ASTM A751-96
(Test Method)Standard Test Methods, Practices, and Terminology for Chemical Analysis of Steel Products
Standard Test Methods, Practices, and Terminology for Chemical Analysis of Steel Products
SCOPE
1.1 This standard covers definitions, reference methods, practices, and guides relating to the chemical analysis of steel, stainless steel, and related alloys. It includes both wet chemical and instrumental techniques.
1.2 Directions are provided for handling chemical requirements, product analyses, residual elements, and reference standards, and for the treatment and reporting of chemical analysis data.
1.3 This standard applies only to those product standards which include this standard or parts thereof as a requirement.
1.4 In cases of conflict, the product specification requirements shall take precedence over the requirements of this standard.
1.5 Attention is directed to Practice A880 when there may be a need for information on criteria for evaluation of testing laboratories.
1.6 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.
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An American National Standard
Designation: A 751 – 96
Standard Test Methods, Practices, and Terminology for
Chemical Analysis of Steel Products
This standard is issued under the fixed designation A 751; 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.
This standard has been approved for use by agencies of the Department of Defense.
INTRODUCTION
This standard was prepared to answer the need for a single document that would include all aspects
of obtaining and reporting the chemical analysis of steel, stainless steel, and related alloys. Such
subjects as definitions of terms and product (check) analysis variations (tolerances) required
clarification. Requirements for sampling, meeting specified limits, and treatment of data usually were
not clearly established in product specifications.
It is intended that this standard will contain all requirements for the determination of chemical
composition of steel, stainless steel, or related alloys so that product specifications will need contain
only special modifications and exceptions.
1. Scope Inspection of Steel, Stainless Steel, and Related Alloys
E 29 Practice for Using Significant Digits in Test Data to
1.1 This standard covers definitions, reference methods,
Determine Conformance with Specifications
practices, and guides relating to the chemical analysis of steel,
E 30 Test Methods for Chemical Analysis of Steel, Cast
stainless steel, and related alloys. It includes both wet chemical
Iron, Open-Hearth Iron, and Wrought Iron
and instrumental techniques.
E 50 Practices for Apparatus, Reagents, and Safety Precau-
1.2 Directions are provided for handling chemical require-
tions for Chemical Analysis of Metals
ments, product analyses, residual elements, and reference
E 59 Practice for Sampling Steel and Iron for Determination
standards, and for the treatment and reporting of chemical
of Chemical Composition
analysis data.
E 60 Practice for Photometric and Spectrophotometric
1.3 This standard applies only to those product standards
Methods for Chemical Analysis of Metals
which include this standard or parts thereof as a requirement.
E 212 Test Method for Spectrographic Analysis of Carbon
1.4 In cases of conflict, the product specification require-
and Low-Alloy Steel by the Rod-to-Rod Technique
ments shall take precedence over the requirements of this
E 293 Test Method for Spectrographic Determination of
standard.
Acid-Soluble Aluminum in Low-Alloy Steel By the Solu-
1.5 Attention is directed to Practice A 880 when there may
tion Technique
be a need for information on criteria for evaluation of testing
E 322 Method for X-Ray Emission Spectrometric Analysis
laboratories.
of Low-Alloy Steels and Cast Irons
1.6 This standard does not purport to address all of the
E 327 Test Method for Optical Emission Spectrometric
safety concerns, if any, associated with its use. It is the
Analysis of Stainless Type 18-8 Steels by the Point-to-
responsibility of the user of this standard to establish appro-
Plane Technique
priate safety and health practices and determine the applica-
E 350 Test Methods for Chemical Analysis of Carbon Steel,
bility of regulatory limitations prior to use.
Low-Alloy Steel, Silicon Electrical Steel, Ingot Iron, and
2. Referenced Documents Wrought Iron
E 352 Test Methods for Chemical Analysis of Tool Steels
2.1 ASTM Standards:
and Other Similar Medium- and High-Alloy Steels
A 880 Practice for Criteria for Use in Evaluation of Testing
E 353 Test Methods for Chemical Analysis of Stainless,
Laboratories and Organizations for the Examination and
These test methods, practices, and terminology are under the jurisdiction of
ASTM Committee A-1 on Steel, Stainless Steel and Related Alloys, and are the Annual Book of ASTM Standards, Vol 01.03.
direct responsibility of Subcommittee A01.13 on Methods of Mechanical Testing. Annual Book of ASTM Standards, Vol 14.02.
