ASTM B953-21

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: B953 − 21
Standard Practice for
Sampling Magnesium and Magnesium Alloys for
1
Spectrochemical Analysis
This standard is issued under the fixed designation B953; 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* 3. Summary of Practice
1.1 This practice describes the sampling of magnesium and 3.1 Molten metal representative of the furnace melt is
magnesium-base alloys to obtain a chill-cast sample suitable poured directly into a specified mold (described in 5.2.1)to
for quantitative atomic emission spectrochemical analysis. The produce a chill-cast disk. The disk is machined to a specific
disk in the region to be excited is representative of the melt and depth that represents the average melt composition and pro-
gives a repeatability of results that approach that of the duces an acceptable surface for excitation.
reference materials used.
3.2 Fabricated, cast, or wrought products may be excited
1.2 This practice describes the procedure for representative directly without remelting; however, accuracy of results may
sampling of molten metal. suffer in highly alloyed samples due to the potential for
elemental segregation.
1.3 The values stated in SI units are to be regarded as
standard. The values given in parentheses after SI units are
4. Significance and Use
provided for information only and are not considered standard.
4.1 This practice, used in conjunction with the following
1.4 This standard does not purport to address all of the
quantitative atomic emission spectrochemical test method,
safety concerns, if any, associated with its use. It is the
B954, is suitable for use in manufacturing control, material or
responsibility of the user of this standard to establish appro-
product acceptance, certification, and research and develop-
priate safety, health, and environmental practices and deter-
ment.
mine the applicability of regulatory limitations prior to use.
5. Apparatus
Specific Warning Statements are given in 5.1.
1.5 This international standard was developed in accor-
5.1 Ladle, capable of holding a minimum of 400 g (7.7 oz)
dance with internationally recognized principles on standard-
of molten metal, with a handle of sufficient length to reach into
ization established in the Decision on Principles for the
a furnace, trough, or crucible sufficiently deep to obtain a
Development of International Standards, Guides and Recom-
sample representative of the melt being cast. The ladle may be
mendations issued by the World Trade Organization Technical
lightly coated with a tightly adhering ladle wash that will not
Barriers to Trade (TBT) Committee.
contaminate the sample. Boron nitride can be applied at
elevated temperatures to form a tenacious coating.
2. Referenced Documents
(Warning—Trace moisture in the coating or on the tool may
2
2.1 ASTM Standards: cause dangerous spattering. Preheat all sampling tools and
molds prior to use.)
B954 Test Method for Analysis of Magnesium and Magne-
sium Alloys by Atomic Emission Spectrometry
5.2 Sample Molds, capable of producing homogeneous
E1257 Guide for Evaluating Grinding Materials Used for
chill-cast disks having smooth surfaces, free of surface pockets
Surface Preparation in Spectrochemical Analysis
and porosity. These castings should have a spectrochemical
response similar to the reference materials used in preparing
the analytical curves and must have a repeatability from
1
These practices are under the jurisdiction of ASTM Committee B07 on Light
excitation-to-excitation of no more than 2 % relative on major
Metals and Alloys and are the direct responsibility of Subcommittee B07.04 on
alloying elements. They must be representative of the melt in
Magnesium Alloy Cast and Wrought Products.
the region excited. Several types of molds have been found
Current edition approved May 1, 2021. Published June 2021. Originally
acceptable:
approved in 2007. Last previous edition approved in 2013 as B953 – 13. DOI:
10.1520/B0953-21.
5.2.1 Type A, Open Cavity Mold, is shown in Fig. 1. The
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
advantage of this mold is its simple design and ability to
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
produce a sample disk that can be excited around the entire
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. annular area. Mold dimensions can be modified to produ
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