ASTM E572-21

Standard Test Method for Analysis of Stainless and Alloy Steels by Wavelength Dispersive X-Ray Fluorescence Spectrometry

SIGNIFICANCE AND USE
5.1 This procedure is suitable for manufacturing control and for verifying that the product meets specifications. It provides rapid, multi-element determinations with sufficient accuracy to assure product quality. The analytical performance data included 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 spectrometer has changed.  
5.2 It is expected that this standard will be employed by analysts knowledgeable in the field of X-ray fluorescence spectrometry and experienced in the use of the apparatus specified in this test method.
SCOPE
1.1 This test method2 covers the analysis of stainless and alloy steels by wavelength dispersive X-ray Fluorescence Spectrometry for the determination of the following elements:    
Element  
Range, Mass Fraction %  
Chromium  
0.5 to 25  
Cobalt  
0.05 to 0.45  
Copper  
0.06 to 3.5    
Manganese  
0.3 to 5.5  
Molybdenum  
0.02 to 3.5    
Nickel  
0.6 to 35    
Niobium  
0.03 to 1.3    
Phosphorus  
0.01 to 0.03  
Silicon  
0.1 to 2    
Sulfur  
0.02 to 0.35  
Titanium  
0.008 to 0.5    
Vanadium  
0.02 to 0.25
Note 1: Unless exceptions are noted, mass fraction ranges can be extended by using suitable reference materials. Extended ranges must be verified by experimental means. This could include, but not be limited to, Interlaboratory studies, Round Robin exercises, and other validation approaches. See Guide E2857 for additional guidance.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in Section 10.  
1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 14-May-2021
• ICS: 77.140.20 - Stainless steels
• Technical Committee: E01 - Analytical Chemistry for Metals, Ores, and Related Materials
• Drafting Committee: E01.01 - Iron, Steel, and Ferroalloys

Relations

• Refers: ASTM E135-20 - Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• Effective Date: 01-Jan-2020
• Refers: ASTM E135-19 - Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• Effective Date: 15-May-2019
• Refers: ASTM E135-16 - Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• Effective Date: 15-May-2016
• Refers: ASTM E135-15a - Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• Effective Date: 01-Jul-2015
• Refers: ASTM E135-15 - Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• Effective Date: 15-May-2015
• Refers: ASTM E135-14b - Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• Effective Date: 15-Aug-2014
• Refers: ASTM E177-14 - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 01-May-2014
• Refers: ASTM E135-14a - Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• Effective Date: 01-Apr-2014
• Refers: ASTM E135-14 - Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• Effective Date: 15-Feb-2014
• Refers: ASTM E135-13a - Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• Effective Date: 01-Dec-2013
• Refers: ASTM E691-13 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-May-2013
• Refers: ASTM E177-13 - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 01-May-2013
• Refers: ASTM E691-11 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-Nov-2011
• Refers: ASTM E2857-11 - Standard Guide for Validating Analytical Methods
• Effective Date: 01-Nov-2011
• Refers: ASTM E135-11b - Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• Effective Date: 15-Sep-2011

Overview

ASTM E572-21 is the internationally recognized standard test method for the analysis of stainless and alloy steels using wavelength dispersive X-ray fluorescence spectrometry (WDXRF). Developed by ASTM International, this standard provides a detailed methodology for rapid, multi-element determination of key alloying and residual elements in steel products. It is widely used for manufacturing control, quality assurance, and verification of compliance with product specifications in the metals industry.

The method ensures accurate quantification of important elements, offering a benchmark for precision and accuracy in analytical laboratories utilizing X-ray fluorescence technology for steel analysis.

Key Topics

• Analytical Scope: Applicable to stainless and alloy steels, the method covers the determination of elements such as chromium, nickel, cobalt, copper, manganese, molybdenum, niobium, phosphorus, silicon, sulfur, titanium, and vanadium across specified concentration ranges.
• Multi-Element Analysis: Enables rapid and simultaneous detection of multiple alloying elements, ensuring efficient process control.
• Calibration and Reference Materials: Requires the use of certified reference materials with known compositions for calibration and standardization to assure data quality.
• Precision and Accuracy: The standard includes guidance on precision, bias, and repeatability/reproducibility, supported by round-robin and interlaboratory data.
• Correction for Interferences: Provides procedures and references for correcting interelement and spectral interferences to maintain the integrity of results.
• Analyst Expertise: Intended for use by experienced analysts familiar with X-ray fluorescence instruments and analytical best practices.
• Safety Considerations: Emphasizes compliance with regulatory standards for radiation safety and safe instrument operation, including not circumventing built-in safety features.