Current edition approved Sept. 10, 1996. Published November 1997. Originally Annual Book of ASTM Standards, Vol 03.05.
published as A 751 – 77. Last previous edition A 751 – 95. Annual Book of ASTM Standards, Vol 03.06.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
A 751
Heat-Resisting, Maraging, and Other Similar Chromium- to the purchaser and determined by analyzing a test sample,
Nickel-Iron Alloys preferably obtained during the pouring of the steel, for the
E 354 Test Methods for Chemical Analysis of High- elements designated in a specification.
Temperature, Electrical, Magnetic, and Other Similar Iron, 3.1.1.2 product, check or verification analysis—a chemical
Nickel, and Cobalt Alloys analysis of the semifinished or finished product, usually for the
E 403 Test Method for Optical Emission Spectrometric purpose of determining conformance to the specification re-
Analysis of Carbon and Low-Alloy Steel by the Point-to- quirements. The range of the specified composition applicable
Plane Technique to product analysis is normally greater than that applicable to
E 404 Test Method for Spectrographic Determination of heat analysis in order to take into account deviations associated
Boron in Carbon and Low-Alloy Steel by the Point-to- with analytical reproducibility (Note 1) and the heterogeneity
Plane Technique of the steel.
E 415 Test Method for Optical Emission Vacuum Spectro-
NOTE 1—All of the chemical analysis procedures referenced in this
metric Analysis of Carbon and Low-Alloy Steel
document include precision statements with reproducibility data with the
E 421 Test Method for Spectrographic Determination of
exception of Test Methods E 30.
Silicon and Aluminum in High-Purity Iron
3.1.1.3 product analysis tolerances (Note 2)—a permissible
E 485 Test Method for Optical Emission Vacuum Spectro-
variation over the maximum limit or under the minimum limit
metric Analysis of Blast Furnace Iron by the Point-to-Plane
of a specified element and applicable only to product analyses,
Technique
not cast or heat analyses.
E 548 Guide for General Criteria Used for Evaluating
NOTE 2—The term “analysis tolerance” is often misunderstood. It does
Laboratory Competence
not apply to cast or heat analyses determined to show conformance to
E 572 Test Method for X-Ray Emission Spectrometric
5 specified chemical limits. It applies only to product analysis and becomes
Analysis of Stainless Steel
meaningful only when the heat analysis of an element falls close to one of
E 663 Practice for Flame Atomic Absorption Analysis
the specified limits. For example, stainless steel UNS 30400 limits for
E 743 Guide for Spectrochemical Laboratory Quality As-
chromium are 18.00 to 20.00 %. A heat that the producer reported as
surance
18.01 % chromium may be found to show 17.80 % chromium by a user
E 851 Practice for Evaluation of Spectrochemical Labora- performing a product analysis. If the product analysis tolerance for such a
chromium level is 0.20 %, the product analysis of 17.80 % chromium
tories
would be acceptable. A product analysis of 17.79 % would not be
E 882 Guide for Accountability and Quality Control in the
acceptable.
Chemical Analysis Laboratory
3.1.1.4 proprietary analytical method—a non-standard ana-
E 1019 Test Methods for Determination of Carbon, Sulfur,
lytical method, not published by ASTM, utilizing reference
Nitrogen, Oxygen, and Hydrogen in Steel and in Iron,
standards traceable to the National Institute of Standards and
Nickel, and Cobalt Alloys
Technology (NIST) (when available) or other sources refer-
E 1024 Guide for Chemical Analysis of Metals and Metal
enced in Section 10.
Bearing Ores by Flame Atomic Absorption Spectropho-
3.1.1.5 referee analysis—performed using ASTM methods
tometry
listed in 9.1.1 and NIST reference standards or methods and
E 1063 Test Method for X-Ray Emission Spectrometric
reference standards agreed upon between parties. The selection
Determination of Cerium and Lathanum in Carbon and
of a laboratory to perform the referee analysis shall be a matter
Low-Alloy Steels
of agreement between the supplier and the purchaser.
E 1086 Test Method for Optical Emission Vacuum Spectro-
3.1.1.6 certified reference material—a specimen of material
metric Analysis of Stainless Steel by the Point-to-Plane
specially prepared, analyzed, and certified for chemical content
Excitation Technique
under the jurisdiction of a recognized standardizing agency or
E 1087 Practice for Sampling Molten Steel from a Ladle
group, such as the National Institute of Standards and Tech-
Using An Immersion Sampler to Produce a Specimen for
nology, for use by analytical laboratories as an accurate basis
Emission Spectrochemical Analysis
for comparison. Reference samples should bear sufficient
E 1097 Guide for Direct Current Plasma Emission Spec-
resemblance to the material to be analyzed so that no signifi-
trometry Analysis
cant differences are required in procedures or corrections (for
E 1184 Practice for Electrothermal (Graphite Furnace)
example, for interferences or inter-element effects).
