ASTM E45-97(2002)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: E 45 – 97 (Reapproved 2002)
Standard Test Methods for
Determining the Inclusion Content of Steel
ThisstandardisissuedunderthefixeddesignationE 45;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscript
epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope A 295 Specification for High-Carbon Anti-Friction Bearing
Steel
1.1 These test methods cover a number of recognized
A 485 Specification for High Hardenability Anti-Friction
methods for determining the nonmetallic inclusion content of
Bearing Steel
wrought steel. Macroscopical methods include macroetch,
A 534 Specification for Carburizing Steels forAnti-Friction
fracture, step-down, and magnetic particle tests. Microscopical
Bearings
methods include five generally accepted systems of examina-
A 535 Specification for Special-Quality Ball and Roller
tion.Inthesemicroscopicalmethods,inclusionsareassignedto
Bearing Steel
a category based on similarities in morphology, and not
A 756 Specification for Stainless Anti-Friction Bearing
necessarily on their chemical identity. Metallographic tech-
Steel
niques that allow simple differentiation between morphologi-
A 866 Specification for Medium Carbon for Anti-Friction
cally similar inclusions are briefly discussed. While the meth-
Bearing Steel
ods are primarily intended for rating inclusions, constituents
D 96 Test Method for Water and Sediment in Crude Oil by
such as carbides, nitrides, carbonitrides, borides, and interme-
Centrifuge Method (Field Procedure)
tallic phases may be rated using some of the microscopical
E 3 Guide for Preparation of Metallographic Specimens
methods. In some cases, alloys other than steels may be rated
E 7 Terminology Relating to Metallography
using one or more of these methods; the methods will be
E 381 Method of Macroetch Testing Steel Bars, Billets,
described in terms of their use on steels.
Blooms, and Forgings
1.2 These test methods are suitable for manual rating of
E 709 Guide for Magnetic Particle Examination
inclusion content. Other ASTM standards cover automatic
E 768 Practice for Preparing and Evaluating Specimens for
methods for obtaining JK ratings (Practice E 1122) and inclu-
Automatic Inclusion Assessment of Steel
sion content using image analysis (Practice E 1245).
E 1122 Practice for Obtaining JK Inclusion Ratings Using
1.3 Depending on the type of steel and the properties
Automatic Image Analysis
required, either a macroscopical or a microscopical method for
E 1245 Practice for Determining Inclusion or Second-Phase
determining the inclusion content, or combinations of the two
Constituent Content of Metals byAutomatic ImageAnaly-
methods, may be found most satisfactory.
sis
1.4 These test methods deal only with recommended test
2.2 SAE Standards:
methods and nothing in them should be construed as defining
J421, Cleanliness Rating of Steels by the Magnetic Particle
or establishing limits of acceptability for any grade of steel.
Method
1.5 This standard does not purport to address all of the
J422, Recommended Practice for Determination of Inclu-
safety concerns, if any, associated with its use. It is the
sions in Steel
responsibility of the user of this standard to establish appro-
2.3 Aerospace Material Specifications:
priate safety and health practices and determine the applica-
2300, Premium Aircraft-Quality Steel Cleanliness: Mag-
bility of regulatory limitations prior to use.
netic Particle Inspection Procedure
2. Referenced Documents 2301, Aircraft Quality Steel Cleanliness: Magnetic Particle
2.1 ASTM Standards:
Annual Book of ASTM Standards, Vol 01.05.
Annual Book of ASTM Standards, Vol 05.01.
1 4
This practice is under the jurisdiction of ASTM Committee E04 on Metallog- Annual Book of ASTM Standards, Vol 03.01.
raphy and is the direct responsibility of Subcommittee E04.09 on Inclusions. Annual Book of ASTM Standards, Vol 03.03.
Current edition approved Apr. 10, 1997. Published June 1997. Originally Available from the Society of Automotive Engineers, 400 Commonwealth
e2
published as E 45 – 42 T. Last previous edition E 45 – 97 . Drive, Warrendale, PA 15096.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E 45 – 97 (2002)
Inspection Procedure 4. Significance and Use
2303, Aircraft Quality Steel Cleanliness: Martensitic
4.1 These test methods cover four macroscopical and five
Corrosion-Resistant Steels Magnetic Particle Inspection
microscopicaltestmethodsfordescribingtheinclusioncontent
Procedure
of steel and procedures for expressing test results.