Applications

ASTM E572-21 provides practical value in a range of contexts for elemental analysis of steels:

• Manufacturing Process Control: Used to verify that stainless and alloy steel compositions conform to specified requirements during production, ensuring consistent product quality.
• Quality Assurance: Supports testing labs in confirming that supplied steel materials meet customer or regulatory specifications.
• Benchmarking Instrument Performance: Laboratories can use the standardized procedures and provided precision data to assess the ongoing performance or equivalency of different WDXRF instruments.
• Regulatory and Contractual Compliance: Provides a recognized, validated methodology for documentation during audits or dispute resolution.
• Laboratory Method Validation: Serves as a reference for establishing and validating analytical protocols as required by ISO 17025-accredited laboratories.

Related Standards

The ASTM E572-21 test method references several supporting and related ASTM standards essential for comprehensive WDXRF analysis and data interpretation:

• ASTM E29: Practice for Using Significant Digits in Test Data
• ASTM E135: Terminology Relating to Analytical Chemistry for Metals and Ores
• ASTM E177: Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• ASTM E691: Practice for Conducting Interlaboratory Studies
• ASTM E1361: Guide for Correction of Interelement Effects in X-Ray Spectrometric Analysis
• ASTM E1621: Guide for Elemental Analysis by WDXRF Spectrometry
• ASTM E2857: Guide for Validating Analytical Methods

