Standard Test Method for X-Ray Emission Spectrometric Analysis of Low-Alloy Steels

SIGNIFICANCE AND USE
This procedure is suitable for manufacturing control and for verifying that the product meets specifications. This test method provides rapid, multielement determinations with sufficient accuracy to ensure product quality and minimize production delays. The analytical performance data may be used as a benchmark to determine if similar X-ray spectrometers provide equivalent precision and accuracy, or if the performance of a particular X-ray spectrometer has changed.
Calcium is sometimes added to steel to effect inclusion shape control in order to enhance certain mechanical properties of steel. This test method is useful for determining the residual calcium in the steel after such treatment.
5.2.1 Because calcium occurs primarily in inclusions, the precision of this test method is a function of the distribution of the calcium-bearing inclusions in the steel. The variation of determinations on freshly prepared surfaces will give some indication of the distribution of these inclusions.
SCOPE
1.1 This test method covers the wavelength dispersive X-ray spectrometric analysis of low-alloy steels for the following elements:ElementConcentration Range, %Nickel 0.04 to 3.0Chromium0.04 to 2.5Manganese0.04 to 2.5Silicon 0.06 to 1.5Molybdenum0.005 to 1.5Copper 0.03 to 0.6Vanadium0.012 to 0.6Cobalt 0.03 to 0.2Sulfur 0.009 to 0.1Niobium 0.002 to 0.1Phosphorus0.010 to 0.08Calcium 0.001 to 0.007
1.2 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. Specific precautionary statements are given in Section 10.

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ASTM E1085-95(2004) - Standard Test Method for X-Ray Emission Spectrometric Analysis of Low-Alloy Steels
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:E1085–95 (Reapproved 2004)
Standard Test Method for
X-Ray Emission Spectrometric Analysis of Low-Alloy
Steels
This standard is issued under the fixed designation E 1085; 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 E 1622 Practice for the Correction of Spectral Line Overlap
in Wavelength X-Ray Spectrometry
1.1 This test method covers the wavelength dispersive
X-ray spectrometric analysis of low-alloy steels for the follow-
3. Terminology
ing elements:
3.1 For definitions of terms used in this test method, refer to
Element Concentration Range, %
Terminology E 135.
Nickel 0.04 to 3.0
Chromium 0.04 to 2.5
Manganese 0.04 to 2.5 4. Summary of Test Method
Silicon 0.06 to 1.5
4.1 The test specimen is finished to a clean uniform surface
Molybdenum 0.005 to 1.5
Copper 0.03 to 0.6
and then irradiated with an X-ray beam of high energy. The
Vanadium 0.012 to 0.6
secondary X rays produced are dispersed by means of crystals,
Cobalt 0.03 to 0.2
and the intensities are measured by suitable detectors at
Sulfur 0.009 to 0.1
Niobium 0.002 to 0.1
selected wavelengths. Radiation measurements are made based
Phosphorus 0.010 to 0.08
on the time required to reach a fixed number of counts, or on
Calcium 0.001 to 0.007
thetotalcountsobtainedforafixedtime.Concentrationsofthe
1.2 This standard does not purport to address all of the
elements are determined by relating the measured radiation of
safety concerns, if any, associated with its use. It is the
unknownspecimenstoanalyticalcurvespreparedwithsuitable
responsibility of the user of this standard to establish appro-
reference materials. Either a fixed-channel, polychromator
priate safety and health practices and determine the applica-
system or a sequential, monochromator system may be used to
bility of regulatory limitations prior to use. Specific precau-
providesimultaneousorsequentialdeterminationsofelements.
tionary statements are given in Section 10.
5. Significance and Use
2. Referenced Documents
5.1 Thisprocedureissuitableformanufacturingcontroland
2.1 ASTM Standards:
for verifying that the product meets specifications. This test
E 135 Terminology Relating to Analytical Chemistry for
method provides rapid, multielement determinations with suf-
Metals, Ores, and Related Materials
ficient accuracy to ensure product quality and minimize pro-
E 305 Practice for Establishing and Controlling Spectro-
duction delays. The analytical performance data may be used
chemical Analytical Curves
as a benchmark to determine if similar X-ray spectrometers
E 691 Practice for Conducting an Interlaboratory Study to
provide equivalent precision and accuracy, or if the perfor-
Determine the Precision of a Test Method
mance of a particular X-ray spectrometer has changed.
E 1361 Guide for Correction of Interelement Effects in
5.2 Calcium is sometimes added to steel to effect inclusion
X-Ray Spectrometric Analysis
shapecontrolinordertoenhancecertainmechanicalproperties
of steel. This test method is useful for determining the residual
1 calcium in the steel after such treatment.
