ASTM A839/A839M-96

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

SCOPE
1.1 This specification covers parts produced from iron phosphorous powder metallurgy materials. These parts are used in magnetic applications requiring higher permeability and electrical resistivity and lower coercive force 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 re-sintered or annealed.  
1.4 The values stated in either customary (cgs-emu and inch-pound) units or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system shall be used independently of the other. Combining values from two systems may result in nonconformance with this specification.

General Information

• Status: Historical
• Publication Date: 31-Dec-1995
• ICS: 77.160 - Powder metallurgy
• Technical Committee: A06 - Magnetic Properties
• Drafting Committee: A06.02 - Material Specifications

Standards Content (Sample)

Designation: A 839/A 839M – 96
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Specification for
Iron-Phosphorus Powder Metallurgy (P/M) Parts for Soft
1
Magnetic Applications
This standard is issued under the fixed designation A 839/A 839M; 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
4
Cobalt Alloys
1.1 This specification covers parts produced from iron-
3. Ordering Information
phosphorus powder metallurgy materials. These parts are used
in magnetic applications requiring higher permeability and
3.1 Purchase orders for parts conforming to this specifica-
electrical resistivity and lower coercive force than attainable tion shall include the following information:
routinely from parts produced from iron powder. 3.1.1 Reference to this specification and year of issue/
revision.
1.2 Two powder types are covered; Type I containing
3.1.2 The type of powder to be used (see 4.1 and Table 1).
nominally 0.45 % phosphorus, and Type II containing nomi-
3.1.3 Reference to an applicable part drawing.
nally 0.8 % phosphorus.
3.1.4 Quantity required.
1.3 This specification deals with P/M parts in the sintered or
3.1.5 A critical cross section of the part shall be defined and
annealed condition. Should the sintered parts be subjected to
so indicated on the applicable part drawing. The location of the
any secondary operation that causes mechanical strain, such as
critical section is by mutual agreement between the purchaser
machining or sizing, they should be re-sintered or annealed.
and the producer (see 5.2).
1.4 The values stated in either customary (cgs-emu and
3.1.6 Magnetic property requirements if they are other than
inch-pound) units or SI units are to be regarded separately as
stated in Table 2.
standard. Within the text, the SI units are shown in brackets.
3.1.7 Whether certification of chemical analysis or magnetic
The values stated in each system are not exact equivalents;
property evaluation is required (see Sections 4 and 6).
therefore, each system shall be used independently of the other.
3.1.8 Marking and packaging requirements (see Section 11).
Combining values from the two systems may result in noncon-
3.1.9 Exceptions to this specification or special require-
formance with this specification. ments such as functional testing as mutually agreed upon
between the producer and the purchaser.
2. Referenced Documents
4. Chemical Composition
2.1 ASTM Standards:
4.1 The chemical composition of the parts shall conform to
A 34 Practice for Procurement, Testing and Sampling of
the requirements prescribed in Table 1.
2
Magnetic Materials
4.2 Chemical analysis for phosphorus shall be determined
A 596 Test Method for Direct-Current Magnetic Properties
by wet chemistry in accordance with a method to be agreed
of Materials Using the Ballistic Method and Ring Speci-
upon between the purchaser and the producer. Analysis of
2
mens
carbon, oxygen, and nitrogen shall be done in accordance with
A 773 Test Method for D-C Magnetic Properties of Mate- Test Methods E 1019.
rials Using Ring and Permeameter Procedures with D-C
5. Sintered Density Requirements
2
Electronic Hysteresigraphs
5.1 Magnetic and residual induction of P/M parts strongly
B 328 Test Method for Density, Oil Content, and Intercon-
depend on density. The density of P/M parts is determined by
nected Porosity of Sintered Powder Metal Structural Parts
3
the compressibility of the powder, the compacting pressure,
and Oil-Impregnated Bearings
and sintering practice (temperature, time, and atmosphere).
E 1019 Test Methods for Determination of Carbon, Sulfur,
5.2 Parts produced in conformance with this specification
3
shall have a minimum sintered density of 6.8 g/cm [6800
3
1
This specification is under the jurisdiction of ASTM Committee A-6 on kg/m ] in the critical section of the part. The critical section
Magnetic Properties and is the direct responsibility of Subcommittee A06.02 on
shall be defined by agreement between the purchaser and the
Materials Specifications.
producer.
Current edition approved Oct. 10, 1996. Published December 1996. Originally
published as A 839 – 85. Last previous edition A 839 – 87.
2
Annual Book of ASTM Standards, Vol 03.04.
3 4
Annual Book of ASTM Standards, Vol 02.05. Annual Book of ASTM Standards, Vol 03.06.
1

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A 839/A 839M
TABLE 1 Chemical Requirements (in weight percent)
6.7 Since magnetic properties are strongly affected by
process conditions, refer to the Appendixes X1 through X3 for
Element Type I Type II
typical values and explanatory notes.
Phosphorus 0
...