Utilizing ASTM E572-21 helps ensure reliable, reproducible results in the elemental analysis of stainless and alloy steels, making it an essential reference for labs, manufacturers, and quality professionals in the steel and alloy industries. For up-to-date procedures and detailed technical requirements, always consult the current published standard through ASTM.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E572 − 21
Standard Test Method for
Analysis of Stainless and Alloy Steels by Wavelength
Dispersive X-Ray Fluorescence Spectrometry
This standard is issued under the fixed designation E572; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
2 3
1.1 This test method covers the analysis of stainless and 2.1 ASTM Standards:
alloy steels by wavelength dispersive X-ray Fluorescence E29 Practice for Using Significant Digits in Test Data to
Spectrometry for the determination of the following elements: Determine Conformance with Specifications
E135 Terminology Relating to Analytical Chemistry for
Element Range, Mass Fraction %
Chromium 0.5 to 25
Metals, Ores, and Related Materials
Cobalt 0.05 to 0.45
E177 Practice for Use of the Terms Precision and Bias in
Copper 0.06 to 3.5
ASTM Test Methods
Manganese 0.3 to 5.5
Molybdenum 0.02 to 3.5
E691 Practice for Conducting an Interlaboratory Study to
Nickel 0.6 to 35
Determine the Precision of a Test Method
Niobium 0.03 to 1.3
E1361 Guide for Correction of Interelement Effects in
Phosphorus 0.01 to 0.03
Silicon 0.1 to 2
X-Ray Spectrometric Analysis
Sulfur 0.02 to 0.35
E1621 Guide for ElementalAnalysis by Wavelength Disper-
Titanium 0.008 to 0.5
sive X-Ray Fluorescence Spectrometry
Vanadium 0.02 to 0.25
E2857 Guide for Validating Analytical Methods
NOTE 1—Unless exceptions are noted, mass fraction ranges can be
extended by using suitable reference materials. Extended ranges must be
3. Terminology
verified by experimental means. This could include, but not be limited to,
Interlaboratory studies, Round Robin exercises, and other validation
3.1 For definitions of terms used in this test method, refer to
approaches. See Guide E2857 for additional guidance.
Terminology E135.
1.2 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4. Summary of Test Method
responsibility of the user of this standard to establish appro-
4.1 The test specimen is finished to a clean, uniform surface
priate safety, health, and environmental practices and deter-
and then irradiated with an X-ray beam of high energy. The
mine the applicability of regulatory limitations prior to use.
secondary X-rays produced are dispersed by means of crystals
Specific precautionary statements are given in Section 10.
and the count rates are measured by suitable detectors at
1.3 This international standard was developed in accor-
selected wavelengths. The outputs of the detectors in voltage
dance with internationally recognized principles on standard-
pulsesarecounted.Radiationmeasurementsaremadebasedon
ization established in the Decision on Principles for the
the time required to reach a fixed number of counts, or on the
Development of International Standards, Guides and Recom-
total counts obtained for a fixed time (generally expressed in
mendations issued by the World Trade Organization Technical
counts per unit time). Mass fractions of the elements are
Barriers to Trade (TBT) Committee.
determined by relating the measured radiation of unknown
specimens to analytical curves prepared using suitable refer-
1 ence materials. Both simultaneous spectrometers containing a
This test method is under the jurisdiction of ASTM Committee E01 on
Analytical Chemistry for Metals, Ores, and Related Materials and is the direct fixed-channel monochromator for each element and sequential
responsibility of Subcommittee E01.01 on Iron, Steel, and Ferroalloys.
Current edition approved May 15, 2021. Published June 2021. Originally
approved in 1976. Last previous edition approved in 2013 as E572 – 13. DOI:
10.1520/E0572-21. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Supporting data for this test method as determined by cooperative testing have contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
been filed at ASTM International Headquarters as RR:E01-1118. Contact ASTM Standards volume information, refer to the standard’s Document Summary page on
Customer Service at [e-mail]. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E572 − 21
spectrometers using a goniometer monochromator can be used equipped for vacuum or helium-flushed operation for measure-
for measurement of the elements. ment of elements of atomic number 20 (calcium) and lower.
7.3.1 Analyzing Crystals, flat or curved crystals with opti-
5. Significance and Use
mized capability for the diffraction of the wavelengths of
interest. Synthetic multilayer structures can be used in place of
5.1 This procedure is suitable for manufacturing control and
crystals.
for verifying that the product meets specifications. It provides
rapid, multi-element determinations with sufficient accuracy to 7.3.2 Collimators or Slits, for controlling the divergence of
assure product quality. The analytical performance data in- the characteristic X rays.
cluded may be used as a benchmark to determine if similar
7.3.3 Detectors, sealed and gas-flow proportional types,
