality level
1
2
3
4
5
6
7||tt ||Defect area
mm
484
900
1936
3025
4900
7744||tt| |10000
Maximum length of defects allowed
mm
40
60
80
100
130||tt || 150 | The equivalent size is used to measure the allowable value of defects found in flaw detection, and (its value) is separately stipulated by the design department and both supply and demand parties.
4.10.4 Other acceptance criteria proposed by the designer or agreed by both the supply and demand parties. 4.11 Flaw detection report
The flaw detection report should include the following contents.
4.11.1 The unit entrusted with flaw detection, flaw detection surface report number, steel casting name, production number, heat number, drawing number, material, heat treatment status, flaw detection status, flaw detection standards.
4.11.2 Use instruments, probes, frequencies, coupling agents, longitudinal wave straight probe sensitivity 4.11.3 Mark the detection area, use of probes, and exploreability on the casting sketch, if there are geometric restrictions and undetected parts , it must also be 6
3. Mark the inspection area, probe to be used, and detectability on the casting sketch. If there are parts that are not inspected due to geometrical restrictions, they must also be marked.3. Mark the inspection area, use of probes, and explorability on the casting sketch. If there are parts that are not inspected due to geometric restrictions, they must also be 6
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.