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GB/T 34370 consists of the following eleven parts under the general title Nondestructive testing of amusement equipments:
——Part 1: General requirement;
——Part 2: Visual examination;
——Part 3: Magnetic particle testing;
——Part 4: Penetrant testing;
——Part 5: Ultrasonic testing;
——Part 6: Radiographic testing;
——Part 7: Eddy current testing;
——Part 8: Acoustic emission testing;
——Part 9: Magnetic flux leakage testing;
——Part 10: Magnetic memory testing;
——Part 11: Ultrasonic guided wave testing.
This is Part 5 of GB/T 34370.
This part is developed in accordance with the rules given in GB/T 1.1-2009.
This part was proposed by and is under the jurisdiction of SAC/TC 250 National Technical Committee on Ropeway and Entertainment Facilities of Standardization Administration of China.
Nondestructive testing of amusement equipments - Part 5: Ultrasonic testing
1 Scope
This part of GB/T 34370 specifies the ultrasonic testing method for amusement equipment as well as quality grading and ultrasonic thickness measurement requirements.
It is applicable to the ultrasonic testing of metal raw materials, parts and components as well as welded joints of both amusement equipment and in-use amusement equipment.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 7233.1 Steel castings - Ultrasonic examination - Part 1: Steel castings for general purposes
GB/T 11344 Non-destructive testing - Practice for measuring thickness by ultrasonic pulse-echo contact method
GB/T 12604.1 Non-destructive testing - Terminology - Terms used in ultrasonic testing
GB/T 20306 Amusement devices terminology
GB/T 20737 Non-destructive testing - General terms and definitions
GB/T 27664.1 Non-destructive testing - Characterization and verification of ultrasonic test equipment - Part 1: Instruments
GB/T 27664.2 Non-destructive testing - Characterization and verification of ultrasonic test equipment - Part 2: Probes
GB/T 29302 Non-destructive testing instruments - Characterization and verification of phased array ultrasonic examination systems
GB/T 34370.1 Nondestructive testing of amusement equipments - Part 1: General requirement
JB/T 8428 Non-destructive testing - General specification for ultrasonic blocks
JB/T 9214 Non-destructive testing - Test methods for evaluating performance characteristics of A-scan pulse-echo ultrasonic testing systems
JB/T 10062 Testing methods for performance of probes used in ultrasonic flaw detection
JB/T 11604 Non-destructive testing instruments - Ultrasonic thickness gauge
JB/T 11731 Non-destructive testing - General specification for ultrasonic phased array probe
JB/T 11779 Non-destructive testing instrument - Specifications for phased array ultrasonic testing instruments
3 Terms and definitions
For the purpose of this standard, the terms and definition specified in GB/T 12604.1, GB/T 20306, GB/T 20737 and GB/T 34370.1 and the following apply.
3.1
loss of back reflection caused by flaws BG/BF(dB)
the ratio of the first bottom echo amplitude BG in the flaw-free area near the flaw area to the first bottom echo amplitude BF in the flaw area, it is expressed by dB
3.2
basic and scanning sensitivities
f
basic sensitivity is generally referred to as record sensitivity, it is usually used for sizing and grading of flaws, while scanning sensitivity mainly refers to the actual test sensitivity. for fear of missing the record flaws or certain specific flaws, and in order to ensure the safety of amusement equipment, the higher scanning sensitivity shall be adopted in actual testing. In principle, the scanning sensitivity shall not be lower than the basic sensitivity
3.3
focusing angle beam probe
ultrasonic angle probe converging the ultrasonic beam with a focusing method of lenticular, emissive, and a curved crystal form to improve the test sensitivity
3.4
tip diffraction
phenomenon that wavefront bends around the edge of the flaw and spreads in the center of the circle when it passes through the flaw during the propagation of ultrasonic waves
3.5
maximum tip reflected wave
when the tip echo amplitude of flaw reaches the maximum (namely, the instantaneous amplitude position before the tip echo peak of flaw starts to fall down), such echo is referred to as maximum tip reflected wave of flaw
3.6
echo dynamic patterns
dynamic pattern is the envelope line of probe movement distance and the echo amplitude variation of corresponding flaw reflector
3.7
base material nominal thicknesses
t
a) as for plate butt joints, if the base metal thicknesses at both sides of weld are the same, t is the thickness of base metal; if not, t is the nominal thickness of the thinner side of the base metal;
b) as for T-shaped welded joint, t is the nominal thickness of web
3.8
tube diameter
Do
outside diameter of a tube
3.9
axis diameter
diameter of solid axis refers to the outer diameter of axis, where there is a step, it refers to the diameter of working surface;
diameter of hollow axis includes inner diameter (DI) and outer diameter (Do), where there is a step, the inner and outer diameters are determined according to the diameter of working surface
3.10
a cluster of flaws
five or more flaw reflected signals are present over the range of 50mm sound path distance of fluorescent screen scanning line; or five or more flaw reflected signals are present on 50mm×50mm testing surface in the same depth range, and all the reflected wave amplitudes are greater than the basic reflected wave amplitude of certain equivalent flaw
3.11
flaw height
size of flaw in wall thickness direction
3.12
flaw evaluation zone
a zone with certain size set to evaluate the quantity and intensity of flaws in quality grading evaluation, which may be square or rectangular, flaw evaluation zone shall be selected in the area with the most serious flaws
3.13
inspection distance
it refers to the one-through sound path distance during test with ultrasonic normal probe
4 Method summary
4.1 Ultrasonic wave is the mechanical wave above 20kHz and the frequency of ultrasonic wave used in ultrasonic testing of industrial nondestructive testing is generally between 0.5MHz and5MHz.
