Glassware Corrosion test

Laboratory tests have been one of the primary means for evaluating engine coolants. One of the most common tests is a simple beaker-type procedure for evaluating the effects of engine coolants on metal specimens under controlled laboratory conditions, the glassware corrosion test. The typical glassware corrosion tests include ASTM D1384, JIS K2234 metal corrosion property, CEC corrosion test in glassware. There are also numerous varied versions from OEMs, etc.

In ASTM D1384 glassware corrosion test, specimens of metals typical of those present in engine cooling systems, i.e. steel, copper, brass, solder, cast aluminum and cast iron, are totally immersed in aerated engine coolant solutions for 336 h at 88°C. The concentration of the engine coolant to be tested shall be mixed with the proper qua

The corrosion-inhibitive properties of the test solution are evaluated on the basis of the weight changes incurred by the specimens. Each test is run in triplicate, and the average weight change is determined for each metal. Report corrosion weight loss as a positive value and weight gain as a negative value. If no sign is given to the value it will be interpreted as a weight loss.

This test is simulating heat receiving conditions inside an engine. Although this immersion test is typical of many simple corrosion tests, it is easy to list a number of variations from service conditions that might have an effect on the credibility of results from this test. For example, the coolant temperature in service may vary from ambient to very hot, and then cools again to ambient, the higher temperatures in service may increase corrosion rates and can contribute to the breakdown of glycols.

However, when the tests are used and results are interpreted properly, the corrosion test in glassware will serve a useful purpose if users have a thorough understanding of its function in the over-all evaluation of engine coolants. We shall also understand that the results of this test method cannot stand alone as evidence of satisfactory corrosion inhibition. The actual service value of an engine coolant formulation can be determined only by more comprehensive laboratory, bench, and field tests.