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1769305 
Journal Article 
Coolants for high requirements: sophisticated corrosion testing in comparison to standard methods 
Andersohn, G; Eppel, K; Trossmann, T; Berger, C 
2010 
1 
Materialwissenschaft und Werkstofftechnik
ISSN: 0933-5137 
41 
2 
95-105 
WOS:000275808100004 
Due to the need of increasing energy efficiency, fuel
economy and reduction of pollution, modern combustion engines are being designed with light
metals, greater turbocharging and decreased construction space (downsizing). At the same time,
the included cooling systems are similarly being impacted by smaller designs. Consequently, the
reduced coolant volume leads to a smaller amount of inhibitors, which is available to prevent
corrosion. Further on, emerging thermal loads have significantly increased due to elevated power
densities, higher engine temperatures and greater metal-coolant fluxes, which place greater
importance on high temperature corrosion protection. The operating conditions, like coolant flow
rates, turbulence and pressure bounds, have great impact on erosion-corrosion protection and
cavitation protection. Therefore, the verification of corrosion protection under heat rejecting
conditions, coolant flow, turbulence and independent pressure load are highly desired for
practice and research. The existing ASTM standard test methods are not able to reproduce these
requests for evaluating satisfactory corrosion protection of materials in engine coolants. in
this paper, the existing test standard ASTM D 1384 and D 4340 are compared with a complex testing
method using the hot corrosion apparatus (MHTA), which meets practical demands. The MHTA is part
of the test guideline FVV 530-2005 approved by the German automotive and chemical industry. The
different test methods are described and compared. The material behavior of samples tested with
MHTA is discussed based on selected results in some coolants with traditional silicate or organic
acid technologies for corrosion inhibition. Further, the effects of coolant flow and its
influence of deposits as well as the effects of higher temperature loads on samples of aluminum
are shown. 
corrosion; coolant; testing; inhibition