ASTM A839-02

Standard Specification for Iron-Phosphorus Powder Metallurgy (P/M) Parts for Soft Magnetic Applications

SCOPE
1.1 This specification covers parts produced from iron-phosphorus powder metallurgy materials. These parts are used in magnetic applications requiring higher permeability and electrical resistivity and lower coercive field strength than attainable routinely from parts produced from iron powder.
1.2 Two powder types are covered; Type I containing nominally 0.45 % phosphorus, and Type II containing nominally 0.8 % phosphorus.
1.3 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.
1.4 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-Oct-2002
• ICS: 77.160 - Powder metallurgy
• Technical Committee: A06 - Magnetic Properties
• Drafting Committee: A06.02 - Material Specifications

Relations

• Replaced By: ASTM A839-02(2008) - Standard Specification for Iron-Phosphorus Powder Metallurgy (P/M) Parts for Soft Magnetic Applications
• Effective Date: 01-May-2008
• Referred By: ASTM A1126-23 - Standard Specification for Magnetic Pure Iron
• Effective Date: 10-Oct-2002
• Referred By: ASTM A848-17 - Standard Specification for Low-Carbon Magnetic Iron
• Effective Date: 10-Oct-2002
• Referred By: ASTM B925-15(2022) - Standard Practices for Production and Preparation of Powder Metallurgy (PM) Test Specimens
• Effective Date: 10-Oct-2002
• Referred By: ASTM B783-19 - Standard Specification for Materials for Ferrous Powder Metallurgy (PM) Structural Parts
• Effective Date: 10-Oct-2002