Atomic Absorption Analysis
3.1.1.7 working reference materials—reference materials
E 1282 Guide for Specifying the Chemical Compositions
used for routine analytical control and traceable to NIST
and Selecting Sampling Practices and Quantitative Analy-
standards and other recognized standards when appropriate
sis Methods for Metals and Alloys
standards are available.
E 1329 Practice for Verification and the Use of Control
3.1.2 Pertaining to Elements:
Charts in Spectrochemical Analysis
3.1.2.1 intentionally added unspecified element—an ele-
3. Terminology
ment added in controlled amounts at the option of the producer
3.1 Definitions: to obtain desirable characteristics.
3.1.1 Pertaining to Analyses: 3.1.2.2 residual element—a specified or unspecified ele-
3.1.1.1 cast or heat (formerly ladle) analysis—applies to ment, not intentionally added, originating in raw materials,
chemical analyses representative of a heat of steel as reported refractories, or air.
A 751
3.1.2.3 specified element—an element controlled to a speci- 6. Product Analysis Requirements
fied range, maximum or minimum, in accordance with the
6.1 For product analysis, the range of the specified chemical
requirements of the product specification.
composition is normally greater (designated product analysis
3.1.2.4 trace element—a residual element that may occur in
tolerances) than that applicable to heat analyses to take into
very low concentrations, generally less than 0.01 %.
account deviations associated with analytical reproducibility
and the heterogeneity of the steel. If several determinations of
4. Concerning the Specification of Chemical Composition
any element in the heat are made, they may not vary both
Requirements
above and below the specified range.
6.2 Product analysis tolerances may not be used to deter-
4.1 It is recommended that Guide E 1282 be consulted as a
mine conformance to the specified heat or cast analysis unless
guide for specifying the chemical compositions for steels.
permitted by the individual material specification.
4.2 The recommended practice for specifying chemical
6.3 Product analysis tolerances, where available, are given
composition limits is to limit the number of significant figures
in the individual material specifications or in the general
for each element so that the number of figures to the right of the
requirement specifications.
decimal point conforms to the following:
Chemical Maximum Number of Figures to 7. Unspecified Elements (Note 4)
Concentration the Right of the Decimal Point
7.1 Reporting analyses of unspecified elements is permitted.
Up to 0.010 % — 0.XXXX or may be expressed as ppm
Up to 0.10 % — 0.XXX
NOTE 4—All commercial metals contain small amounts of various
0.10 to 3.00 % — 0.XX
elements in addition to those which are specified. It is neither practical nor
Over 3.0 % — 0.X
necessary to specify limits for every unspecified element that might be
4.3 For those cases in which the composition range spans
present, despite the fact that the presence of many of these elements is
often routinely determined by the producer.
either 0.10 % or 3.0 %, the number of figures to the right of the
decimal is to be determined by that indicated by the upper
7.2 Analysis limits shall be established for specific elements
limit.
rather than groups of elements such as “all others,”“ rare
4.4 Technical considerations may dictate the employment of
earths,” and “balance.”
less than the number of figures to the right of the decimal as
8. Sampling
previously recommended.
8.1 Cast or Heat Analyses:
NOTE 3—The recommendations should be employed to reduce the
8.1.1 Samples shall be taken, insofar as possible, during the
number of significant figures, such as from 18.00 % to 18.0 %, but a
casting of a heat, at a time which, in the producer’s judgment,
significant figure should never be added unless there is a technical reason
best represents the composition of the cast.
for so doing.
8.1.2 In case the heat analysis samples or analyses are lost
or inadequate, or when it is evident that the sample does not
5. Cast or Heat Analysis
truly represent the heat, representative samples may be taken
5.1 The producer shall perform analyses for those elements
from the semifinished or finished product, in which case such
specified in the material specification. The results of such
samples may be analyzed to satisfy the specified requirements.
analyses shall conform to the requirements specified in the
The analysis shall meet the specified limits for heat analysis.
material specification.
8.2 Check, Product, or Verification Analyses—Unless oth-
5.1.1 For multiple heats, either individual heat or cast
erwise specified, the latest revision of Practice E 59 shall be
analysis or an average heat or cast analysis shall be reported. If
used as a guide for sampling.
significant variations in heat or cast size are involved, a
9. Test Methods
weighted average heat or cast analysis, based on the relative
9.1 This section lists some test methods that have been
quantity of metal in each heat or cast, shall be reported.
found acceptable for chemical analysis of steels.
5.1.2 For consumable electrode remelted material, a heat is
9.1.1 The following ASTM wet chemical test methods have
defined as all the ingots remelted by the same process from a
been found acceptable as referee test methods and as a base for
primary heat. The heat analysis shall be obtained from one
standardizing
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