ASTM A811-15

Standard Specification for Soft Magnetic Iron Parts Fabricated by Powder Metallurgy 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 powder metallurgy 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 SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to customary (cgs-emu and inch-pound) units, which are provided for information only, and are not considered standard.  
1.4 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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 31-Mar-2015
• ICS: 77.160 - Powder metallurgy
• Technical Committee: A06 - Magnetic Properties
• Drafting Committee: A06.02 - Material Specifications

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:A811 −15
Standard Specification for
Soft Magnetic Iron Parts Fabricated by Powder Metallurgy
1
Techniques
This standard is issued under the fixed designation A811; 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 B962 Test Methods for Density of Compacted or Sintered
Powder Metallurgy (PM) Products Using Archimedes’
1.1 This specification covers parts produced from iron
Principle
powder metallurgy materials.
E1019 Test Methods for Determination of Carbon, Sulfur,
1.2 This specification deals with powder metallurgy parts in
Nitrogen, and Oxygen in Steel, Iron, Nickel, and Cobalt
the sintered or annealed condition. Should the sintered parts be
Alloys by Various Combustion and Fusion Techniques
subjected to any secondary operation that causes mechanical
3. Terminology
strain,suchasmachiningorsizing,theyshouldberesinteredor
annealed.
3.1 The terms and symbols used in this specification are
defined in Terminology A340.
1.3 The values stated in SI units are to be regarded as
standard. The values given in parentheses are mathematical
4. Ordering Information
conversions to customary (cgs-emu and inch-pound) units,
4.1 Purchase orders for parts conforming to this specifica-
which are provided for information only, and are not consid-
tion shall include the following information:
ered standard.
4.1.1 Reference to this specification and year of issue/
1.4 This standard does not purport to address all of the
revision,
safety concerns, if any, associated with its use. It is the
4.1.2 Reference to an applicable part drawing,
responsibility of the user of this standard to establish appro-
4.1.3 Quantity required,
priate safety and health practices and determine the applica-
4.1.4 Acritical cross section of the part shall be defined and
bility of regulatory limitations prior to use.
so indicated on the applicable part drawing.The location of the
critical section is by mutual agreement between the user and
2. Referenced Documents
the producer (6.2),
2
2.1 ASTM Standards:
4.1.5 Magnetic property requirements if they are other than
A34/A34M Practice for Sampling and Procurement Testing
stated in Table 1,
of Magnetic Materials
4.1.6 Whethercertificationofchemicalanalysisormagnetic
A340 Terminology of Symbols and Definitions Relating to
property evaluation is required (Sections 5 and 7),
Magnetic Testing
4.1.7 Marking and packaging requirements (Section 12),
A596/A596M Test Method for Direct-Current Magnetic
and
Properties of Materials Using the Ballistic Method and
4.1.8 Exceptions to this specification or special require-
Ring Specimens
ments such as functional testing as mutually agreed upon
A773/A773M Test Method for Direct Current Magnetic
between the producer and the user.
Properties of Low Coercivity Magnetic Materials Using
5. Chemical Composition
Hysteresigraphs
5.1 The chemical composition of the parts shall conform to
the requirements prescribed in Table 2.
1
This specification is under the jurisdiction of ASTM Committee A06 on
5.2 Determination of metallic constituents shall be by a
Magnetic Properties and is the direct responsibility of Subcommittee A06.02 on
method acceptable to both the producer and the user. Analysis
Material Specifications.
of carbon, oxygen, sulfur, and nitrogen shall be done in
Current edition approved April 1, 2015. Published April 2015. Originally
approved in 1983. Last previous edition approved in 2008 as A811 – 03 (2008).
accordance with Test Methods E1019.
