ASTM B393-18

Standard Specification for Niobium and Niobium Alloy Strip, Sheet, and Plate

ABSTRACT
This specification covers five grades of wrought niobium and niobium alloy strip, sheet, and plate. These are reactor grade unalloyed niobium (R04200-Type 1), commercial grade unalloyed niobium (R04210-Type 2), reactor grade niobium alloy containing 1% zirconium (R04251-Type 3), commercial grade niobium alloy containing 1% zirconium (R04261-Type 4), and RRR grade pure niobium (R0xxxx-Type 5). The RRR grade pure niobium is used in superconducting applications that require ultra high purity, making it conducive to very large grains that can adversely affect formability. It is therefore not recommended for other applications. The materials shall be made from ingots produced by vacuum or plasma arc welding, vacuum electron-beam melting, or a combination of these three methods. The various niobium mill products covered by this specification are formed with the conventional extrusion, forging, swaging, rolling, and drawing equipment normally available in metal working plants. Samples for chemical and tension testing shall be taken from the finished material after the metallurgical processing to determine conformity to this specification. The samples may be taken prior to final inspection and minor surface conditioning by abrasion and pickling shall be representative of the finished product.
SIGNIFICANCE AND USE
13.1 For the purposes of determining compliance with the specified limits for requirements of the properties listed in this specification, an observed value or a calculated value shall be rounded as indicated in accordance with the rounding method of Practice E29.
SCOPE
1.1 This specification covers five grades of wrought niobium and niobium alloy strip, sheet, and plate as follows:  
1.1.1 R04200-Type 1—Reactor grade unalloyed niobium,  
1.1.2 R04210-Type 2—Commercial grade unalloyed niobium,  
1.1.3 R04251-Type 3—Reactor grade niobium alloy containing 1 % zirconium,  
1.1.4 R04261-Type 4—Commercial grade niobium alloy containing 1 % zirconium, and.  
1.1.5 R04220-Type 5—RRR grade pure niobium.
Note 1: This grade of niobium is used in superconducting applications that require the ultra high purity. Because of the high purity the product is conducive to very large grains that can adversely affect formability. It is not recommended for other applications.  
1.2 Except for dimensional tolerances in Table 1, the values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. (A) Tolerance on thickness of sheet over 24 in. (610 mm) wide shall be ±10 % of the thickness.(B) Tolerance on width of sheared sheet shall be ±1/16 in. (±1.6 mm) and on sheared plate shall be ±1/8 in. (±3.2 mm) up to material thickness of 0.375 in. (9.5 mm).  
1.3 The following precautionary caveat pertains only to the test methods portion of this specification. 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.  
1.4 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: 31-Mar-2018
• ICS: 77.150.99 - Other products of non-ferrous metals
• Technical Committee: B10 - Reactive and Refractory Metals and Alloys
• Drafting Committee: B10.03 - Niobium, Tantalum, and Vanadium

Relations

• Replaces: ASTM B393-09e1 - Standard Specification for Niobium and Niobium Alloy Strip, Sheet, and Plate (Withdrawn 2018)
• Effective Date: 01-Apr-2018
• Refers: ASTM E8/E8M-24 - Standard Test Methods for Tension Testing of Metallic Materials
• Effective Date: 01-Jan-2024
• Refers: ASTM B391-18 - Standard Specification for Niobium and Niobium Alloy Ingots
• Effective Date: 01-Apr-2018
• Refers: ASTM E8/E8M-16 - Standard Test Methods for Tension Testing of Metallic Materials
• Effective Date: 15-Jul-2016
• Refers: ASTM E8/E8M-15 - Standard Test Methods for Tension Testing of Metallic Materials
• Effective Date: 01-Feb-2015
• Refers: ASTM E8/E8M-13 - Standard Test Methods for Tension Testing of Metallic Materials
• Effective Date: 01-Jun-2013
• Refers: ASTM E8/E8M-11 - Standard Test Methods for Tension Testing of Metallic Materials
• Effective Date: 01-Dec-2011
• Refers: ASTM B391-09e1 - Standard Specification for Niobium and Niobium Alloy Ingots (Withdrawn 2018)
• Effective Date: 01-Oct-2009
• Refers: ASTM B391-09 - Standard Specification for Niobium and Niobium Alloy Ingots
• Effective Date: 01-Oct-2009
• Refers: ASTM E29-08 - Standard Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
• Effective Date: 01-Oct-2008
• Refers: ASTM E2626-08e1 - Standard Guide for Spectrometric Analysis of Reactive and Refractory Metals (Withdrawn 2017)
• Effective Date: 15-Jun-2008
• Refers: ASTM E2626-08 - Standard Guide for Spectrometric Analysis of Reactive and Refractory Metals
• Effective Date: 15-Jun-2008
• Refers: ASTM E29-06b - Standard Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
• Effective Date: 15-Nov-2006
• Refers: ASTM E29-06a - Standard Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
• Effective Date: 15-Sep-2006
• Refers: ASTM E29-06 - Standard Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
• Effective Date: 01-May-2006