X-ray spectrometers provide equivalent precision and
scintillation counters, or equivalent. Some spectrometers may
accuracy,oriftheperformanceofaparticularspectrometerhas
allow for tandem use of two different detectors to increase
changed.
sensitivity.
7.3.4 Vacuum System, providing for the determination of
5.2 It is expected that this standard will be employed by
analysts knowledgeable in the field of X-ray fluorescence elementswhoseradiationisabsorbedbyair(atomicnumber20
[calcium] and lower). The system shall consist of a vacuum
spectrometry and experienced in the use of the apparatus
specified in this test method. pump, gauge, and electrical controls to provide automatic
pump down of the optical path, and to maintain a controlled
6. Interferences pressure, usually 13 Pa (100 µm Hg) or less, controlled to 6 3
Pa (6 20 µm Hg) or better. A helium-flushed system is an
6.1 Interelement effects or matrix effects exist for some of
alternative to a vacuum system, and it must be demonstrated to
the elements listed. Mathematical correction may be used to
provide sufficient stability to achieve the demonstrated repeat-
solve for these elements. Various mathematical correction
ability performance of this test method.
procedures are commonly utilized. See Guides E1361 and
E1621. Any of these procedures that achieves analytical
7.4 Measuring System, consisting of electronic circuits ca-
accuracy equivalent to that provided by this test method is
pable of amplifying and integrating pulses received from the
acceptable.
detectors. For some measurements, a pulse height selector in
conjunctionwiththedetectorsmayberequiredtoprovidemore
6.2 Spectral Interferences—Some X-ray spectrometers will
accurate measurements. The system shall be equipped with an
not completely resolve radiation from several element combi-
appropriate device.
nations. Therefore, take care when interpreting count rates
when both elements are present. Mathematical calculations
8. Reagents and Materials
must be used to correct for the interferences. See the following
for a listing of elements with potential interferences.
8.1 Detector Gas (P-10), consisting of a mixture of 90 %
Analyte Element Potential Interference
argon and 10 % methane, for use with gas-flow proportional
Sulfur Molybdenum
counters only.
Phosphorus Molybdenum
Cobalt Iron
Vanadium Titanium
9. Reference Materials
Chromium Vanadium
Manganese Chromium
9.1 Certified Reference Materials are available from com-
mercial and government sources.
7. Apparatus
9.2 Reference Materialswithmatricessimilartothoseofthe
7.1 Specimen Preparation Equipment:
test specimens and containing varying amounts of the elements
7.1.1 Surface Grinder or Sander with Abrasive Belts or
to be determined may be used provided they have been
Disks, or Lathe, capable of providing a flat, uniform surface on
analyzed as directed in ASTM standard methods or similar
the reference materials and test specimens. Aluminum oxide
procedures established by the certifying body. These reference
and zirconium oxide belts and discs with a grit size of between
materials shall be homogeneous and free of voids and porosity.
60 and 180 have been found suitable.
9.3 The reference materials shall cover the mass fraction
7.2 Excitation Source:
ranges of the elements being sought. A minimum of three
7.2.1 X-ray Tube Power Supply, providing a constant poten-
reference materials shall be used for each element. A greater
tial of sufficient energy to produce secondary radiation from
number of calibration reference materials may be required if
the specimen for the elements specified. The generator may be
the analyst chooses to perform mathematical corrections for
equipped with a line voltage regulator and current stabilizer.
interelement effects. See Guide E1361.
7.2.2 X-ray Tubes, with targets of various high-purity ele-
ments that are capable of continuous operation at required
10. Hazards
potentials and currents and that will excite the elements to be
determined.
10.1 U.S Nuclear Regulatory Commission Standards for
7.3 Spectrometer, designed for X-ray fluorescence analysis ionizing radiation as found in the Code of Federal Regulations
and equipped with specimen holders and a specimen chamber. 10CFRPart19,“Notices,InstructionsandReportstoWorkers:
The chamber shall contain a specimen spinner, and must be Inspection and Investigations” and 10 CFR Part 20, “Standards
E572 − 21
for Protection Against Radiation” shall be observed at all directed in the equipment manufacturer’s instructions. When
X-ray emission spectrometer installations in the U.S. It is also changing P-10 cylinders, the detectors should be adequately
recommended that operating and maintenance personnel fol- flushed with detector gas before the instrument is used. After
lowtheguidelinesofsafeoperatingproceduresgiveninsimilar changing P-10 cylinders, check pulse height selector and gain
handbooks on radiation safety. settings according to the manufacturer’s instructions.
10.2 Exposure to excessive quantities of high energy radia- 12.4 Measurement Conditions—The Kα (K-L ) lines are
2,3
tionsuchasthoseproducedbyX-rayspectrometersisinjurious used for all elements in this standard. When using a sequential
tohealth.Theoperatorshouldtakeappropriateactionstoavoid spectrometer, goniometer angle settings shall be calibrated
