ASTM D4340 Standard Test Method for Corrosion of Cast Aluminum Alloys in Engine Coolants Under Heat-Rejecting Conditions
5.1 Heat-Transfer Corrosion Cell - The assembled corrosion cell is shown schematically in Fig. 1. It is assembled from components, some of which require glass blowing or machining. The glass O-ring cell shall be constructed from two glass O-ring joints joined to an additional middle section of glass tubing of the same diameter to make a total length of 53 cm (21 in.). Heat-resistant O-rings shall be used. Internal pressure shall be monitored using a suitable pressure gage, and a pressure-relief valve shall be installed to protect against bursting.
5.1.1 The top assembly plate (shown in Fig. 2) shall be constructed of stainless steel, and the heat-transfer bar and bottom assembly plate (also illustrated in Fig. 2) shall preferably be constructed of stainless steel. Mild steel may be used for the heat-transfer bar and bottom assembly plate.
5.2 Temperature Controller, with high-temperature alarm option and temperature control range up to at least 150°C (302°F). Use Type J thermocouple. A heavy-duty electrical power relay or SCR solid-state contactor is connected to the temperature controller to carry the current load to the band heaters.
5.3 Electrical Relay, 30-amp rating. The relay is changed after about every 50 000 cycles to prevent contact welding.
5.4 Band Heaters, at least 950 W, 120-V ac, 5.1-cm (2-in.) inside diameter, 12.7-cm (5-in.) length.
5.5 Ultrasonic Cleaner, about 50 W, for cleaning aluminum test samples.
5.6 Vacuum Oven, with temperature range up to about 150°C (302°F) for thoroughly drying cast aluminum samples.
5.7 Vacuum Pump, for use with vacuum oven.
5.8 Thermal Cutoff, for over-temperature protection, located 1.3 cm (1/2 in.) from the heat-transfer bar.
5.9 Compressed Air, for pressurizing test cell.
5.10 Clear Plastic Safety Shield, for protection against bursting.
6.1 The engine coolant concentrate shall be sampled in accordance with Test Method D1176.
7. Metal Test Specimen
7.1 Cast Aluminum, conforming to UNS A03190 is used. Specimen size is 6.5 cm (2.6 in.) in diameter, 1.3 cm (0.5 in.) thick. Fig. 2 illustrates location of the thermocouple holes.
8. Test Solution
8.1 Dissolve 165 mg of reagent grade sodium chloride in 750 mL of distilled or deionized water, and then add 250 mL of the test coolant. This is sufficient solution for two tests.