Overview

ASTM B393-18: Standard Specification for Niobium and Niobium Alloy Strip, Sheet, and Plate defines the requirements for five grades of wrought niobium and niobium alloy flat-rolled products, covering strip, sheet, and plate. This specification, developed by ASTM International, applies to materials manufactured for applications requiring high purity, consistency in mechanical properties, and strict dimensional tolerances. Adhering to internationally recognized principles, ASTM B393-18 ensures quality and reliability for manufacturers, fabricators, and end-users working with niobium and its alloys.

Key Topics

• Material Grades:

  • Reactor grade unalloyed niobium (R04200-Type 1)
  • Commercial grade unalloyed niobium (R04210-Type 2)
  • Reactor grade niobium with 1% zirconium (R04251-Type 3)
  • Commercial grade niobium with 1% zirconium (R04261-Type 4)
  • RRR (Residual Resistance Ratio) grade pure niobium (R04220-Type 5), for superconducting applications

• Manufacturing Requirements:

  • Materials are produced from ingots formed by vacuum or plasma arc melting, vacuum electron-beam melting, or a combination
  • Standard metallurgical processes: extrusion, forging, swaging, rolling, and drawing

• Chemical and Mechanical Requirements:

  • Strict limits for elements such as carbon, oxygen, nitrogen, hydrogen, zirconium, tantalum, and iron
  • Minimum standards for yield strength, tensile strength, and elongation in the annealed condition
  • Additional specific requirements for RRR grade regarding purity, grain size, electrical resistance, hardness, and surface condition

• Dimensional Specifications:

  • Tolerances for thickness, width, and length based on product type
  • Flatness and surface finish requirements to ensure suitability for demanding applications

Applications

ASTM B393-18 covers strip, sheet, and plate forms used in highly controlled environments, such as:

• Nuclear Reactors: Reactor and commercial grades of niobium and niobium-zirconium alloys provide corrosion resistance and mechanical stability under extreme conditions.
• Superconducting Devices: RRR grade pure niobium (Type 5) is specifically intended for superconducting applications requiring ultra-high purity. This includes use in superconducting magnets, medical imaging equipment (such as MRI), and particle accelerators.
• Aerospace and High-Temperature Engineering: Grades with enhanced mechanical properties are suitable for critical aerospace components and systems exposed to aggressive environments.
• Electronics and Advanced Manufacturing: Niobium and its alloys are widely used for their high melting point, electrical conductivity, and resistance to chemical attack.

It is important to note that RRR grade niobium is not recommended for general forming applications due to its large grain size, which can reduce formability.

Related Standards

• ASTM B391: Specification for Niobium and Niobium Alloy Ingots, referenced for ingot production methods and chemical composition requirements.
• ASTM E8/E8M: Test Methods for Tension Testing of Metallic Materials, referenced for mechanical property assessment.
• ASTM E29: Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications.
• ASTM E2626 (Withdrawn): Guide for Spectrometric Analysis of Reactive and Refractory Metals.