exposinganypartoftheirbody,notonlytoprimaryXrays,but according to the manufacturer’s guidelines.
also to secondary or scattered radiation that might be present. 12.4.1 Crystals and Detectors—The following crystals and
The X-ray spectrometer should be operated as directed in detector choices are used for the elements indicated:
regulations governing the use of ionizing radiation. During
Element Crystal Detector
Chromium L1, L2 FP, SP, Sc
manufacturing, manufacturers of X-ray fluorescence spectrom-
Cobalt L1, L2 FP, SP, Sc
eters generally build into X-ray equipment appropriate shield-
Copper L1, L2 SP, FP, Sc
ing and safety interlocks that minimize the risk of excessive
Manganese L1, L2 FP, SP, Sc
Molybdenum L1, L2 Sc, SP
radiation exposure to operators. Operators should not attempt
Nickel L1, L2 SP, FP, Sc
to bypass or defeat these safety devices. Only authorized
Niobium L1, L2 Sc, SP
personnel should service X-ray spectrometers.
Phosphorus Ge FP, SP
Silicon PET, InSb FP, SP
Sulfur Ge FP, SP
11. Preparation of Reference Materials and Test
Titanium L1, L2 FP, SP
Specimens
Vanadium L1, L2 FP, SP
11.1 The analyst must choose a measurement area or
L1 = LiF(200), L2 = LiF(220)
diameter from the options built into the spectrometer. All test
FP = Flow Proportional, SP = Sealed Proportional, Sc = Scintillation
specimens and reference materials must have a flat surface of
12.4.2 Counting Time—Collect a sufficient number of
greater diameter than the chosen viewed area.
counts so that the random nature of X-ray emission and
11.2 Prepare the reference materials and test specimens to counting does not significantly influence the repeatability of
provide a clean, flat uniform surface to be exposed to the the measurements.Aminimum of 10 000 counts is required for
primary X-ray beam. One surface of a reference material may arelativecountinguncertaintyof1%atalevelofonestandard
be designated by the producer as the certified surface. The deviation, and 40 000 counts is required for 0.5 % relative
same surface preparation medium shall be used for all refer- uncertainty.
ence materials and test specimens.
13. Calibration and Drift Correction (Standardization)
11.3 As needed, refinish the surfaces of the reference
13.1 Calibration—Using the conditions established in Sec-
materials and test specimens to eliminate oxidation.
tion 12, measure a series of reference materials that cover the
12. Preparation of Apparatus required mass fraction ranges. Use at least three reference
materialsforeachelement.Prepareananalyticalcurveforeach
12.1 Prepare and operate the spectrometer in accordance
element being determined (refer to Guide E1621). For infor-
with the manufacturer’s instructions.
mation on correction of interelement effects in X-ray
NOTE 2—It is not within the scope of this test method to prescribe
fluorescence, refer to Guide E1361. Information on correction
minute details relative to the preparation of the apparatus. For a descrip-
of spectral line overlaps in wavelength dispersive X-ray
tion and specific details concerning the operation of a particular
spectrometry can be found in Guide E1621.
spectrometer, refer to the manufacturer’s manual.
13.2 Drift Correction (Standardization)—Using control ref-
12.1.1 Start-up—Turn on the power supply and electronic
erence materials, check the calibration of the X-ray spectrom-
circuits and allow sufficient time for instrument stablization
eter at a frequency consistent with the process control practice
prior to taking measurements.
of the laboratory or when the detector gas or major spectrom-
12.2 Tube Power Supply—Choose and set power supply
eter components have been changed. If the calibration check
voltage and current settings sufficient to cause fluorescence of
indicates that the spectrometer has drifted, run the drift
the elements in the method scope.
correction procedure according to the instructions in the
12.2.1 The voltage and current established as optimum for
manufacturer’s manual and retest the control reference mate-
the X-ray tube power supply in an individual laboratory shall
rial. If the calibration check is not within accepted ranges, then
be reproduced for subsequent measurements.
the spectrometer requires evaluation for malfunctions or re-
12.3 Proportional Counter Gas Flow—When a gas-flow
quired maintenance. Refer to Guide E1621 for frequency of
proportional counter is used, adjust the flow of the P-10 gas as
verification of drift correction (standardization).
13.3 Type Standardization (Optional)—After calibration
and drift correction, type standardization is an analytical
Available from the Nuclear Regulatory Commission, Public Document Room,
technique that may be employed by some laboratories. This is
Mail Stop:OWFN-1 F13, Washington, DC 20555, [phone], or via email at
[e-mail], or via the website at www.nrc.gov. usually performed utilizing the instrument manufacturer’s
E572 − 21
software and recommendations. A type reference material is either on the mass fraction of the interfering element or on the
selected that is similar in composition to the expected compo- measured count rate of the interfering element.
sition of the unknown samples.Type standardization should be
15.2 Roundingoftestresultsobtainedusingthistestmethod
performedatafrequencyintervaldeterminedbythelaboratory.
