ASTM E571-98(2003)e1

Standard Practice for Electromagnetic (Eddy-Current) Examination of Nickel and Nickel Alloy Tubular Products

SIGNIFICANCE AND USE
Eddy-current examination is a nondestructive method of locating discontinuities in metallic materials. Signals can be produced by discontinuities originating on either the external or internal surfaces of the tube or by discontinuities totally contained within the wall. Since the density of eddy currents decreases nearly exponentially with increasing distance from the surface nearest the coil, the response to deep-seated defects decreases correspondingly. Phase changes are also associated with changes in depth, allowing the use of phase analysis techniques.
The response from natural discontinuities can be significantly different than that from artificial discontinuities, such as drilled holes or notches. For this reason, sufficient work should be done to establish the sensitivity level and setup required to detect natural discontinuities of consequence to the end use of the product.
Some indications obtained by this method may not be relevant to product quality; for example, an irrelevant indication may be caused by minute dents or tool chatter marks, which are not detrimental to the end use of the product. Irrelevant indications can mask unacceptable discontinuities. Relevant indications are those which result from discontinuities. Any indication that exceeds the rejection level shall be treated as a relevant indication until it can be demonstrated that it is irrelevant.
Generally, eddy-current examination systems are not sensitive to discontinuities adjacent to the ends of the tube (end effect).
Discontinuities such as scratches or seams that are continuous and uniform over the full length of the tube may not always be detected with differential encircling coils or probes scanned along the tube length.
For material that is magnetic, a strong magnetic field shall be placed in the region of the examining coil. A magnetic field may also be used to improve the signal-to-noise ratio in tubing that exhibits slight residual magnetism.
SCOPE
1.1 This practice covers the procedures for eddy-current testing of nickel and nickel alloy tubes. These procedures are applicable for tubes with outside diameters up to 2 in. (50.8 mm), incl, and wall thicknesses from 0.035 to 0.120 in. (0.889 to 3.04 mm), incl. These procedures may be used for tubes beyond the size range recommended, by contractual agreement between the purchaser and the producer.  
1.2 The procedures described in this practice make use of fixed encircling test coils or probe systems.
1.3 The values stated in inch-pound units are to be regarded as the standard.
Note 1-- For convenience, the term "tube" or "tubular product" will hereinafter be used to refer to both pipe and tubing.
1.4  This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 09-Jul-2003
• Technical Committee: E07 - Nondestructive Testing
• Drafting Committee: E07.07 - Electromagnetic Method

Relations

• Replaces: ASTM E571-98 - Standard Practice for Electromagnetic (Eddy-Current) Examination of Nickel and Nickel Alloy Tubular Products
• Effective Date: 10-Jul-2003
• Replaced By: ASTM E571-98(2007)e1 - Standard Practice for Electromagnetic (Eddy-Current) Examination of Nickel and Nickel Alloy Tubular Products
• Effective Date: 01-Dec-2007
• Referred By: ASTM E543-21 - Standard Specification for Agencies Performing Nondestructive Testing
• Effective Date: 10-Jul-2003
• Referred By: ASTM B775/B775M-22 - Standard Specification for General Requirements for Nickel and Nickel Alloy Welded Pipe
• Effective Date: 10-Jul-2003
• Referred By: ASTM B829-19a - Standard Specification for General Requirements for Nickel and Nickel Alloys Seamless Pipe and Tube
• Effective Date: 10-Jul-2003
• Referred By: ASTM B924-02(2022) - Standard Specification for Seamless and Welded Nickel Alloy Condenser and Heat Exchanger Tubes With Integral Fins
• Effective Date: 10-Jul-2003
• Referred By: ASTM B725-22 - Standard Specification for Welded Nickel and Nickel Copper Alloy Pipe
• Effective Date: 10-Jul-2003
• Referred By: ASTM B751-21 - Standard Specification for General Requirements for Nickel and Nickel Alloy Welded Tube
• Effective Date: 10-Jul-2003
• Referred By: ASTM B1015-20 - Standard Practice for Form and Style of Standards Relating to Refined Nickel and Cobalt and Their Alloys
• Effective Date: 10-Jul-2003
• Referred By: ASTM E3166-20e1 - Standard Guide for Nondestructive Examination of Metal Additively Manufactured Aerospace Parts After Build
• Effective Date: 10-Jul-2003