Practical Value

Compliance with ASTM B393-18 assures:

• Accurate and consistent product quality for advanced engineering applications
• Reliable sourcing criteria for manufacturers and buyers of niobium materials
• Precise documentation of chemical composition, mechanical properties, and dimensional tolerances
• Minimization of risk in critical projects by specifying accepted international standards

Keywords

Niobium strip, niobium sheet, niobium plate, niobium alloy, ASTM B393, high purity niobium, nuclear materials, superconducting niobium, niobium zirconium alloy

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:B393 −18
Standard Specification for
Niobium and Niobium Alloy Strip, Sheet, and Plate
This standard is issued under the fixed designation B393; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber 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
2.1 ASTM Standards:
1.1 This specification covers five grades of wrought nio-
B391Specification for Niobium and Niobium Alloy Ingots
bium and niobium alloy strip, sheet, and plate as follows:
E8/E8MTest Methods for Tension Testing of Metallic Ma-
1.1.1 R04200-Type 1—Reactor grade unalloyed niobium,
terials
1.1.2 R04210-Type 2—Commercial grade unalloyed
E29Practice for Using Significant Digits in Test Data to
niobium,
Determine Conformance with Specifications
1.1.3 R04251-Type 3—Reactorgradeniobiumalloycontain- E2626Guide for Spectrometric Analysis of Reactive and
ing 1% zirconium, Refractory Metals (Withdrawn 2017)
1.1.4 R04261-Type 4—Commercial grade niobium alloy
3. Terminology
containing 1% zirconium, and.
3.1 Definitions of Terms Specific to This Standard:
1.1.5 R04220-Type 5—RRR grade pure niobium.
3.1.1 lot, n—alotshallconsistofallmaterialproducedfrom
NOTE1—Thisgradeofniobiumisusedinsuperconductingapplications the same ingot at one time, with the same cross section,
that require the ultra high purity. Because of the high purity the product is
processed with the same nominal metallurgical parameters and
conducive to very large grains that can adversely affect formability. It is
heat treated at the same conditions.
not recommended for other applications.
3.1.2 plate, n—a flat product 6 in. (152.4 mm) or more in
1.2 Except for dimensional tolerances in Table 1, the values
width and greater than ⁄16 in. (4.76 mm) in thickness.
stated in inch-pound units are to be regarded as standard. The
3.1.3 sheet, n—a flat product 6 in. (152.4 mm) or more in
valuesgiveninparenthesesaremathematicalconversionstoSI
width and from 0.005 in. (0.13 mm) to ⁄16 in. (4.76 mm) in
units that are provided for information only and are not
thickness.
considered standard.
3.1.4 strip, n—aflatproduct,whichmaybesuppliedincoil,
1.3 The following precautionary caveat pertains only to the less than 6 in. (152.4 mm) in width and from 0.005 in. (0.13
mm) to ⁄16 in. (4.76 mm) in thickness.
test methods portion of this specification. This standard does
not purport to address all of the safety concerns, if any,
4. Ordering Information
associated with its use. It is the responsibility of the user of this
standard to establish appropriate safety, health, and environ- 4.1 Orders for materials under this specification shall in-
mental practices and determine the applicability of regulatory clude the following information as applicable:
4.1.1 Type and grade (Section 1),
limitations prior to use.
4.1.2 ASTM designation and year of issue,
