ASTM D7038 Standard Test Method for Evaluation of Moisture Corrosion Resistance of Automotive Gear Lubricants
1. Scope
1.1 This test method covers a test procedure for evaluating the rust and corrosion inhibiting properties of a gear lubricant while subjected to water contamination and elevated temperature in a bench-mounted hypoid differential housing assembly. This test method is commonly referred to as the L-33-1 test.
1.2 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 considered standard.
1.2.1 Exceptions - (1) where there is no direct SI equivalent such as screw threads and national pipe threads/diameters, and (2) the values stated in SI units are to be regarded as standard for the definitions in 12.2, and for SI units where there are no direct inch-pounds equivalent units.
1.3 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.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D235 Specification for Mineral Spirits (Petroleum Spirits) (Hydrocarbon Dry Cleaning Solvent)
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
2.2 ASTM Standard:
2.3 Society of Automotive Engineers Standards:
J308 Information Report on Axle and Manual Transmission Lubricants
J2360 Lubricating Oil, Gear Multipurpose (Metric) Military Use
2.4 U.S. Military Specifications:
MIL-PRF-2105E Lubricating Oil, Gear, General Multipurpose
MIL-P-3420F NOX-RUST Paper
3. Terminology
3.1 Definitions ofTerms Specific to This Standard:
3.1.1 corrosion, n - an alteration of a finished metal surface by discoloration, accompanied by roughening not attributable to mechanical action.
3.1.2 downtime, n - an interruption of power to the test unit for a period greater than ten seconds.
3.1.3 rust, n - a special case of corrosion, which always deteriorates or alters the original surface condition.
3.1.3.1 Discussion - Rust always has color (usually, but not limited to red, yellow, brown, black) and one of the following descriptive characteristics: (1) depth; the rusted surface is built up relative to that of adjacent areas. (2) texture; the surface may appear to be etched, scaly or otherwise visibly different than adjacent areas.
3.1.4 stain, n - a surface modification that is attributable to discoloration only.