shall be performed as directed in Practice E29, Rounding
The type standardization should be verified by analyzing a
Method, unless an alternative rounding method is specifi
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E572 − 13 E572 − 21
Standard Test Method for
Analysis of Stainless and Alloy Steels by Wavelength
Dispersive X-Ray Fluorescence Spectrometry
This standard is issued under the fixed designation E572; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers the analysis of stainless and alloy steels by wavelength dispersive X-ray Fluorescence Spectrometry
for the determination of the following elements:
Element Range, Mass Fraction %
Chromium 1 to 25
Chromium 0.5 to 25
Cobalt 0.05 to 0.45
Copper 0.06 to 3.5
Manganese 0.3 to 5.5
Molybdenum 0.05 to 3.5
Molybdenum 0.02 to 3.5
Nickel 0.7 to 35
Nickel 0.6 to 35
Niobium 0.06 to 1.3
Niobium 0.03 to 1.3
Phosphorus 0.01 to 0.03
Silicon 0.2 to 2
Silicon 0.1 to 2
Sulfur 0.02 to 0.35
Titanium 0.013 to 0.5
Titanium 0.008 to 0.5
Vanadium 0.04 to 0.25
Vanadium 0.02 to 0.25
NOTE 1—Mass Unless exceptions are noted, mass fraction ranges can be extended upward by demonstration of accurate calibrations by using suitable
reference materials. Extended ranges must be verified by experimental means. This could include, but not be limited to, Interlaboratory studies, Round
Robin exercises, and other validation approaches. See Guide E2857 for additional guidance.
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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use. Specific precautionary statements are given in Section 10.
1.3 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
This test method is under the jurisdiction of ASTM Committee E01 on Analytical Chemistry for Metals, Ores, and Related Materials and is the direct responsibility of
Subcommittee E01.01 on Iron, Steel, and Ferroalloys.
Current edition approved Nov. 1, 2013May 15, 2021. Published December 2013June 2021. Originally approved in 1976. Last previous edition approved in 20122013 as
E572 – 12.E572 – 13. DOI: 10.1520/E0572-13.10.1520/E0572-21.
Supporting data for this test method as determined by cooperative testing have been filed at ASTM International Headquarters as RR:E01-1118. Contact ASTM Customer
Service at [e-mail].
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E572 − 21
2. Referenced Documents
2.1 ASTM Standards:
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
E135 Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
E1361 Guide for Correction of Interelement Effects in X-Ray Spectrometric Analysis
E1621 Guide for Elemental Analysis by Wavelength Dispersive X-Ray Fluorescence Spectrometry
E2857 Guide for Validating Analytical Methods
3. Terminology
3.1 For definitions of terms used in this test method, refer to Terminology E135.
4. Summary of Test Method
4.1 The test specimen is finished to a clean, uniform surface and then irradiated with an X-ray beam of high energy. The secondary
X-rays produced are dispersed by means of crystals and the count rates are measured by suitable detectors at selected wavelengths.
The outputs of the detectors in voltage pulses are counted. Radiation measurements are made based on the time required to reach
a fixed number of counts, or on the total counts obtained for a fixed time (generally expressed in counts per unit time). Mass
fractions of the elements are determined by relating the measured radiation of unknown specimens to analytical curves prepared
using suitable reference materials. Both simultaneous spectrometers containing a fixed-channel monochromator for each element
and sequential spectrometers using a goniometer monochromator can be used for measurement of the elements.
5. Significance and Use
5.1 This procedure is suitable for manufacturing control and for verifying that the product meets specifications. It provides rapid,
multi-element determinations with sufficient accuracy to assure product quality. The analytical performance data included 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 spectrometer has changed.
5.2 It is expected that this standard will be employed by analysts knowledgeable in the field of X-ray fluorescence spectrometry
and experienced in the use of the apparatus specified in this standard.test method.
6. Interferences
6.1 Interelement effects or matrix effects exist for some of the elements listed. Mathematical correction may be used to solve for
these elements. Various mathematical correction procedures are commonly utilized. See Guides E1361 and E1621. Any of these
procedures that achieves analytical accuracy equivalent to that provided by this test method is acceptable.
6.2 Spectral Interferences—Some X-ray spectrometers will not completely resolve radiation from several element combinations.
Therefore, take care when interpreting count rates when both elements are present. Mathematical calculations must be used to
correct for the interferences. See the following for a listing of elements with potential interferences.
Analyte Element Potential Interference
Sulfur Molybdenum
Phosphorus Molybdenum
Cobalt Iron
Vanadium Titanium
Chromium Vanadium
Manganese Chromium
7. Apparatus
7.1 Specimen Preparation Equipment:
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
E572 − 21
