ASTM F256-05(2020)
(Specification)Standard Specification for Chromium-Iron Sealing Alloys with 18 or 28 Percent Chromium (Withdrawn 2023)
Standard Specification for Chromium-Iron Sealing Alloys with 18 or 28 Percent Chromium (Withdrawn 2023)
ABSTRACT
This specification covers two chromium-iron alloys, one is UNS K91800 with nominally 18% chromium, balance iron, and the other is UNS K92801 with nominally 28% chromium, both in strip, bar, wire, and rod forms intended primarily for sealing to glass in electronic applications. The alloys are classified by nominal chemical composition, specifically by chromium content, in two types: Type I (UNS K91800) and Type II (UNS K92801). The materials shall show no evidence of transformation to martensite. For Type I alloy, the austenite formed during heat treating will transform to martensite at or above room temperature. The presence of austenite, as may be noted in Type II alloy, is acceptable if the thermal expansion requirement is met. Different tests shall be performed in order to determine the following properties of the alloys: thermal expansion, Rockwell hardness, and tensile strength.
SCOPE
1.1 This specification covers two chromium-iron alloys, the former, (UNS K91800), nominally 18 % chromium, balance iron, the latter, (UNS K92801), nominally 28 % chromium, in strip, bar, wire, and rod forms intended primarily for sealing to glass in electronic applications.
Note 1: UNS K92801 should only be considered for use at service temperatures below 300°C. The alloy is prone to sigma phase formation at temperatures close to 620°C, and exhibits brittle mechanical behavior after prolonged exposures at temperatures close to 475°C.
1.2 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.
1.3 The following hazard caveat pertains only to the test method portion, Sections 16 and 17, 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.
WITHDRAWN RATIONALE
This specification covered two chromium-iron alloys, the former, (UNS K91800), nominally 18 % chromium, balance iron, the latter, (UNS K92801), nominally 28 % chromium, in strip, bar, wire, and rod forms intended primarily for sealing to glass in electronic applications.
Formerly under the jurisdiction of F01 on Electronics, this specification was withdrawn in November 2023. This standard is being withdrawn without replacement because Committee F01 was disbanded.
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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:F256 −05 (Reapproved 2020)
Standard Specification for
Chromium-Iron Sealing Alloys with 18 or 28 Percent
1
Chromium
ThisstandardisissuedunderthefixeddesignationF256;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope A370Test Methods and Definitions for Mechanical Testing
of Steel Products
1.1 This specification covers two chromium-iron alloys, the
E3Guide for Preparation of Metallographic Specimens
former, (UNS K91800), nominally 18% chromium, balance
E18Test Methods for Rockwell Hardness of Metallic Ma-
iron, the latter, (UNS K92801), nominally 28% chromium, in
terials
strip, bar, wire, and rod forms intended primarily for sealing to
E29Practice for Using Significant Digits in Test Data to
glass in electronic applications.
Determine Conformance with Specifications
NOTE 1—UNS K92801 should only be considered for use at service
E38Methods for Chemical Analysis of Nickel-Chromium
temperaturesbelow300°C.Thealloyispronetosigmaphaseformationat
and Nickel-Chromium-Iron Alloys
temperatures close to 620°C, and exhibits brittle mechanical behavior
E228Test Method for Linear Thermal Expansion of Solid
after prolonged exposures at temperatures close to 475°C.
Materials With a Push-Rod Dilatometer
1.2 The values stated in inch-pound units are to be regarded
F14Practice for Making andTesting Reference Glass-Metal
as standard. The values given in parentheses are mathematical
Bead-Seal
conversions to SI units that are provided for information only
F140Practice for Making Reference Glass-Metal Butt Seals
and are not considered standard.
and Testing for Expansion Characteristics by Polarimetric
1.3 The following hazard caveat pertains only to the test
Methods
method portion, Sections 16 and 17, of this specification. This
F144Practice for Making Reference Glass-Metal Sandwich
standard does not purport to address all of the safety concerns,
Seal and Testing for Expansion Characteristics by Polari-
if any, associated with its use. It is the responsibility of the user
metric Methods
of this standard to establish appropriate safety, health, and
environmental practices and determine the applicability of
3. Terminology
regulatory limitations prior to use.
3.1 Definitions of Terms Specific to This Standard:
1.4 This international standard was developed in accor-
3.1.1 bar:
dance with internationally recognized principles on standard-
1
3.1.1.1 hot-finished rounds, squares, and hexagons, ⁄4 in.
ization established in the Decision on Principles for the
(6.4 mm) and over in diameter or size.
Development of International Standards, Guides and Recom-
1
mendations issued by the World Trade Organization Technical 3.1.1.2 hot-finished flats, ⁄4 in. to 10 in. (6.4 to 254 mm),
1
Barriers to Trade (TBT) Committee. inclusive, in width and ⁄8 in. (3.2 mm) and over in thickness.
3.1.1.3 cold-finished rounds, squares, octagons, hexagons
2. Referenced Documents
1
and shapes, over ⁄2 in. (12.7 mm) in diameter or size.
2
2.1 ASTM Standards: 3
3.1.1.4 cold-finishedflats, ⁄8in.(9.5mm)andoverinwidth
1
and ⁄8 in. (3.2 mm) and over in thickness (see Discussions).