This test method is under the jurisdiction of ASTM Committee E01 on
Analytical Chemistry of Metals, Ores, and Related Materials and is the direct 5.2.1 Because calcium occurs primarily in inclusions, the
responsibility of Subcommittee E01.01 on Iron, Steel, and Ferroalloys.
precision of this test method is a function of the distribution of
Current edition approved Oct. 1, 2004. Published November 2000. Originally
the calcium-bearing inclusions in the steel. The variation of
approved in 1987. Last previous edition approved in 2000 as E 1085 – 95 (2000).
determinations on freshly prepared surfaces will give some
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
indication of the distribution of these inclusions.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E1085–95 (2004)
6. Interferences 7.4 Measuring System, consisting of electronic circuits ca-
pable of amplifying and integrating pulses received from the
6.1 Interelement or matrix effects may exist for some of the
detectors. For some measurements, pulse height analyzers may
elementsin1.1.Mathematicalcorrectionsmaybeusedtosolve
be required to provide more accurate measurements. The
for these effects. Various mathematical correction procedures
system shall be equipped with an appropriate recording device.
arecommonlyutilized.SeeGuideE 1361andPracticeE 1622.
Any of these procedures is acceptable that will achieve
8. Reagents and Materials
analytical accuracy equivalent to that provided by this test
8.1 Detector Gas (P-10), consisting of a mixture of 90 %
method.
argon and 10 % methane, for use with gas-flow proportional
6.2 Because trace amounts of calcium are being determined
counters only.
with this test method, exercise care not to contaminate the
specimen. The presence of calcium in the grinding medium
9. Reference Materials
will contaminate the specimen to the extent that erratic and
9.1 Certified Reference Materials are available from the
incorrect results will be obtained. Therefore, the grinding
National Institute of Standards and Technology and other
medium shall be analyzed for calcium and only those materials
international certification agencies.
that are free of calcium shall be used.
9.2 Reference Materials with matrices similar to that of the
test specimen and containing varying amounts of the elements
7. Apparatus
to be determined may be used provided they have been
7.1 Specimen Preparation Equipment:
chemically analyzed in accordance with ASTM standard test
7.1.1 Surface Grinder or Sander WithAbrasive Belts, Disks,
methods.These reference materials shall be homogeneous, and
or Lathe, capable of providing a flat, uniform surface on the
free of voids or porosity.
reference materials and test specimens.
9.3 The reference materials shall cover the concentration
7.1.1.1 When calcium is to be determined, 240-grit,
ranges of the elements being sought. A minimum of three
calcium-free silicon carbide belts or disks shall be used.
reference materials shall be used for each element.
7.2 Excitation Source:
7.2.1 X-Ray Tube Power Supply, providing a constant po- 10. Hazards
tential or rectified power of sufficient energy to produce
10.1 Occupational Health and Safety standards for ionizing
secondary radiation of the specimen for the elements specified.
radiation shall be observed at all X-ray emission spectrometer
The generator may be equipped with a line voltage regulator
installations. It is also recommended that operating and main-
and current stabilizer.
tenance personnel follow the guidelines of safe operating
7.2.2 X-Ray Tubes, with targets of various high-purity
procedures given in current handbooks and publications from
5,6
elements, that are capable of continuous operation at required
the National Institute of Standards and Technology and the
potentials and currents, and will excite the elements to be
U.S. Government Printing Office, or similar handbooks on
determined.
radiation safety.
7.2.2.1 For the determination of calcium only chromium 10.2 X-rayequipmentshallbeusedonlyundertheguidance
target tubes were tested. Other targets shall be tested prior to
and supervision of a responsible, qualified person.
use. 10.3 Monitoring Devices, either film badges or dosimeters
7.3 Spectrometer,designedforX-rayemissionanalysis,and may be worn by all operating and maintenance personnel.
Safety regulations shall conform to applicable local, state, and
equipped with specimen holders and a specimen chamber. The
chamber may contain a specimen spinner, and must be federal regulations. To meet local, state, and federal radiation
standards,periodicradiationsurveysoftheequipmentforleaks
equipped for vacuum or helium-flushed operation for the
determination of elements of Atomic Number 20 (calcium) or and excessive scattered radiation shall be made by a qualified
person using an ionization-chamber detector.The personal film
lower.
badge survey record, the radiation survey record, and an
7.3.1 Analyzing Crystals, flat or curved crystals with opti-
equipment maintenance record shall be available upon request.
mized capability for the diffraction of the wavelengths of
interest.
7.3.2 Collimator, for limiting the characteristic X rays to a
parallel bundle when flat crystals are used in the instrument. Office of Standard Reference Materials, National Institute of Standards and
Technology, U.S. Department of Commerce, Gaithersburg, MD 20899.
For curved crystal optics, a collimator is not necessary.
ANSI/NBS Handbook 114, General Safety Standard for Installations Using
7.3.3 Detectors, sealed or gas-flow proportional-type, scin-
Non-Medical X-Ray and Sealed Gamma-Ram Sources, available from American
tillation counters, or equivalent. National Standards Institute, 11 W. 42nd St., 13th Floor, New York, NY 10036.
