ASTM A811-03

Standard Specification for Soft Magnetic Iron Parts Fabricated by Powder Metallurgy (P/M) Techniques

ABSTRACT
This specification covers soft magnetic iron parts fabricated by powder metallurgy (P/M) techniques. The material shall conform to the chemical composition requirements. The density of P/M parts is determined by the compressibility of the powder, the compacting pressure, and sintering practice (temperature, time, and atmosphere). The magnetic property evaluation procedures for P/M parts are presented. Three grades, defined by coercive field strength are presented; Grade 3 was developed from interlaboratory study, Grades 2 and 3 are based on a literature review and are believed to reflect the current industry capabilities. A lot shall consist of parts of the same form and dimensions, produced from a single mixed powder batch and from an unchanged process, without discontinuity in production, and submitted for inspection at one time.
SCOPE
1.1 This specification covers parts produced from iron powder metallurgy materials.
1.2 This specification deals with P/M parts in the sintered or annealed condition. Should the sintered parts be subjected to any secondary operation that causes mechanical strain, such as machining or sizing, they should be resintered or annealed.
1.3 The values stated in customary (cgs-emu and inch-pound) units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units which are provided for information only and are not considered standard.

General Information

• Status: Historical
• Publication Date: 09-May-2003
• ICS: 77.160 - Powder metallurgy
• Technical Committee: A06 - Magnetic Properties
• Drafting Committee: A06.02 - Material Specifications

Relations

• Replaces: ASTM A811-97 - Standard Specification for Soft Magnetic Iron Parts Fabricated by Powder Metallurgy (P/M) Techniques
• Effective Date: 10-May-2003
• Replaced By: ASTM A811-03(2008) - Standard Specification for Soft Magnetic Iron Parts Fabricated by Powder Metallurgy (P/M) Techniques
• Effective Date: 01-Nov-2008
• Referred By: ASTM B925-15(2022) - Standard Practices for Production and Preparation of Powder Metallurgy (PM) Test Specimens
• Effective Date: 10-May-2003
• Referred By: ASTM A1126-23 - Standard Specification for Magnetic Pure Iron
• Effective Date: 10-May-2003
• Referred By: ASTM A848-17 - Standard Specification for Low-Carbon Magnetic Iron
• Effective Date: 10-May-2003

Standards Content (Sample)

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: A 811 – 03
Standard Specification for
Soft Magnetic Iron Parts Fabricated by Powder Metallurgy
1
(P/M) Techniques
This standard is issued under the fixed designation A 811; 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.
1. Scope 3. Terminology
1.1 This specification covers parts produced from iron 3.1 The terms and symbols used in this specification are
powder metallurgy materials. defined in Terminology A 340.
1.2 This specification deals with P/M parts in the sintered or
4. Ordering Information
annealed condition. Should the sintered parts be subjected to
any secondary operation that causes mechanical strain, such as 4.1 Purchase orders for parts conforming to this specifica-
tion shall include the following information:
machining or sizing, they should be resintered or annealed.
1.3 The values stated in customary (cgs-emu and inch- 4.1.1 Reference to this specification and year of issue/
revision,
pound) units are to be regarded as standard. The values given
in parentheses are mathematical conversions to SI units which 4.1.2 Reference to an applicable part drawing,
4.1.3 Quantity required,
are provided for information only and are not considered
standard. 4.1.4 Acritical cross section of the part shall be defined and
so indicated on the applicable part drawing.The location of the
2. Referenced Documents
critical section is by mutual agreement between the purchaser
2.1 ASTM Standards: and the producer (6.2),
A 34/A 34M Practice for Sampling and Procurement Test- 4.1.5 Magnetic property requirements if they are other than
2
ing of Magnetic Materials stated in Table 1,
A 340 Terminology of Symbols and Definitions Relating to 4.1.6 Whethercertificationofchemicalanalysisormagnetic
2
Magnetic Testing property evaluation is required (Sections 5 and 7),
A 596 Test Method for Direct-Current Magnetic Properties 4.1.7 Marking and packaging requirements (Section 12),
of Materials Using the Ballistic Method and Ring Speci- and
2
mens 4.1.8 Exceptions to this specification or special require-
A 773 Test Method for dc Magnetic Properties of Materials ments such as functional testing as mutually agreed upon
Using Ring and Permeameter Procedures with dc Elec- between the producer and the purchaser.
2
tronic Hysteresigraphs
5. Chemical Composition
B 328 Test Method for Density, Oil Content, and Intercon-
5.1 The chemical composition of the parts shall conform to
nected Porosity of Sintered Metal Structural Parts and
3
Oil-Impregnated Bearings the requirements prescribed in Table 2.
5.2 Determination of metallic constituents shall be by a
E 1019 Test Methods for Determination of Carbon, Sulfur,
Nitrogen, and Oxygen in Steel and in Iron, Nickel, and method acceptable to both the producer and the purchaser.
4
Analysis of carbon, oxygen, sulfur, and nitrogen shall be done
Cobalt Alloys
in accordance with Test Methods E 1019.
1
This specification is under the jurisdiction of ASTM Committee A06 on
6. Sintered Density Requirements
Magnetic Properties and is the direct responsibility of Subcommittee A06.02 on
6.1 Magnetic and residual induction of P/M parts strongly
Material Specifications.
Current edition approved May 10, 2003. Published June 2003. Originally depend on density. The density of P/M parts is determined by
approved in 1983. Last previous edition approved in 1997 as A 811 – 97.
the compressibility of the powder, the compacting pressure,
2
Annual Book of ASTM Standards, Vol 03.04.
and sintering practice (temperature, time, and atmosphere).
3
Annual Book of ASTM Standards, Vol 02.05.
4
Annual Book of ASTM Standards, Vol 03.05.
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A 811–03
TABLE 1 Maximum Coercive Field Strength Requirements
test for aging. To determine the susceptibility of the parts to
Grade Coercive Field Strength aging, the test ring(s) should be heated for either 100 h at 150
6 5°C or 600 h at 100 6 5°C and the coercive field strength
1 1.8 Oe (140 A/m)
2 2.0 Oe (160 A/m)
remeasured. A change in coercive field strength of 10 % or
3 2.3 Oe (180 A/m)
more of the original value is evidence that aging has occurred.
7.7 Since magnetic properties are strongly affected by
processconditions,refertoAppendixX1fortypicalvaluesand
TABLE 2 Chemical Requirements (weight percent)
explanatory notes.
Element %
8. Workmanship, Finish and Appearance
Carbon, max 0.03
Oxygen, max 0.10
8.1 The parts shall be uniform in composition and uniform
Nitrogen, max 0.01
A
in density within critical s
...