4.2 Inclusions are characterized by size, shape, concentra-
2304, Special Aircraft-Quality Steel Cleanliness: Magnetic
tion, and distribution rather than chemical composition. Al-
Particle Inspection Procedure
though compositions are not identified, microscopical methods
2.4 ISO Standards:
place inclusions into one of several composition-related cat-
ISO 3763, Wrought steels—Macroscopic methods for as-
egories (sulfides, oxides, and silicates—the last as a type of
sessing the content of nonmetallic inclusions
oxide). Paragraph 12.2.6 describes a metallographic technique
ISO 4967, Steel—Determination of content of nonmetallic
to facilitate inclusion discrimination. Only those inclusions
inclusions—Micrographic methods using standard dia-
present at the test surface can be detected.
grams
4.3 The macroscopical test methods evaluate larger surface
2.5 ASTM Adjuncts:
areas than microscopical test methods and because examina-
Inclusions in Steel Plates I-r and II
tion is visual or at low magnifications, these methods are best
Four Photomicrographs of Low Carbon Steel
suited for detecting larger inclusions. Macroscopical methods
arenotsuitablefordetectinginclusionssmallerthanabout0.40
3. Terminology 1
mm ( ⁄64 in.) in length and the methods do not discriminate
inclusions by type.
3.1 Definitions:
4.4 The microscopical test methods are employed to char-
3.1.1 For definitions of terms used in this practice, see
acterize inclusions that form as a result of deoxidation or due
TerminologyE7.
to limited solubility in solid steel (indigenous inclusions).
3.1.2 Terminology E7 includes the term inclusion count;
These inclusions are characterized by morphological type, that
since some methods of these test methods involve length
is, by size, shape, concentration, and distribution, but not
measurements or conversions to numerical representations of
specifically by composition. The microscopical methods are
lengths or counts, or both, the term inclusion rating is
not intended for assessing the content of exogenous inclusions
preferred.
3.2 Definitions of Terms Specific to This Standard: (those from entrapped slag or refractories) nor for rating the
content of carbides, carbonitrides, nitrides, borides, or inter-
3.2.1 aspect ratio—the length-to-width ratio of a micro-
structural feature. metallic phases, although they are sometimes used for this
latter purpose.
3.2.2 discontinuous stringer—three or more Type B or C
inclusions aligned in a plane parallel to the hot working axis 4.5 Because the inclusion population within a given lot of
steel varies with position, the lot must be statistically sampled
andoffsetbynomorethan15µm,withaseparationoflessthan
40 µm (0.0016 in.) between any two nearest neighbor inclu- in order to assess its inclusion content. The degree of sampling
mustbeadequateforthelotsizeanditsspecificcharacteristics.
sions.
Materials with very low inclusion contents may be more
3.2.3 inclusion types—for definitions of sulfide-, alumina-,
accurately rated by automatic image analysis (see Practice
and silicate-type inclusions, see Terminology E7. Globular
E 1122), which permits more precise microscopical ratings.
oxide, in some methods refers to isolated, relatively nonde-
4.6 Results of macroscopical and microscopical test meth-
formed inclusions with an aspect ratio not in excess of 5:1. In
ods may be used to qualify material for shipment, but these test
other methods, oxides are divided into deformable and nonde-
methods do not provide guidelines for acceptance or rejection
formable types.
purposes. Qualification criteria for assessing the data devel-
3.2.4 JK inclusion rating—a method of measuring nonme-
oped by these methods can be found in ASTM product
tallicinclusionsbasedontheSwedishJernkontoretprocedures;
standards or may be described by purchaser-producer agree-
Methods A and D of these test methods are the principal JK
ments.
rating methods, and Method E also uses the JK rating charts.
4.7 These test methods are intended for use on wrought
3.2.5 stringer—an individual inclusion that is highly elon-
gated in the deformation direction or three or more Type B or metallic structures. While a minimum level of deformation is
not specified, the test methods are not suitable for use on cast
C inclusions aligned in a plane parallel to the hot working axis
andoffsetbynomorethan15µm,withaseparationoflessthan structures or on lightly worked structures.
40 µm (0.0016 in.) between any two nearest neighbor inclu-
MACROSCOPICAL METHODS
sions.
3.2.6 worst-field rating—a rating in which the specimen is
5. Macroscopical Test Methods Overview
rated for each type of inclusion by assigning the value for the
5.1 Summary:
highest severity rating observed of that inclusion type any-
5.1.1 Macroetch Test—The macroetch test is used to indi-
where on the specimen surface.
cate inclusion content and distribution, usually in the cross
section or transverse to the direction of rolling or forging. In
some instances, longitudinal sections are also examined. Tests
are prepared by cutting and machining a section through the
Available from ASTM Headquarters. Order ADJE004502.
