ASTM D3520 for Quenching Time of Heat-Treating Fluids
ASTM D3520 Standard Test Method for Quenching Time of Heat-Treating Fluids (Magnetic Quenchometer Method)
3. Summary of Test Method
3.1 This test method determines the time for cooling a chromized nickel ball from approximately 885°C (1625°F) to approximately 354°C (670°F) when quenched in 200 mL of test fluid in a metal beaker at 21 to 27°C (70 to 81°F). The quenching time is recorded by a digital timer which is energized by a photoelectric cell from light produced by the ball at 885°C (1625°F) and which is stopped when the ball becomes magnetic (Curie Point, approximately 354°C) and is attracted by a magnet to the side of the beaker, tripping a relay to stop the timer.
4. Significance and Use
4.1 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.
4.2 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 D6200 describes the equipment and procedure for characterizing the time-temperature performance of a quenching oil through the entire cooling process.
