ASTM B391-18

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:B391 −18
Standard Specification for
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Niobium and Niobium Alloy Ingots
This standard is issued under the fixed designation B391; 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
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1.1 This specification covers unalloyed and alloyed niobium 2.1 ASTM Standards:
ingots prepared by vacuum- or plasma-arc melting or electron- E29 Practice for Using Significant Digits in Test Data to
beam melting to produce consolidated metal for processing to Determine Conformance with Specifications
various mill shapes. E2626 Guide for Spectrometric Analysis of Reactive and
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Refractory Metals (Withdrawn 2017)
1.2 The materials covered by this specification are:
1.2.1 R04200-Type 1—Reactor grade unalloyed niobium,
3. Ordering Information
1.2.2 R04210-Type 2—Commercial grade unalloyed
3.1 Orders for material under this specification shall include
niobium,
the following information, as applicable:
1.2.3 R04251-Type 3—Reactorgradeniobiumalloycontain-
3.1.1 ASTM standard number and year of issue,
ing 1 % zirconium, and
3.1.2 Type (see 1.2),
1.2.4 R04261-Type 4—Commercial grade niobium alloy
3.1.3 Quantity in weight or pieces,
containing 1 % zirconium.
3.1.4 Size, diameter and length,
1.3 Unless a single unit is used, the values stated in
3.1.5 Chemistry (see 5.2),
inch-pound units are to be regarded as standard. The values
3.1.6 Permissible overshipment (see 6.1),
given in parentheses are mathematical conversions to SI units
3.1.7 Quality and finish (see 7.2 and 7.6),
that are provided for information only and are not considered
3.1.8 Sampling (Section 8)
standard.
3.1.9 Packaging (Section 15), and
1.4 The following precautionary caveat pertains only to the
3.1.10 Required reports (Section 13).
test method portions of this specification: This standard does
4. Materials and Manufacture
not purport to address all of the safety concerns, if any,
associated with its use. It is the responsibility of the user of this
4.1 The ingot metal for all four types may be vacuum or
standard to establish appropriate safety, health, and environ-
plasma arc melted, vacuum electron-beam melted, or any
mental practices and determine the applicability of regulatory
combination of these three methods.
limitations prior to use.
5. Chemical Requirements
1.5 This international standard was developed in accor-
dance with internationally recognized principles on standard-
5.1 The finished ingot shall conform to the requirements for
ization established in the Decision on Principles for the
chemical composition as prescribed in Table 1.
Development of International Standards, Guides and Recom-
5.2 Analysis for elements not listed in Table 1 and not
mendations issued by the World Trade Organization Technical
normally expected in niobium shall not be required unless
Barriers to Trade (TBT) Committee.
specified at time of purchase.
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This specification is under the jurisdiction of ASTM Committee B10 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Reactive and Refractory Metals and Alloys and is the direct responsibility of contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Subcommittee B10.03 on Niobium and Tantalum. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved April 1, 2018. Published May 2018. Originally the ASTM website.
ɛ1 3
approvedin1962.Lastpreviouseditionapprovedin2009asB391 – 09 whichwas The last approved version of this historical standard is referenced on
withdrawn January 2018 and reinstated in April 2018. DOI: 10.1520/B0391-18. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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B391−18
TABLE 1 Chemical Requirements
Type 1 (Reactor Type 2 (Commercial Type 3 (Reactor Type 4 (Commercial
Element Grade Unalloyed Grade Unalloyed Grade Niobium–1 % Grade Niobium–1 %
Niobium) Niobium) Zirconium) Zirconium)
R04200 R04210 R04251 R04261
Max Weight % (Except Where Otherwise Specified)
Each Ingot:
Carbon 0.01 0.01 0.01 0.01
Nitrogen 0.01 0.01 0.01 0.01
Oxygen 0.015 0.025 0.015 0.025
Hydrogen 0.0015 0.0015 0.0015 0.0015
Zirconium 0.02 0.02 0.8 to 1.2 (range) 0.8 to 1.2 (range)
Tantalum 0.1 0.3 0.1 0.5
Iron 0.005 0.01 0.005 0.01
Silicon 0.005 0.005 0.005 0.005
Tungsten 0.03 0.05 0.03 0.05
Nickel 0.005 0.005 0.005 0.005
Molybden
...