DOI: 10.1520/A0811-15.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 6. Sintered Density Requirements
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
6.1 Magnetic and residual induction of powder metallurgy
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. parts strongly depend on density. The density of powder
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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A811−15
TABLE 1 Maximum Coercive Field Strength Requirements
Therefore, when requested by the user, the producer shall test
Grade Coercive Field Strength for aging. To determine the susceptibility of the parts to aging,
1 140 A/m (1.8 Oe) the test ring(s) should be heated in air for either 100 h at 150
2 160 A/m (2.0 Oe)
65°Cor600hat100 6 5 °C and the coercive field strength
3 180 A/m (2.3 Oe)
remeasured. A change in coercive field strength of 10 % or
more of the original value is evidence that aging has occurred.
TABLE 2 Chemical Requirement
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: A811 − 03 (Reapproved 2008) A811 − 15
Standard Specification for
Soft Magnetic Iron Parts Fabricated by Powder Metallurgy
1
(P/M) Techniques
This standard is issued under the fixed designation A811; 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
1.1 This specification covers parts produced from iron powder metallurgy materials.
1.2 This specification deals with P/M powder metallurgy 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) SI units are to be regarded as standard. The values given in
parentheses are mathematical conversions to SI units customary (cgs-emu and inch-pound) units, which are provided for
information only, and are not considered standard.
1.4 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 and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2
2.1 ASTM Standards:
A34/A34M Practice for Sampling and Procurement Testing of Magnetic Materials
A340 Terminology of Symbols and Definitions Relating to Magnetic Testing
A596/A596M Test Method for Direct-Current Magnetic Properties of Materials Using the Ballistic Method and Ring Specimens
A773/A773M Test Method for Direct Current Magnetic Properties of Low Coercivity Magnetic Materials Using Hysteresig-
raphs
B328B962 Test Method for Density, Oil Content, and Interconnected Porosity of Sintered Metal Structural Parts and
Oil-Impregnated BearingsMethods for Density of Compacted or Sintered Powder Metallurgy (PM) Products Using
Archimedes’ Principle (Withdrawn 2009)
E1019 Test Methods for Determination of Carbon, Sulfur, Nitrogen, and Oxygen in Steel, Iron, Nickel, and Cobalt Alloys by
Various Combustion and Fusion Techniques
3. Terminology
3.1 The terms and symbols used in this specification are defined in Terminology A340.
4. Ordering Information
4.1 Purchase orders for parts conforming to this specification shall include the following information:
4.1.1 Reference to this specification and year of issue/revision,
4.1.2 Reference to an applicable part drawing,
4.1.3 Quantity required,
4.1.4 A critical cross section of the part shall be defined and so indicated on the applicable part drawing. The location of the
critical section is by mutual agreement between the purchaseruser and the producer (6.2),
4.1.5 Magnetic property requirements if they are other than stated in Table 1,
1
This specification is under the jurisdiction of ASTM Committee A06 on Magnetic Properties and is the direct responsibility of Subcommittee A06.02 on Material
Specifications.
Current edition approved Nov. 1, 2008April 1, 2015. Published December 2008April 2015. Originally approved in 1983. Last previous edition approved in 20032008 as
A811 – 03.A811 – 03 (2008). DOI: 10.1520/A0811-03R08.10.1520/A0811-15.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
A811 − 15
TABLE 1 Maximum Coercive Field Strength Requirements
Grade Coercive Field Strength
1 1.8 Oe (140 A/m)
2 2.0 Oe (160 A/m)
3 2.3 Oe (180 A/m)
TABLE 1 Maximum Coercive Field Strength Requirements
Grade Coercive Field Strength
1 140 A/m (1.8 Oe)
2 160 A/m (2.0 Oe)
3 180 A/m (2.3 Oe)
4.1.6 Whether certification of chemical analysis or magnetic property evaluation is required (Sections 5 and 7),
4.1.7 Marking and packaging requirements (Section 12), and
4.1.8 Exceptions to this specification or special requirements such as functional testing as mutually agreed upon between the
producer and the purchaser.user.
5. Chemical Composition
5.1 The chemical composition of the parts shall conform to the requirements prescribed in Table 2.
5.2 Determination o
...