Abstract

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 the requirements for porous iron-base metallic sleeve, flange, thrust, and spherical bearings that are produced from metal powders utilizing powder metallurgy (PM) technology and then impregnated with oil to supply operating lubrication.

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

1.3 This standard is a companion to Specification B438 that covers the requirements for porous oil-imptegnated bronze-base bearings.

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

1.5 Commercial bearing dimensional tolerance data are shown in Appendix Appendix X2, while engineering information regarding installation and operating parameters of PM bearings is included in Appendix Appendix X3. Additional useful information on self-lubricating bearings can be found in MPIF Standard 35 (Bearings), ISO 5755 and the technical literature.

1.6 Units With the exception of density values for which the use of the g/cm ³ unit is the long-standing practice of the PM industry, the values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not to be regarded as 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 (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

B243 Terminology of Powder Metallurgy

B438 Specification for Bronze-Base Powder Metallurgy (PM) Bearings (Oil-Impregnated)

B939 Test Method for Radial Crushing Strength, K, of Powder Metallurgy (PM) Bearings and Structural Materials

B962 Test Methods for Density of Compacted or Sintered Powder Metallurgy (PM) Products Using Archimedes Principle

B963 Test Methods for Oil Content, Oil-Impregnation Efficiency, and Interconnected Porosity of Sintered Powder Metallurgy (PM) Products Using Archimedes Principle

B966 Test Method for Permeability of Powder Metallurgy (PM) Bearings Using Nitrogen Gas

B970 Test Method for Cleanliness of Powder Metallurgy (PM) Bearings and Structural Parts

E9 Test Methods of Compression Testing of Metallic Materials at Room Temperature

E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications

E1019 Test Methods for Determination of Carbon, Sulfur, Nitrogen, and Oxygen in Steel, Iron, Nickel, and Cobalt Alloys by Various Combustion and Fusion Techniques

MPIF Standard

Keywords

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;

ICS Code

ICS Number Code 21.100.10 (Plain bearings)

DOI: 10.1520/B0439-12

ASTM International is a member of CrossRef.

ASTM B439