ASTM D3520-04

1.1 This test method covers a procedure for making a comparative evaluation of the quenching speed characteristics of petroleum fluids used in the quenching of metals by means of the Magnetic Quenchometer.

Note 1—A comparison method for testing the hardenability of steel is Test Method A 255.

Note 2—An additional comparison method for evaluation of the quenching speed characteristics of petroleum fluids used in the quenching of metals is Test Method D 6200.

1.2 This test method provides a measure of changes in oil chemistry due to contamination, base oil degradation, and additive drag-out during use. This test measures changes in the quenching speed characteristics of petroleum fluids at the high temperature (>354°C). This test method does not reliably predict metallurgical performance.

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 requirements prior to use.

The results obtained by the test method described are useful as guides in selecting fluids with respect to quenching speed characteristics desired for metal quenching applications.

Note 3—Although this test method has been found useful for some water-based fluids, the statistical significance of the test has been established only by round-robin testing of petroleum-based fluids.

These results will provide a measure of quenching speed (cooling rate) from approximately 885°C (1625°F) to 354°C (670°F) and are not directly proportional to hardness obtainable on metals quenched therein as many other factors are involved in the quenching process in actual plant operation with production parts.

Note 4—Test Method D 6200 describes the equipment and procedure for characterizing the time-temperature performance of a quenching oil through the entire cooling process.

FIG. 1 Magnetic Quenchometer

FIG. 2 Test Sequence in Beaker