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
e1
Designation: E 571 – 98 (Reapproved 2003)
Standard Practice for
Electromagnetic (Eddy-Current) Examination of Nickel and
Nickel Alloy Tubular Products
This standard is issued under the fixed designation E 571; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
e NOTE—Editorial changes made throughout the standard in July 2003.
1. Scope Certification of Nondestructive Testing Personnel
2 NAS-410 Certification and Qualification of Nondestructive
1.1 This practice covers the procedures for eddy-current
Personnel (Quality Assurance Committee)
examination of nickel and nickel alloy tubes.These procedures
are applicable for tubes with outside diameters up to 2 in. (50.8
3. Terminology
mm), incl, and wall thicknesses from 0.035 to 0.120 in. (0.889
3.1 Standard terminology relating to electromagnetic ex-
to 3.04 mm), incl. These procedures may be used for tubes
amination may be found in Terminology E 1316, Section C,
beyond the size range recommended, by contractual agreement
Electromagnetic Testing.
between the purchaser and the producer.
1.2 The procedures described in this practice make use of
4. Summary of Practice
fixed encircling coils or probe systems.
4.1 Examination is usually performed by the use of one of
1.3 The values stated in inch-pound units are to be regarded
two general techniques:
as the standard.
4.1.1 Encircling Coil Technique—Examination is per-
NOTE 1—For convenience, the term “tube” or “tubular product” will
formed by passing the tube lengthwise through a coil energized
hereinafter be used to refer to both pipe and tubing.
with alternating current at one or more frequencies. See Fig. 1.
1.4 This standard does not purport to address all of the The electrical impedance of the coil is modified by the
safety concerns, if any, associated with its use. It is the
proximity of the tube, the tube dimensions, electrical conduc-
responsibility of the user of this standard to establish appro- tivity, saturating magnetic field, magnetic permeability, and
priate safety and health practices and determine the applica-
metallurgical or mechanical discontinuities in the tube. As the
bility of regulatory limitations prior to use. tube passes through the coil, the changes in electromagnetic
response caused by these variables in the tube change the coil
2. Referenced Documents
impedance, which activates an audible or visual signaling
2.1 ASTM Standards:
device or a mechanical marker.
E 309 Practice for Eddy-Current Examination of Steel Tu-
4.1.2 Probe Coil Technique—Probe coils are positioned in
bular Products Using Magnetic Saturation
close proximity to the outside diameter or to the inside
E 543 Practice for Agencies Performing Nondestructive
diameter, or to both diameter surfaces, of the tubular product
Testing
beingexaminedasshowninFig.1.Sincetheprobeisgenerally
E 1316 Terminology for Nondestructive Examinations
small and does not encircle the tube, it examines only a limited
2.2 Other Documents:
area in the vicinity of the probe. When required to examine the
SNT-TC-1A Recommended Practice for Personnel Qualifi-
entire volume of the tubular product, it is common practice to
cation and Certification in Nondestructive Testing
rotate either the tubular product or the probe around the tube.
ANSI/ASNT-CP-189 ASNT Standard for Qualification and
Frequently, in the case of welded tubular products, only the
weld is examined by scanning along the weld zone.
4.2 The magnetic permeability of magnetic materials se-
This practice is under the jurisdiction of ASTM Committee E07 on Nonde-
verely limits the depth of penetration of induced eddy currents.
structive Testing and is the direct responsibility of Subcommittee E07.07 on
Furthermore, the permeability variations inherent in magnetic
Electromagnetic Methods.
tubular products can cause spurious test results. A useful
Current edition approved July 10, 2003. Published September 2003. Originally
approved in 1976. Last previous edition approved in 1998 as E 571 - 98.
solution to this problem involves the application of a strong
For ASME Boiler and Pressure Vessel Code applications see related Practice
SE-571 in Section II of that Code.
Annual Book of ASTM Standards, Vol 03.03.
4 5
Available fromTheAmerican Society for NondestructiveTesting (ASNT), P.O. Available from Aerospace Industries Association of America, Inc., 1250 Eye
Box 28518, 1711 Arlingate Lane, Columbus, OH 43228-0518. Street, N.W., Washington, DC 20005.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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E 571 – 98 (2003)
decreases correspondingly. Phase changes are also associated
with changes in depth, allowing the use of phase analysis
techniques.
5.2 The response from natural discontinuities can be signifi-
cantly different than that from artificial discontinuities, such as
drilled holes or notches. For this reason, sufficient work should