7.1.1 Surface Grinder or Sander with Abrasive Belts or Disks, or Lathe, capable of providing a flat, uniform surface on the
reference materials and test specimens. Aluminum oxide and zirconium oxide belts and discs with a grit size of between 60 and
180 have been found suitable.
7.2 Excitation Source:
7.2.1 X-ray Tube Power Supply, providing a constant potential or rectified power of sufficient energy to produce secondary
radiation from the specimen for the elements specified. The generator may be equipped with a line voltage regulator and current
stabilizer.
7.2.2 X-ray Tubes, with targets of various high-purity elements that are capable of continuous operation at required potentials and
currents and that will excite the elements to be determined.
7.3 Spectrometer, designed for X-ray fluorescence analysis and equipped with specimen holders and a specimen chamber. The
chamber shall contain a specimen spinner, and must be equipped for vacuum or helium-flushed operation for measurement of
elements of atomic number 20 (calcium) and lower.
7.3.1 Analyzing Crystals, flat or curved crystals with optimized capability for the diffraction of the wavelengths of interest.
Synthetic multilayer structures can be used in place of crystals.
7.3.2 Collimators or Slits, for controlling the divergence of the characteristic X rays.
7.3.3 Detectors, sealed and gas-flow proportional types, scintillation counters, or equivalent. Some spectrometers may allow for
tandem use of two different detectors to increase sensitivity.
7.3.4 Vacuum System, providing for the determination of elements whose radiation is absorbed by air (for example, silicon,
phosphorus, and sulfur).(atomic number 20 [calcium] and lower). The system shall consist of a vacuum pump, gage,gauge, and
electrical controls to provide automatic pump down of the optical path, and to maintain a controlled pressure, usually 13 Pa (100
μm Hg) or less, controlled to 6 3 Pa (6 20 μm Hg) or better. A helium-flushed system is an alternative to a vacuum system, and
it must be demonstrated to provide sufficient stability to achieve the demonstrated repeatability performance of this standard.test
method.
7.4 Measuring System, consisting of electronic circuits capable of amplifying and integrating pulses received from the detectors.
For some measurements, a pulse height selector in conjunction with the detectors may be required to provide more accurate
measurements. The system shall be equipped with an appropriate device.
8. Reagents and Materials
8.1 Detector Gas (P-10), consisting of a mixture of 90 % argon and 10 % methane, for use with gas-flow proportional counters
only.
9. Reference Materials
9.1 Certified Reference Materials are available from commercial and government sources.
9.2 Reference Materials with matrices similar to those of the test specimens and containing varying amounts of the elements to
be determined may be used provided they have been analyzed in accordance withas directed in ASTM standard methods or similar
procedures established by the certifying body. These reference materials shall be homogeneous and free of voids and porosity.
9.3 The reference materials shall cover the mass fraction ranges of the elements being sought. A minimum of three reference
materials shall be used for each element. A greater number of calibrants calibration reference materials may be required if the
analyst chooses to perform mathematical corrections for interelement effects. See Guide E1361.
10. Hazards
10.1 U.S Nuclear Regulatory Commission Standards for ionizing radiation as found in the Code of Federal Regulations 10 CFR
E572 − 21
Part 19, “Notices, Instructions and Reports to Workers: Inspection and Investigations” and 10 CFR Part 20, “Standards for
Protection Against Radiation” shall be observed at all X-ray emission spectrometer installations in the U.S. It is also
recommended that operating and maintenance personnel follow the guidelines of safe operating procedures given in similar
handbooks on radiation safety.
10.2 Exposure to excessive quantities of high energy radiation such as those produced by X-ray spectrometers is injurious to
health. The operator should take appropriate actions to avoid exposing any part of their body, not only to primary X rays, but also
to secondary or scattered radiation that might be present. The X-ray spectrometer should be operated in accordance withas directed
in regulations governing the use of ionizing radiation. During manufacturing, manufacturers of X-ray fluorescence spectrometers
generally build into X-ray equipment appropriate shielding and safety interlocks that minimize the risk of excessive radiation
exposure to operators. Operators should not attempt to bypass or defeat these safety devices. Only authorized personnel should
service X-ray spectrometers.
11. Preparation of Reference Materials and Test Specimens
11.1 The analyst must choose a measurement area or diameter from the options built into the spectrometer. All test specimens and
reference materials must have a flat surface of greater diameter than the chosen viewed area.
11.2 Prepare the reference materials and test specimens to provide a clean, flat uniform surface to be exposed to the primary X-ray
beambeam. One surface of a reference material may be designated by the producer as the certified surface. The same surface
