ASTM B439

This specification covers the standard requirements for porous metallic sleeve, flange, thrust, and spherical iron-base bearings that are produced from mixed metal powder metallurgy technology and then impregnated with oil to supply operating lubrication. Porous iron-base bearings shall be produced by compaction of a mixture of elemental iron powder and copper, tin, pre-alloyed bronze or graphite powders and sintering in a furnace having a protective atmosphere at a specified time and temperature cycle. The interconnected or open porosity in the bearings shall be filled to the required volume either by an extended soaking in hot oil or preferably by a vacuum impregnation operation with lubricating oil which is a high-grade turbine oil with antifoaming additives and containing corrosion and oxidation inhibitors. Each of the iron-base bearing material shall conform to the chemical composition requirements for iron, carbon, graphite, copper, and tin as shall be determined by chemical analysis. The physical properties for each of the bearing material shall be within the prescribed wet density, oil content, and impregnation efficiency limits. The radial crushing strength and bearing breaking load of the oil-impregnated bearing material determined on a plain sleeve bearing or a test specimen prepared from a flange or spherical bearing shall also meet the minimum and maximum mechanical strength values.

This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.

1. Scope

1.1 This specification covers porous metallic sleeve, flange, thrust, and spherical iron-base bearings that are produced from mixed metal powder utilizing powder metallurgy (PM) technology and then impregnated with oil to supply operating lubrication.

1.2 Included are the specifications for the chemical, physical, and mechanical requirements of those ferrous PM materials that have been developed and standardized specifically for use in the manufacture of these self-lubricating bearings.

1.3 This specification accompanies Specification B 438/B 438M that covers the requirements for Bronze-Base Powder Metallurgy (PM) Bearings (Oil-Impregnated).

1.4 Typical applications for iron-base bearings are discussed in Appendix X1.

1.5 Commercial bearing dimensional tolerance data are shown in Appendix X2, while engineering information regarding installation and operating parameters of PM bearings is included in Appendix X3. Additional useful information on self-lubricating bearings can be found in MPIF Standard 35 (Bearings) and the technical literature.

1.6 With the exception of density values for which the g/cm³ unit is the industry standard, the values stated in inch-pound units are to be regarded as standard. The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.

1.7 The following safety hazards caveat pertains only to the test methods described in 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 and health practices and determine the applicability of regulatory limitations prior to use.

2. Referenced Documents

B243 Terminology of Powder Metallurgy
B328 Test Method for Density, Oil Content, and Interconnected Porosity of Sintered Metal Structural Parts and Oil-Impregnated Bearings
B438/B438M Specification for Bronze Powder Metallurgy (P/M) Bearings (Oil-Impregnated)
B939 Test Method for Radial Crushing Strength, , of Powder Metallurgy (P/M) Bearings and Structural Materials
E1019 Test Methods for Determination of Carbon, Sulfur, Nitrogen, and Oxygen in Steel and in Iron, Nickel, and Cobalt Alloys
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
E9 Test Methods of Compression Testing of Metallic Materials at Room Temperature
ISO 2795 Plain Bearings from Sintered Metal-Dimension and Tolerances
MPIF Standard 35 Materials Standards for PM Self-Lubricating Bearings
SI 10 American National Standard for Use of the International System of Units (SI): The Modernized Metric System

Index Terms

bearing breaking load; impregnated density; interconnected porosity; oil content; oil-impregnated bearings; open porosity; PM bearings; porous metallic bearings; PV factor; PV limit; radial crushing strength; self-lubricating bearings; Ferrous metals/alloys; Iron sintered bearings--specifications; K (strength constant); Oil content; Oil-impregnated bearings--specifications; Radial crushing force; Sintered metal bearings--specifications; ICS Number Code 21.100.10

Citing ASTM Standards

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