4.2 Ultrasonic wave propagates at a certain speed and direction in a material and will be reflected or diffracted in case of encountering a heterogeneous interface (such as a flaw or the bottom of the object to be tested) with different acoustic impedance.
4.3 Reflective ultrasonic testing is to test flaw or measure thickness by taking advantage of this reflection phenomenon. Figure 1a) to Figure 1c) are schematic diagrams for A-scan pulse obliquely incident ultrasonic testing, A-scan pulse vertically incident ultrasonic testing and A-scan pulse-echo ultrasonic testing. Figure 2 is the schematic diagram for phased array ultrasonic testing.
a) A-scan pulse obliquely incident ultrasonic testing b) A-scan pulse vertically incident ultrasonic testing c) A-scan pulse-echo ultrasonic thickness measurement
Figure 1 Schematic diagram for A-scan pulse-echo ultrasonic testing
a) Focusing
b) Sound beam control
c) Phased array B scan
d) Comparison of test effects
Figure 2 Schematic diagram for phased array ultrasonic testing
5 Safety requirements
5.1 This clause does not list all the safety requirements for testing. Users adopting this part shall establish safety guidelines prior to testing.
5.2 The safety requirements during testing shall include at least:
a) the testing personnel shall observe the safety requirements of the site for the test object, wear protective clothing and relevant protective equipments as required on the testing site;
b) the wall temperature of the tested workpiece during testing shall be within the temperature range for the normal working of couplant
c) attention shall be paid to that couplant will lead to defective insulation and electrical shorts during ultrasonic testing;
d) after amusement equipment is put into operation, attention shall be paid to the temperature of the tested workpiece to avoid scalding.
6 Requirements for personnel
Personnel engaged in ultrasonic testing of amusement equipment shall comply with the relevant provisions of GB/T 34370.1.
7 Testing equipment
7.1 Basic requirements
7.1.1 Ultrasonic testing equipment shall include testing instrument and probe at least.
7.1.2 Ultrasonic testing equipment shall be accompanied with product quality certificate or qualification certificate.
7.2 Testing instrument
7.2.1 Basic requirements for A-scan pulse-echo ultrasonic testing instrument
a) A-scan pulse-echo ultrasonic testing instrument has an error of no more than 10% between the actually measured repetition frequency of transmitted pulse and the nominal value, of no more than 20% between the actually measured voltage of transmitted pulse and the nominal value, and of no more than 10% between the actually measured width of transmitted pulse and the nominal value. The rise time of transmitted pulse is no more than 25ns;
b) the operating frequency of A-scan pulse-echo ultrasonic testing instrument, if measured as -3dB, shall at least include the range of 0.5MHz~10MHz and the difference between the actually measured upper/lower limit on each frequency band and the nominal value is no more than 20%;
c) A-scan pulse-echo ultrasonic testing instrument shall have continuously adjustable attenuation or gain of above 80dB; its step level is no more than 2dB per gear and its accuracy is no more than 1.7dB for the accumulative error of any continuous 20dB and no more than 3dB for the accumulative error of any continuous 60dB;
d) the performance indicators are tested according GB/T 27664.1.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Method summary
5 Safety requirements
6 Requirements for personnel
7 Testing equipment
8 Testing process specification
9 Preparation for testing
10 Ultrasonic testing and quality grading of raw materials and parts and components
11 Ultrasonic testing of welded joint for amusement equipment
12 Ultrasonic testing of in-use amusement equipment
13 Pulse reflected ultrasonic thickness measurement
14 Ultrasonic testing report
Annex A (Normative) Performance requirements of double crystal normal probe
Annex B (Normative) Transverse wave testing of steel plate for amusement equipment
Annex C (Normative) Transverse wave testing of steel forging for amusement equipment
Annex D (Informative) Method for adjusting bottom echo sensitivity of workpiece
Annex E (Normative) Ultrasonic angle beam probe testing of steel forgings for amusement equipment
Annex F (Normative) Axial transverse wave testing of seamless steel tube for amusement equipment
Annex G (Normative) Ultrasonic testing method and quality grading for cast iron components
Annex H (Normative) Ultrasonic testing of austenitic stainless steel butt welded joint
Annex I (Normative) Determination of sound energy transmission loss difference
Annex J (Informative) Echo dynamic pattern
Annex K (Normative) Phased array ultrasonic testing method
Annex L (Normative) Flaw height determination by -6dB drop method
Annex M (Normative) Typical calibration block for measurement