1.4 This international standard was developed in accor-
4.1.3 Quantityinweight,numberofpieces,anddimensions,
dance with internationally recognized principles on standard-
4.1.4 Chemistry (6.3),
ization established in the Decision on Principles for the
4.1.5 Temper designation (Section 8),
Development of International Standards, Guides and Recom-
4.1.6 Permissible overshipment (9.3),
mendations issued by the World Trade Organization Technical
4.1.7 Quality and finish (10.3),
Barriers to Trade (TBT) Committee.
4.1.8 Sampling (11.2),
1 2
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 [e-mail]. 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
approvedin1999.Lastpreviouseditionapprovedin2009asB393–09 whichwas The last approved version of this historical standard is referenced on
withdrawn January 2018 and reinstated in April 2018. DOI: 10.1520/B0393-18. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B393−18
TABLE 1 Dimensional Tolerances for Niobium Flat-Rolled Products
A B
Tolerance on Thickness plus or Tolerance on Width (slit) plus or
Tolerance on Sheared Lengths, in. (mm)
minus, in. (mm) in lower table minus, in.(mm) in lower table
Thickness of Material,
Length 12 in. or 304.8 mm
Width6to24in. Width6to24in.
in. (mm) in lower table Length over 12 in. or 304.8 mm
Width under 6 in. Width under 6 in.
and under
or 152.4 to or 152.4 to
or 152.4 mm or 152.4 mm
609.6 mm 609.6 mm
Plus Minus Plus Minus
Inches
1 3
0.005 to 0.010 excl 0.0005 0.001 0.012 . ⁄16 0 ⁄32 0
1 3
0.010 to 0.015 excl 0.0007 0.001 0.015 0.015 ⁄16 0 ⁄32 0
1 3
0.015 to 0.020 excl 0.0008 0.0015 0.015 0.015 ⁄16 0 ⁄32 0
1 3
0.020 to 0.030 excl 0.0015 0.0025 0.020 0.025 ⁄16 0 ⁄32 0
1 3
0.030 to 0.060 excl 0.0025 0.0035 0.025 0.030 ⁄16 0 ⁄32 0
1 3
0.060 to 0.090 excl 0.004 0.005 0.025 0.035 ⁄16 0 ⁄32 0
1 3
0.090 to 0.125 excl 0.006 0.007 . . ⁄16 0 ⁄32 0
1 3
0.125 to 0.187 excl 0.010 0.010 . . ⁄16 0 ⁄32 0
1 5
0.187 to 0.250 excl 0.015 0.015 . . ⁄8 0 ⁄32 0
1 5
0.250 to 0.312 excl 0.020 0.020 . . ⁄8 0 ⁄32 0
3 7
0.312 to 0.375 excl 0.025 0.025 . . ⁄16 0 ⁄32 0
Millimetres
0.13 to 0.254 excl 0.013 0.025 0.30 . 1.59 0 2.38 0
0.254 to 0.381 excl 0.018 0.025 0.38 0.38 1.59 0 2.38 0
0.381 to 0.508 excl 0.020 0.038 0.38 0.38 1.59 0 2.38 0
0.508 to 0.762 excl 0.038 0.064 0.51 0.64 1.59 0 2.38 0
0.762 to 1.524 excl 0.064 0.089 0.64 0.76 1.59 0 2.38 0
1.524 to 2.286 excl 0.102 0.127 0.64 0.89 1.59 0 2.38 0
2.286 to 3.175 excl 0.15 0.18 . . 1.59 0 2.38 0
3.175 to 4.75 excl 0.25 0.25 . . 1.59 0 2.38 0
4.75 to 6.35 excl 0.38 0.38 . . 3.18 0 3.97 0
6.35 to 7.925 excl 0.51 0.51 . . 3.18 0 3.97 0
7.925 to 9.52 excl 0.64 0.64 . . 4.76 0 5.56 0
A
Tolerance on thickness of sheet over 24 in. (610 mm) wide shall be ±10 % of the thickness.
B
1 1
Tolerance on width of sheared sheet shall be ± ⁄16 in. (±1.6 mm) and on sheared plate shall be ± ⁄8 in. (±3.2 mm) up to material thickness of 0.375 in. (9.5 mm).
4.1.9 Inspection (Section 15), as prescribed in Table 3 for each lot of material supplied. End
4.1.10 Required reports (Section 17), product interstitial samples must be taken after all thermal and
4.1.11 Marking (Section 18), and chemical processing.
4.1.12 Additions to the specification and supplementary
6.4 Guide E2626 is recommended as a guide, where appli-
requirements, as required.
cable.
5. Materials and Manufacture
7. Mechanical Requirements
5.1 Material covered by this specification shall be made
7.1 Theannealedmaterialssuppliedunderthisspecification