be done to establish the sensitivity level and setup required to
detect natural discontinuities of consequence to the end use of
the product.
5.3 Some indications obtained by this method may not be
relevant to product quality; for example, an irrelevant indica-
tion may be caused by minute dents or tool chatter marks,
which are not detrimental to the end use of the product.
Irrelevant indications can mask unacceptable discontinuities.
Relevant indications are those which result from discontinui-
ties. Any indication that exceeds the rejection level shall be
treated as a relevant indication until it can be demonstrated that
it is irrelevant.
5.4 Generally, eddy-current examination systems are not
sensitive to discontinuities adjacent to the ends of the tube (end
effect).
5.5 Discontinuities such as scratches or seams that are
continuousanduniformoverthefulllengthofthetubemaynot
always be detected with differential encircling coils or probes
scanned along the tube length.
5.6 For material that is magnetic, a strong magnetic field
shall be placed in the region of the examining coil.Amagnetic
field may also be used to improve the signal-to-noise ratio in
tubing that exhibits slight residual magnetism.
FIG. 1 Encircling-Coil and Probe-Coil Techniques for
6. Basis of Application
Electromagnetic Examination of Tubular Products
6.1 The following criteria may be specified in the purchase
specification contractual agreement, or elsewhere, and may
external magnetic field in the region of the examining coil or
require agreement between the purchaser and the supplier.
probe. This technique, known as magnetic saturation, causes a
6.1.1 Acceptance criteria.
magnetic material to exhibit sufficiently small magnetic char-
6.1.2 Type, dimensions, and number of artificial disconti-
acteristics of permeability, hysteresis, etc., so that the material
nuities to be placed in the reference standard.
under examination is effectively rendered nonmagnetic. When
6.1.3 Extent of examination; that is, full circumference of
achieved, this condition allows an eddy-current system to
outside or inside diameter, or both, or weld only, if welded.
measure and detect electrical resistivity and geometrical varia-
6.1.4 Operator qualifications, if required (see 6.1.6 below).
tions (including defects) independent of concurrent variations
6.1.5 Standardization intervals.
in magnetic properties.
6.1.6 If specified in the contractual agreement, personnel
NOTE 2—Practice E 309 may be used for strongly magnetic materials.
performing examinations to this practice shall be qualified in
4.2.1 During the examination of slightly magnetic tubing
accordance with a nationally recognized NDT personnel quali-
the signals resulting from the variation of magnetic permeabil-
fication practice or standard such as ANSI/ASNT-CP-189,
ity can mask the signals resulting from small imperfections. A
SNT-TC-1A, NAS-410, ASNT-ACCP, or a similar document
magnetic saturation technique can be used to reduce this
and certified by the certifying agency as applicable. The
interference to an acceptable level.
practice or standard used and its applicable revision shall be
identified in the contractual agreement between the using
5. Significance and Use
parties.
5.1 Eddy-current examination is a nondestructive method of
NOTE 3—MIL-STD-410 is canceled and has been replaced with NAS-
locating discontinuities in metallic materials. Signals can be
410, however, it may be used with agreement between contracting parties.
produced by discontinuities originating on either the external
or internal surfaces of the tube or by discontinuities totally 6.1.7 If specified in the contractual agreement, NDT agen-
contained within the wall. Since the density of eddy currents cies shall be qualified and evaluated in accordance with
decreases nearly exponentially with increasing distance from Practice E 543. The applicable edition of Practice E 543 shall
the surface nearest the coil, the response to deep-seated defects be specified in the contractual agreement.
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E 571 – 98 (2003)
7. Apparatus 8.1.1 Notch—Longitudinal or transverse notches, or both,
may be produced by milling, filing, EDM (Electric Discharge
7.1 Electronic Apparatus—The electronic apparatus shall
Machine) or other suitable means. Notches may be placed on
be capable of energizing the encircling coils or probes with
the outer, inner, or both surfaces of the reference standard.
alternating current of suitable frequencies and shall be capable
of sensing changes in impedance of the encircling coils or
NOTE 4—Longitudinal notch standards are normally used when exam-
probes. Equipment may include any appropriate signal pro- ining with rotating probe systems.
cessing circuits such as a phase discriminator, filter circuits,
8.1.2 Hole—The holes shall be drilled radially partially or
etc., as req
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