GB/T 34370.3-2017 English PDF (GBT34370.3-2017)

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GB/T 34370.3-2017: Nondestructive testing of amusement equipment -- Part 3: Magnetic particle testing
GB/T 34370.3-2017
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 97.200.40
Y 57
Nondestructive testing of amusement equipment -
Part 3. Magnetic particle testing
ISSUED ON. SEPTEMBER 29, 2017
IMPLEMENTED ON. APRIL 01, 2018
Issued by. General Administration of Quality Supervision, Inspection and
Quarantine of the People's Republic of China;
Standardization Administration of the People's Republic of
China.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Terms and definitions ... 5
4 Method summary ... 6
5 Safety requirements ... 7
6 Personnel requirements ... 8
7 Testing equipment and apparatus ... 8
8 Testing process procedures ... 13
9 Testing ... 14
10 Retesting ... 22
11 Demagnetization ... 22
12 Magnetic particle testing quality grading ... 23
13 Magnetic particle testing report ... 24
Annex A (informative) Waveform of various magnetizing electric currents,
ammeter indication and conversion relationship ... 26
Annex B (informative) Typical magnetization methods for welds ... 27
Nondestructive testing of amusement equipment -
Part 3. Magnetic particle testing
1 Scope
This Part of GB/T 34370 specifies the yoke method, coil method and current
flow method of the magnetic particle testing method and the requirements for
quality grading of amusement equipment.
This Part applies to the testing of defects on the surface and near surface of
ferromagnetic raw materials, parts and welded joint of amusement equipment.
This Part does not apply to the testing of austenitic stainless steel and other
non-ferromagnetic materials.
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 5097 Non-destructive testing - Penetrant testing and magnetic particle
testing - Viewing conditions
GB/T 11533 Standard for logarithmic visual acuity charts
GB/T 12604.5 Non-destructive testing - Terminology - Terms used in
magnetic particle testing
GB/T 20306 Amusement devices terminology
GB/T 20737 Non-destructive testing - General terms and definitions
GB/T 23907 Non-destructive testing - Shims for magnetic particle testing
GB/T 34370.1 Nondestructive testing of amusement equipment - Part 1.
General requirement
JB/T 6063 Non-destructive testing - Materials for magnetic particle testing
JB/T 8290 Non-destructive testing instruments - Magnetic particle flaw
6 Personnel requirements
For personnel engaged in the magnetic particle testing of amusement
equipment, in addition to complying with the relevant provisions of GB/T
34370.1, the magnetic particle testing personnel shall have an uncorrected or
corrected visual acuity of not less than 5.0 (the decimal number is 1.0), and
shall not have color blindness. The testing method shall comply with the
provisions of GB/T 11533. The testing personnel shall be subjected to an eye
exam every 12 months.
7 Testing equipment and apparatus
7.1 Magnetic particle testing equipment
7.1.1 Basic requirements
The magnetic particle testing equipment shall comply with the provisions of
JB/T 8290.
When using the yoke maximum spacing, the AC yoke shall have a lifting power
of at least 45 N; the DC (including rectified current) yoke or permanent yoke
shall have a lifting power of at least 177 N.
7.1.2 Power-off phase controller
When using the residual magnetic field method for testing, the AC flaw detector
shall be equipped with power-off phase controller.
7.1.3 Black light irradiance and wavelength
When using the fluorescent magnetic particle testing, the black light (UV-A)
used shall comply with the provisions of GB/T 5097, and the irradiation intensity
on the surface of the workpiece to be tested shall be greater than or equal to
1000 μW/cm2. Its wavelength shall be 315 nm to 400 nm, and the peak
wavelength is approximately 365 nm.
7.1.4 Demagnetization device
The demagnetization device shall ensure that the surface residual magnetic
field after the workpiece is demagnetized is less than or equal to 0.3 mT (240
A/m).
7.1.5 Auxiliary equipment
Generally include the following equipment.
meters, illuminometers, magnetic field strength meters, milli-Tesla meters,
Gauss meters, etc., shall be calibrated at least once a year.
8 Testing process procedures
8.1 General testing process procedures
Organizations engaged in the magnetic particle testing of amusement
equipment shall formulate general testing process procedures in accordance
with the requirements of GB/T 34370.1 and this Part, and the contents shall at
least include the following elements.
a) document number;
b) scope of application;
c) implemented standards and regulations;
d) qualification of testing personnel;
e) name and model, etc. of test equipment and apparatus;
f) type and grade of magnetic particle;
g) surface state of the workpiece to be tested;
h) timing of testing;
i) magnetic ink concentration and method of applying magnetic particle;
j) magnetization method and magnetization specification;
k) testing sensitivity calibration and standard shim;
l) analysis and interpretation of the testing process and magnetic particle
indication;
m) assessment and grading of testing results;
n) test record and report format;
o) data archiving;
p) signature of preparing (level), reviewing (level) and approving personnel,
date.
8.2 Testing process card
When the coil is larger than 2 times and less than 10 times the cross-sectional
area of the workpiece to be tested, the magnetizing electric current of the coil
is calculated according to formula (4).
where.
(NI)h - the NI value calculated by the high fill factor coil of formula (3);
(NI)l - the NI value calculated by the low fill factor coil of formula (1) or formula
(2);
Y - the ratio of the cross-sectional area of the coil to the cross-sectional area
of the workpiece.
9.4.2.6 The above formula does not apply to workpieces with a length to
diameter ratio (L/D) of less than 2. For workpieces with a length to diameter
ratio (L/D) of less than 2, if the coil method is to be used, the magnetic pole
lengthening block can be used to increase the effective value of the length to
diameter ratio or the standard shim can be used to determine the current value.
For workpieces with a length to diameter ratio (L/D) greater than or equal to 15,
(L/D) in the formula is taken as 15.
9.4.2.7 When the workpiece to be tested is too long, segmental magnetization
shall be performed; the effective magnetization range of each magnetization
shall not exceed its effective magnetization area, and there shall be some
overlap, and the length of the overlap area shall not be less than 10 % of the
segmental testing length. During the testing, the magnetizing electric current
shall be determined based on the indication result of the standard shim.
9.4.2.8 When the hollow workpiece is tested, the D of formulas (1) to (3) shall
be replaced by the effective diameter Deff. The effective diameter Deff is.
a) For cylindrical workpieces.
where.
Do - the outer diameter of the cylinder, in millimeters (mm);
Di - the inner diameter of the cylinder, in millimeters (mm).
b) For non-cylindrical workpieces.
9.8 Observation of...