ASTM D6138 Method for Corrosion-Preventive Properties of Lubricating Greases
ASTM D6138 Standard Test Method for Determination of Corrosion-Preventive Properties of Lubricating Greases Under Dynamic Wet Conditions (Emcor Test)
9. Procedure
9.1 Prepare the apparatus by removing all traces of grease from the previous tests by wiping the plummer blocks. Wash the plummer blocks with the solvent rinse solution followed by water. Dry thoroughly using a lint-free cloth.
9.2 Distribute 10g more or less 0.1 g of the grease evenly in each test bearing using a spatula and taking care to avoid air bubbles. Rotate the outer ring slightly with a gloved hand to assist distribution. Smear all the external surfaces of the bearing with additional grease.
9.3 Prepare two bearings for each grease to be tested. Each pair of bearings is used for one test.
9.4 Place the adapter sleeves, bearings, and V-ring seals in position on the shaft and finger-tighten the sleeve nuts.
9.5 Place the shaft complete with greased bearings in position in the test rig, taking care that the bearings are centered in the plummer blocks.
9.6 Place the top halves of the plummer block in position and finger-tighten the locking screws.
9.7 Press the V-ring seals up against the plummer blocks using the special tool supplied with the test machine.
9.8 Run the test rig for 30 more or less 5 min at 83 more or less 5 rpm immediately after assembly to distribute the grease evenly.
9.9 Without delay, remove the top halves of the plummer blocks and introduce 10 mL of distilled water, synthetic sea water or sodium chloride solution into each side of each plummer block (a total of 20 more or less 1 mL) using a pipette. Refit top halves of plummer blocks and finger-tighten the locking screws.
9.10 Without delay, operate the test rig according to the following schedule:
9.10.1 Run 8 h more or less 10 min, stop, allow to stand 16 h more or less 10 min;
9.10.2 Run 8 h more or less 10 min, stop, allow to stand 16 h more or less 10 min;
9.10.3 Run 8 h more or less 10 min, stop, allow to stand 108 h more or less 2 h.
9.11 Immediately following the time schedule (9.10), remove the top halves of the plummer blocks. Lift the shaft and bearings on to a suitable support on the work bench. Unscrew the sleeve nuts one or two revolutions. Tap the bearings lightly to free them, then pull bearings, sleeves, and seals off the shaft.
9.12 Dismantle the bearings for inspection by prying balls out of the cage pockets until the outer ring can be removed.
9.13 Wash the outer rings in the solvent rinse solution and dry, using a lint-free cloth. Examine immediately.
10. Rating Procedure
10.1 Visually examine the outer ring track area for rust or etch spots, without the aid of any optical adjuncts, and evaluate as described in Table 1. Fig. 1 illustrates the area to be examined. Fig. 2 illustrates examples intended to assist in the assessment of the degree of corrosion. Ignore any staining through which the underlying metal surface is clearly visible.