Available from ASTM Headquarters. Order ADJE004501. desired area and etching with a suitable reagent. A solution of
E 45 – 97 (2002)
one part hydrochloric acid and one part water at a temperature 5.3.2 They are not suitable for the detection of small
of 71 to 82°C (160 to 180°F) is widely used. As the name of globular inclusions or of chains of very fine elongated inclu-
this test implies, the etched surface is examined visually or at
sions.
low magnification for inclusions. Details of this test are
5.3.3 The magnetic particle method can lead to incorrect
included in Method E 381. The nature of questionable indica-
interpretation of microstructural features such as streaks of
tions should be verified by microscopical or other means of
retained austenite, microsegregation, or carbides in certain
inspection.
alloys; this is particularly likely if high magnetization currents
5.1.1.1 Sulfides are revealed as pits when the standard
are employed.
etchant described in 5.1.1 is used.
5.1.1.2 Only large oxides are revealed by this test method. 6. Magnetic Particle Method—Details of Procedure
5.1.2 Fracture Test—The fracture test is used to determine
6.1 Test Specimens:
the presence and location of inclusions as shown on the
6.1.1 The specimens shall be prepared in accordance with
3 1
fracture of hardened slices approximately 9 to 13 mm ( ⁄8 to ⁄2
the details given in 6.2. The recommended procedure for
in.) thick.This test is used mostly for steels where it is possible
removal from blooms, billets, and bars in round or square
to obtain a hardness of approximately 60 HRC and a fracture
sections is as follows:
grain size of 7 or finer. Test specimens should not have
2 2
6.1.1.1 CrossSectionsover230cm (36in. )—Cutaquarter
excessive external indentations or notches that guide the
section as shown in Fig. 1 or 2 and prepare the specimen by
fracture. It is desirable that fracture be in the longitudinal
machining, or forging and machining, to a straight cylinder of
direction approximately across the center of the slice. The
a diameter between 60 and 150 mm (2 ⁄2 and 6 in.). An
fractured surfaces are examined visually and at magnifications
alternative method is to forge or roll the full section to 150 mm
up to approximately ten diameters, and the length and distri-
(6 in.) square or round and machine the quarter section in
bution of inclusions is noted. Heat tinting, or blueing, will
accordance with 6.1.1.2.
increasevisibilityofoxidestringers.ISO3763providesachart
2 2
method for fracture surface inclusion ratings. In some in-
6.1.1.2 Cross Sections 100 to 230 cm (16 to 36 in. )
stances, indications as small as 0.40 mm ( ⁄64 in.) in length are
Inclusive—Cut a quarter section as shown in Fig. 1 or Fig. 2
recorded.
and prepare the specimen by machining, or forging and
5.1.3 Step-Down Method—The step-down test method is machining, to a straight cylinder of the largest possible
used to determine the presence of inclusions on machined
diameter.
2 2
surfaces of rolled or forged steel. The test sample is machined
6.1.1.3 Cross Sections Less than 100 cm (16 in. )—
to specified diameters below the surface and surveyed for
Machine the specimen to a straight cylinder. An alternative
inclusions under good illumination with the unaided eye or
method is to use a three diameter step-down specimen, each
with low magnification. In some instances, test samples are
cylindricalsectionbeing75mm(3in.)inlength.Thediameter,
machinedtosmallerdiametersforfurtherexaminationafterthe
D, of the first step is the stock size less standard machining
original diameters are inspected. This test is essentially used to
allowance; the diameter of the second step is ⁄4 D; and the
determine the presence of inclusions 3 mm ( ⁄8 in.) in length
diameter of the third step is ⁄2 D.
and longer.
6.1.2 The specimens shall conform to the following require-
5.1.4 Magnetic Particle Method—The magnetic particle
ments unless specified otherwise in 6.1.1.1-6.1.1.3:
method is a variation of the step-down method for ferromag-
6.1.2.1 The length of the rated surface is nominally 125 mm
netic materials in which the test sample is machined, magne-
(5 in.). A 25 mm (1 in.) extension for holding is usually
tized, and magnetic powder is applied. Discontinuities as small
employed.
as 0.40 mm ( ⁄64 in.) in length create magnetic leakage fields
6.1.2.2 The minimum amount of stock removed from the
that attract the magnetic powder, thereby outlining the inclu-
surface shall be as follows:
sion. See Section 6 for a detailed procedure.
5.2 Advantages:
5.2.1 These test methods facilitate the examination of speci-
mens with large surface areas. The larger inclusions in steel,
which are the main concern in most cases, are not uniform
...