3
1
Discussion—Widths less than ⁄8 in. (9.5 mm) and thick-
This specification is under the jurisdiction of ASTM Committee F01 on
3
Electronics and is the direct responsibility of Subcommittee F01.03 on Metallic
nesseslessthan ⁄16in.(4.8mm)aregenerallydescribedasflat
Materials, Wire Bonding, and Flip Chip.
wire.
Current edition approved May 1, 2020. Published June 2020. Originally
1 3
Discussion—Thicknesses of ⁄8 in. (3.2 mm) to under ⁄16 in.
approved in 1951 as F256–51T. Last previous edition approved in 2015 as
F256–94(2015). Consolidated with F257 in 1972. DOI: 10.1520/F0256-05R20. (4.8 mm) can also be described as cold-rolled strip or, if in cut
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
lengths, bar.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
3.1.2 rod—hot-rolled, or hot-rolled, annealed, and pickled,
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. rounds, squares, octagons, hexagons and shapes, in coils, for
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
F256−05 (2020)
1 3
subsequent cold drawing or cold rolling, ⁄4 in. or ⁄4 in. (6.4 or 6. Process
19.0 mm) in diameter or size.
6.1 The purchaser shall specify that the al
...
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: F256 − 05 (Reapproved 2020)
Standard Specification for
Chromium-Iron Sealing Alloys with 18 or 28 Percent
1
Chromium
This standard is issued under the fixed designation F256; 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 A370 Test Methods and Definitions for Mechanical Testing
of Steel Products
1.1 This specification covers two chromium-iron alloys, the
E3 Guide for Preparation of Metallographic Specimens
former, (UNS K91800), nominally 18 % chromium, balance
E18 Test Methods for Rockwell Hardness of Metallic Ma-
iron, the latter, (UNS K92801), nominally 28 % chromium, in
terials
strip, bar, wire, and rod forms intended primarily for sealing to
E29 Practice for Using Significant Digits in Test Data to
glass in electronic applications.
Determine Conformance with Specifications
NOTE 1—UNS K92801 should only be considered for use at service
E38 Methods for Chemical Analysis of Nickel-Chromium
temperatures below 300°C. The alloy is prone to sigma phase formation at
and Nickel-Chromium-Iron Alloys
temperatures close to 620°C, and exhibits brittle mechanical behavior
E228 Test Method for Linear Thermal Expansion of Solid
after prolonged exposures at temperatures close to 475°C.
Materials With a Push-Rod Dilatometer
1.2 The values stated in inch-pound units are to be regarded
F14 Practice for Making and Testing Reference Glass-Metal
as standard. The values given in parentheses are mathematical
Bead-Seal
conversions to SI units that are provided for information only
F140 Practice for Making Reference Glass-Metal Butt Seals
and are not considered standard.
and Testing for Expansion Characteristics by Polarimetric
1.3 The following hazard caveat pertains only to the test
Methods
method portion, Sections 16 and 17, of this specification. This
F144 Practice for Making Reference Glass-Metal Sandwich
standard does not purport to address all of the safety concerns,
Seal and Testing for Expansion Characteristics by Polari-
if any, associated with its use. It is the responsibility of the user
metric Methods
of this standard to establish appropriate safety, health, and
environmental practices and determine the applicability of
3. Terminology
regulatory limitations prior to use.
3.1 Definitions of Terms Specific to This Standard:
1.4 This international standard was developed in accor-
3.1.1 bar:
dance with internationally recognized principles on standard-
1
3.1.1.1 hot-finished rounds, squares, and hexagons, ⁄4 in.
ization established in the Decision on Principles for the
(6.4 mm) and over in diameter or size.
Development of International Standards, Guides and Recom-
1
mendations issued by the World Trade Organization Technical 3.1.1.2 hot-finished flats, ⁄4 in. to 10 in. (6.4 to 254 mm),
1
Barriers to Trade (TBT) Committee. inclusive, in width and ⁄8 in. (3.2 mm) and over in thickness.
3.1.1.3 cold-finished rounds, squares, octagons, hexagons
2. Referenced Documents
1
and shapes, over ⁄2 in. (12.7 mm) in diameter or size.
2
2.1 ASTM Standards: 3
3.1.1.4 cold-finished flats, ⁄8 in. (9.5 mm) and over in width
1
and ⁄8 in. (3.2 mm) and over in thickness (see Discussions).
3
1
Discussion—Widths less than ⁄8 in. (9.5 mm) and thick-
This specification is under the jurisdiction of ASTM Committee F01 on
3
Electronics and is the direct responsibility of Subcommittee F01.03 on Metallic
nesses less than ⁄16 in. (4.8 mm) are generally described as flat
Materials, Wire Bonding, and Flip Chip.
wire.
Current edition approved May 1, 2020. Published June 2020. Originally
1 3
Discussion—Thicknesses of ⁄8 in. (3.2 mm) to under ⁄16 in.
approved in 1951 as F256 – 51 T. Last previous edition approved in 2015 as
(4.8 mm) can also be described as cold-rolled strip or, if in cut
F256 – 94 (2015). Consolidated with F257 in 1972. DOI: 10.1520/F0256-05R20.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
lengths, bar.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
3.1.2 rod—hot-rolled, or hot-rolled, annealed, and pickled,
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. rounds, squares, octagons, hexagons and shapes, in coils, for
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
F256 − 05 (2020)
1 3
subsequent cold drawing or cold rolling, ⁄4 in. or ⁄4 in. (6.4 or 6. Process
19.0 mm) in diameter or size.
6.1 The purchaser shall specify that the alloy be made by
3.1.3 strip—cold-finished coils
...
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