Standard Test Method for Magnetic Particle Examination of Steel Forgings Using Alternating Current

SCOPE
1.1 This test method covers a procedure for the magnetic particle examination of steel forgings using alternating current as the power source. The procedure will produce consistent results upon which acceptance standards can be based. This test method does not contain acceptance limits or recommended quality levels.  
1.2 Only alternating 50-60 cycle current shall be used as the electric power source for any of the magnetizing methods. The ability to detect subsurface discontinuities is very limited when using an alternating power source , and therefore the test surfaces should be in the final thermally treated and finish machined condition.  
1.3 When subsurface indications are sought in forgings, then dc magnetization in accordance with Test Method A 275/A 275M should be used.  
1.4 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text , the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independent of the other. Combining values from the two systems may result in nonconformance with the specification. Unless the order specifies the applicable "M" specification designation [SI units], the inch-pound units shall be used.  
1.5 This standard does not purport to address all of the safety concerns, 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-Sep-1996
Current Stage
Ref Project

Relations

Buy Standard

Standard
ASTM A966/A966M-96 - Standard Test Method for Magnetic Particle Examination of Steel Forgings Using Alternating Current
English language
6 pages
sale 15% off
Preview
sale 15% off
Preview

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NOTICE: This standard has either been superseded and replaced by a new version or
withdrawn.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.
Designation: A 966/A 966M – 96 An American National Standard
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Method for
Magnetic Particle Examination of Steel Forgings Using
1
Alternating Current
This standard is issued under the fixed designation A 966/A 966M; 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.
1. Scope Practice No. SNT-TC-1A, Supplement B—Magnetic Par-
3
ticle Method
1.1 This test method covers a procedure for the magnetic
particle examination of steel forgings using alternating current
3. Terminology
as the power source. The procedure will produce consistent
3.1 Definitions:
results upon which acceptance standards can be based. This test
3.1.1 (ac) magnetic particle method of examination—a
method does not contain acceptance limits or recommended
method for detecting discontinuities on the surface in suitably
quality levels.
magnetized materials, which employs finely divided magnetic
1.2 Only alternating 50–60 cycle current shall be used as the
particles that tend to congregate in regions of leakage fields.
electric power source for any of the magnetizing methods. The
3.1.2 indication—the visual magnetic particle buildup re-
ability to detect subsurface discontinuities is very limited when
sulting from leakage fields in the magnetic field.
using an alternating power source, and therefore the test 3.1.3 linear indication—an indication in which the length is
at least three times the width. The minimum length of
surfaces should be in the final thermally treated and finish
1
indications to be considered linear shall be ⁄16 in. [1.5 mm].
machined condition.
3.1.4 magnetic flux—the product of the magnetic induction
1.3 When subsurface indications are sought in forgings,
and the area of a surface (or cross section) when the magnetic
then dc magnetization in accordance with Test Method A 275/
induction is uniformly distributed and normal to the plane of
A 275M should be used.
the surface. The concept that the magnetic field is flowing
1.4 The values stated in either inch-pound units or SI units
along the lines of force suggests that these lines are therefore
are to regarded separately as standard. Within the text, the SI
“flux” lines, and they are called magnetic flux.
units are shown in brackets. The values stated in each system
3.1.5 nonrelevant indications—indications produced by
are not exact equivalents; therefore each system shall be used
leakage fields where the conditions causing them are present by
independently of the other. Combining values from the two
accident or part design, or other features of the part having no
systems may result in nonconformance with the specification.
relation to the damaging flaws being sought. This term signifies
Unless the order specifies the applicable “M” specification
that such an indication has no relation to the discontinuities that
designation [SI units], the inch-pound units shall be used.
might constitute defects.
1.5 This standard does not purport to address all of the
4. Basis of Application
safety concerns, if any, associated with its use. It is the
4.1 When in accordance with the requirements of the
responsibility of the user of this standard to establish appro-
inquiry, contract, order, or specifications, forgings are to be
priate safety and health practices and determine the applica-
examined by the magnetic particle method using alternating
bility of regulatory limitations prior to use.
current; the manufacturer and the supplier shall be in agree-
ment concerning the following:
2. Referenced Documents
4.1.1 The locations on the forging that are to be subjected to
2.1 ASTM Standards:
magnetic particle examination.
A 275/A 275M Test Method for Magnetic Particle Exami-
4.1.2 The type, size, number, location, and orientation of
2
nation of Steel Forgings
indications that are to be considered injurious.
2.2 Other Document: 4.1.3 The method of application and type of magnetic
particles, demagnetization requirements, and magnetic field
strengths.
1
This test method is under the jurisdiction of ASTM Committee A-1 on Steel,
4.1.4 Acceptance standards.
Stainless Steel, and Related Alloys and is the direct responsibility of Subcommittee
A01.06 on Steel Forgings and Billets.
Current edition approved Sept. 10, 1996. Published December 1996.
3
2
Available from American Society for NonDestructive Testing, 1711 Arlingate
Annual Book of ASTM Standards, Vol 01.05.
Lane, P.O. Box 28518, Columbus, OH 43228-0518.
1

---------------------- Page: 1 ------
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.