NBS Handbook 76, Medical X-Ray Protection Up to Three Million Volts,
7.3.4 Vacuum System, providing for the determination of
available as NCRP 33 from NCRP Publications, 7910 WoodmontAve., Suite 1016,
elements whose radiation is absorbed by air (for example,
Bethesda, MD 20814.
calcium, silicon, phosphorus, and sulfur). The system shall
ANSI N43.2-1977/NBS Handbook 111, Radiation Safety for X-Ray Diffraction
and Fluorescence Analysis, available from American National Standards Institute,
consist of a vacuum pump, gage, and electrical controls to
11 W. 42nd St., 13th Floor, New York, NY 10036.
provide automatic pumpdown of the optical path and maintain
Moore, T. M., and McDonald, D. J., Radiation Safety Recommendations for
a controlled pressure, usually 13 Pa (100 µm Hg) or less,
X-Ray Diffraction and Spectrographic Equipment, MORP 68-14, 1968, available
controlled to 63Pa(620 µm Hg). from National Technical Information Service, Springfield, VA 22161.
E1085–95 (2004)
10.4 Special precautions for operators and maintenance by the variation in the counting statistics. A minimum of
personnel shall be posted at the equipment site. 10 000 counts is required for 1 % precision of the counting
10.5 Radiation caution signs shall be posted near the X-ray statistics and 40 000 for 0.5 %.
equipment and at all entrances to the radiation area, consistent
13. Calibration and Standardization
with state and federal regulations.
13.1 Calibration (Preparation of Analytical Curves)—
10.6 Fail-safe “X-Ray On” warning lights shall be used on
the equipment. Using the conditions given in Section 12, measure a series of
reference materials that cover the required concentration
11. Preparation of Reference Materials and Test
ranges. Use at least three reference materials for each element.
Specimens
Measure the reference materials at least two different times on
11.1 Prepare the reference materials and test specimens to each of two separate days. Prepare an analytical curve for each
element being determined (refer to Practice E 305).
provideaclean,flatuniformsurfacetobeexposedtotheX-ray
beam. For abrasive sanding, select a grit size, and use that grit 13.2 Standardization (Analytical Curve Adjustment)—
Using a control reference material, check the calibration of the
and size exclusively for all reference materials and test
X-ray spectrometer at a frequency consistent with statistical
specimens.
11.2 Refinish the surface of the reference materials and test process control practice, or when the detector gas or major
components have been changed. If the calibration check
specimens as needed to eliminate surface contamination.
indicates that the spectrometer has drifted, make appropriate
12. Preparation of Apparatus
adjustments in accordance with the instructions in the manu-
12.1 Prepare and operate the spectrometer in accordance facturer’s manual. Refer to Practice E 305 for frequency of
verification of standardization.
with the manufacturer’s instructions.
NOTE 1—It is not within the scope of this test method to prescribe
14. Procedure
minute details relative to the preparation of the apparatus. For a descrip-
14.1 Specimen Loading—Orient the reference materials and
tion and specific details concerning the operation of a particular spectrom-
testspecimensinthespecimenchambersothattherelationship
eter, refer to the manufacturer’s manual.
between the X-ray beam and the grinding striations is the same
12.1.1 Start-up—Turn on the power supply and electronic
for all measurements. This is an essential requirement if the
circuits and allow sufficient time for instrument warm-up prior
spectrometer is not equipped with a specimen spinner, but is
to taking measurements.
not necessary when a spinner is used.
12.2 Tube Power Supply—Adjust the voltage of the power
14.2 Excitation—Expose the specimen to primary X radia-
supply to produce optimum conditions.
tion in accordance with Section 12.
12.2.1 The voltage and current established as optimum for
14.3 Radiation Measurements—Obtain and record the
the X-ray emission power supply in an individual laboratory
countingratemeasurementforeachelement.Eitherfixedcount
shall be reproduced for subsequent measurements.
or fixed time modes may be used. Obtain at least the prede-
12.3 Proportional Counter Gas Flow— When a gas-flow
termined minimum counts for all specimens.
proportional counter is used, adjust flow of the P-10 gas in
14.4 Spectral Interferences—Some X-ray spectrometers
accordance with the equipment manufacturer’s instructions.
will not completely resolve radiation from several elemental
When changing P-10 tanks, the detectors should be adequately
combinations (for example, molybdenum and sulfur; molyb-
flushed with detector gas and adjusted before the instrument is
denum and phosphorus; iron and cobalt). Therefore, exercise
used.
care in the interpretation of intensities when both elements are
12.4 Measurement Conditions—The K-a lines for each
present. Use mathematical calculations to correct for such
element are used. The peak location, when using a scanning
interferences. See Practice E 1622.
spectrometer, should be determined for each instrument.
14.5 Replicate Measurements—Make a single measurement
12.4.1 Crystals and Detectors—The following crystals and
on each test specimen.The performance of an X-ray spectrom-
detectors are used for the elements indicated:
eter is not improved
...

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