from ingots that conform to Specification B391 and that are
shall conform to the requirements for mechanical properties as
produced by vacuum or plasma arc melting, vacuum electron-
specified in Table 4.
beam melting, or a combination of these three methods.
8. Temper Designations
5.2 The various niobium mill products covered by this
8.1 Unless otherwise stated, the materials supplied under
specification are formed with the conventional extrusion,
these specifications shall be in the fully annealed condition,
forging, swaging, rolling, and drawing equipment normally
that is, at least 90% recrystallized.
available in metal working plants.
8.2 Other temper designations, such as cold-worked temper
6. Chemical Requirements
or stress-relieved temper, can be specified as agreed upon
6.1 The niobium and niobium alloy ingots and billets for between the purchaser and the manufacturer at the time of
conversion to finished products covered by this specification purchase.
shall conform to the requirements for chemical composition as
9. Permissible Variations in Dimensions and Weight
prescribed in Table 2.
9.1 Tolerances for thickness, width, and length for flat-
6.2 The manufacturer’s ingot analysis shall be considered
rolled products covered by this specification shall be as
the chemical analysis for products supplied under this
prescribed in Table 1.
specification,exceptforendproductinterstitialsasspecifiedin
6.3. Alternately, an analysis of a representative sample of in
9.2 Flatness tolerance for sheet and plate products supplied
process or final product from the same ingot may be specified. under this specification shall be a maximum of 6% (2% for
RRR grade sheet and strip) as determined by the following
6.3 When requested by the purchaser at the time of
equation (see Fig. 1):
purchase, the manufacturer shall furnish a report certifying the
valuesoftheinterstitialelements(C,O,N,H)onendproducts Flatness, % 5 H/L 3100 (1)
~ !
B393−18
TABLE 2 Chemical Requirements
Type 1 Type 2 Type 3 Type 4 Type 5
(Reactor (Commercial (Reactor (Commercial (RRR
Grade Grade Grade Grade Superconducting
Element Unalloyed Unalloyed Niobium- Niobium- Grade Pure
Niobium) Niobium) 1% 1% Niobium
R04200 R04210 Zirconium) Zirconium) R04220
R04251 R04261
Max Weight % (Except Where Otherwise Specified)
Each ingot:
Carbon 0.01 0.01 0.01 0.01 0.0030
Nitrogen 0.01 0.01 0.01 0.01 0.0030
Oxygen 0.015 0.025 0.015 0.025 0.0040
Hydrogen 0.0015 0.0015 0.0015 0.0015 0.0005
Zirconium 0.02 0.02 0.8 to 1.2 0.8to1.2 0.010
(range) (range)
Tantalum 0.1 0.3 0.1 0.5 0.1
Iron 0.005 0.01 0.005 0.01 0.005
Silicon 0.005 0.005 0.005 0.005 0.005
Tungsten 0.03 0.05 0.03 0.05 0.007
Nickel 0.005 0.005 0.005 0.005 0.003
A
Molybdenum 0.010 0.020 0.010 0.050
A
Hafnium 0.02 0.02 0.02 0.02
Titanium 0.02 0.03 0.02 0.03 0.005
When specified:
Boron 2 ppm . 2 ppm .
Aluminum 0.002 0.005 0.002 0.005 0.005
Beryllium 0.005 . 0.005 .
B
Chromium 0.002 . 0.002 .
B
Cobalt 0.002 . 0.002 .
A
The limits shown below are for information only when the RRR ratio is greater than 260.
B
Total of these metals is 0.005 %.
TABLE 3 Additional Chemical Requirements for Finished Product (When Specified by Purchaser)
Type 2 Type 3 Type 4 Type 5
Type 1
(Commercial (Reactor (Commercial (RRR
(Reactor Grade
Grade Grade Grade Superconducting
Element Unalloyed
Unalloyed Niobium—1 % Niobium—1 % Grade Pure
Niobium)
Niobium) Zirconium) Zirconium) Niobium
R04200
R04210 R04251 R04261 R04220
Max W
...