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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 839 – 02
Standard Specification for
Iron-Phosphorus Powder Metallurgy (P/M) Parts for Soft
Magnetic Applications
This standard is issued under the fixed designation A 839; 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 Nitrogen, and Oxygen in Steel and in Iron, Nickel, and
Cobalt Alloys
1.1 This specification covers parts produced from iron-
phosphorus powder metallurgy materials. These parts are used
3. Ordering Information
in magnetic applications requiring higher permeability and
3.1 Purchase orders for parts conforming to this specifica-
electrical resistivity and lower coercive field strength than
tion shall include the following information:
attainable routinely from parts produced from iron powder.
3.1.1 Reference to this specification and year of issue/
1.2 Two powder types are covered; Type I containing
revision.
nominally 0.45 % phosphorus, and Type II containing nomi-
3.1.2 The type of powder to be used (see 4.1 and Table 1).
nally 0.8 % phosphorus.
3.1.3 Reference to an applicable part drawing.
1.3 This specification deals with P/M parts in the sintered or
3.1.4 Quantity required.
annealed condition. Should the sintered parts be subjected to
3.1.5 Acritical cross section of the part shall be defined and
any secondary operation that causes mechanical strain, such as
so indicated on the applicable part drawing.The location of the
machining or sizing, they should be resintered or annealed.
critical section is by mutual agreement between the user and
1.4 The values stated in customary (cgs-emu and inch-
the producer (see 5.2).
pound) units are to be regarded as standard. The values given
3.1.6 Magnetic property requirements if they are other than
in parentheses are mathematical conversions to SI units which
stated in Table 2.
are provided for information only and are not considered
3.1.7 Whethercertificationofchemicalanalysisormagnetic
standard.
property evaluation is required (see Sections 4 and 6).
2. Referenced Documents 3.1.8 Markingandpackagingrequirements(seeSection11).
3.1.9 Whether testing for magnetic aging is required.
2.1 ASTM Standards:
3.1.10 Exceptions to this specification or special require-
A 34/A 34M Practice for Procurement, Testing and Sam-
ments such as functional testing, as mutually agreed upon
pling of Magnetic Materials
between the producer and the user.
A 596/A 596M Test Method for Direct Current Magnetic
Properties of Materials Using the Ballistic Method and
4. Chemical Composition
Ring Specimens
4.1 The chemical composition of the parts shall conform to
A 773/A 773M Test Method for dc Magnetic Properties of
the requirements prescribed in Table 1.
Materials Using Ring and Permeameter Procedures with
2 4.2 Chemical analysis for phosphorus shall be determined
dc Electronic Hysteresigraphs
by wet chemistry in accordance with a method to be agreed
B 328 Test Method for Density, Oil Content, and Intercon-
upon between the user and the producer. Analysis of carbon,
nected Porosity of Sintered Powder Metal Structural Parts
oxygen, and nitrogen shall be done in accordance with Test
and Oil-Impregnated Bearings
Methods E 1019.
E 1019 Test Methods for Determination of Carbon, Sulfur,
5. Sintered Density Requirements
5.1 Magnetic and residual induction of P/M parts strongly
This specification is under the jurisdiction of ASTM Committee A06 on depend on density. The density of P/M parts is determined by
Magnetic Properties and is the direct responsibility of Subcommittee A06.02 on
the compressibility of the powder, the compacting pressure,
Materials Specifications.
and sintering practice (temperature, time, and atmosphere).
Current edition approved Oct. 10, 2002. Published November 2002. Originally
published as A 839 – 85. Last previous edition A 839/A 839M – 96.
Annual Book of ASTM Standards, Vol 03.04.
3 4
Annual Book of ASTM Standards, Vol 02.05. Annual Book of ASTM Standards, Vol 03.05.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
A 839–02
TABLE 1 Chemical Composition Requirements (in Weight
for aging. To determine the susceptibility of the parts to aging,
Percent)
the test ring(s) should be heated for either 100 h at 150°C or
Element Type I Type II
600 h at 100°C and the coercive field strength remeasured. A
Phosphorus 0.40/0.50 0.75/0.85
change in coercive field strength of 10 % or more of the
Carbon, max 0.03 0.03
original value is evidence that aging has occurred.
Oxygen, max 0.10 0.10
6.7 Since magnetic properties are strongly affected by
Nitrogen, max 0.01 0.01
A
Iron balance balance process conditions, refer to theAppendix X1-Appendix X3 for
A
Iron is the balance by difference. Quantitative analysis of this element is not typical values and explanatory notes.
required.
7. Workmanship, Finish and Appearance
TABLE 2 Maximum Coercive Field Strength Requirements
7.1 The parts shall be uniform in composition and uniform
Grade Powder Type I (0.45 % P) Powder Type II (0.8 % P) in density within critical sections.
7.2 If parts are sectioned or fractured, there shall be no
1 1.4 Oe (110 A/m) 1.2 Oe (96 A/m)
2 1.8 Oe (140 A/m) 1.4 Oe (110 A/m)
readily recognizable defects.
3 2.0 Oe (160 A/m) 1.7 Oe (140 A/m)
8. Sampling
8.1 A lot shall consist of parts of the same form and
5.2 Parts produced in conformance with this specification
dimensions, produced from a single mixed powder batch and
shall have a minimum sintered density of 6.8 g/cm (6800
from an unchanged process, without discontinuity in produc-
kg/m ) in the critical section of the part. The critical section
tion, and submitted for inspection at one time.
shall be defined by agreement between the user and the
8.2 The user and the producer shall agree upon a represen-
producer.
tative number of specimens for testing.
5.3 Sintered density shall be determined in accordance with
9. Rejection and Rehearing
Test Method B 328.
9.1 Parts that fail to conform to the requirements of this
6. Magnetic Property Requirements
specification may be rejected. Rejection should be reported to
6.1 Due to the nature of P/M parts production, magnetic
the producer or supplier promptly and in writing. In case of
testing of each lot is not required by this specification.
dissatisfaction with the results of the test, the producer or
However, it is strongly recommended that the user require the
supplier may make claim for a rehearing.
producer to conduct periodic magnetic evaluations and to
9.2 The disposition of rejected parts shall be subject to
certify the results obtained. Such magnetic property evalua-
agreement between the user and the producer.
tions shall be conducted in the following manner.
10. Certification
6.2 When requested, each lot of parts should be sintered
withatleastoneandpreferablythreeringtestspecimenswhich
10.1 When specified in the purchase order or contract, the
comply with the geometric requirements listed in Practice
user shall be furnished certification that samples representing
A 34/A 34M. The ring specimen(s) shall be produced from the
each lot have either been tested or inspected as directed in this
same mixed lot of powder used to produce the parts.
specification and the requirements have been met.
6.3 The dc magnetic propertie
...