preparation medium shall be used for all reference materials and test specimens.
11.3 As needed, refinish the surfaces of the reference materials and test specimens to eliminate oxidation.
12. Preparation of Apparatus
12.1 Prepare and operate the spectrometer in accordance with the manufacturer’s instructions.
NOTE 2—It is not within the scope of this test method to prescribe minute details relative to the preparation of the apparatus. For a description and specific
details concerning the operation of a particular spectrometer, refer to the manufacturer’s manual.
12.1.1 Start-up—Turn on the power supply and electronic circuits and allow sufficient time for instrument warm-upstablization
prior to taking measurements.
12.2 Tube Power Supply—The power supply conditions should be set according to the manufacturers recommendations. Choose
and set power supply voltage and current settings sufficient to cause fluorescence of the elements in the method scope.
12.2.1 The voltage and current established as optimum for the X-ray tube power supply in an individual laboratory shall be
reproduced for subsequent measurements.
12.3 Proportional Counter Gas Flow—When a gas-flow proportional counter is used, adjust the flow of the P-10 gas in accordance
withas directed in the equipment manufacturer’s instructions. When changing P-10 tanks,cylinders, the detectors should be
adequately flushed with detector gas before the instrument is used. After changing P-10 tanks,cylinders, check pulse height selector
and gain settings according to the manufacturer’s instructions.
12.4 Measurement Conditions—The Kα (K-L ) lines are used for all elements in this standard. When using a sequential
2,3
spectrometer, goniometer angle settings shall be calibrated according to the manufacturer’s guidelines.
12.4.1 Crystals and Detectors—The following crystals and detector choices are used for the elements indicated:
Element Crystal Detector
Chromium L1, L2 FP, SP, Sc
Cobalt L1, L2 FP, SP, Sc
Available from the Nuclear Regulatory Commission, Public Document Room, Mail Stop:OWFN-1 F13, Washington, DC 20555, [phone], or via email at
[e-mail], or via the website at www.nrc.gov.
E572 − 21
Element Crystal Detector
Copper L1, L2 SP, FP, Sc
Manganese L1, L2 FP, SP, Sc
Molybdenum L1, L2 Sc, SP
Nickel L1, L2 SP, FP, Sc
Niobium L1, L2 Sc, SP
Phosphorus Ge FP, SP
Silicon PET, InSb FP, SP
Sulfur Ge FP, SP
Titanium L1, L2 FP, SP
Vanadium L1, L2 FP, SP
L1 = LiF(200), L2 = LiF(220)
FP = Flow Proportional, SP = Sealed Proportional, Sc = Scintillation
12.4.2 Counting Time—Collect a sufficient number of counts so that the random nature of X-ray emission and counting does not
significantly influence the repeatability of the measurements. A minimum of 10 000 counts is required for a relative counting
uncertainty of 1 % at a level of one standard deviation, and 40 000 counts is required for 0.5 % relative uncertainty.
13. Calibration and StandardizationDrift Correction (Standardization)
13.1 Calibration (Preparation of Analytical Curves)—Calibration—Using the conditions established in Section 12, measure a
series of reference materials that cover the required mass fraction ranges. Use at least three reference materials for each element.
Prepare an analytical curve for each element being determined (refer to Guide E1621). For information on correction of
interelement effects in X-ray fluorescence, refer to Guide E1361. Information on correction of spectral line overlaps in wavelength
dispersive X-ray spectrometry can be found in Guide E1621.
13.2 Standardization (Analytical Curve Adjustment)—Drift Correction (Standardization)—Using control reference materials,
check the calibration of the X-ray spectrometer at a frequency consistent with the process control practice of the laboratory or when
the detector gas or major spectrometer components have been changed. If the calibration check indicates that the spectrometer has
drifted, make appropriate adjustments run the drift correction procedure according to the instructions in the manufacturer’s manual.
manual and retest the control reference material. If the calibration check is not within accepted ranges, then the spectrometer
requires evaluation for malfunctions or required maintenance. Refer to Guide E1621 for frequency of verification of
standardization.drift correction (standardization).
13.3 Type Standardization (Optional)—After calibration and drift correction, type standardization is an analytical technique that
may be employed by some laboratories. This is usually performed utilizing the instrument manufacturer’s software and
recommendations. A type reference material is selected that is similar in composition to the expected composition of the unknown
samples. Type standardization should be performed at a frequency interval determined by the laboratory. The type standardization
should be verified by analyzing a control sample or the type reference material and applying an approval criterion to the results
before analysis of unknown samples.
14. Procedure
14.1 Specimen Loading—Place each reference material or test specimen in the appropriate specimen holding container. If the
spectrometer is equipped with an automated loading device, repeatability may be improved by loading and unloading
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