Abstract
In the cooling water of the marine diesel engine, Chromate Additives for the purpose of preventing the corrosion have been used without trouble. But recently they are regulated by the law on the water pollution.
Though Nitrates are generally adopted instead of Chromates, they have also the following problems. i.e. the piston crown crack and the deterioration of the cooling water character.
With the progress of the diesel engine performance, the water cooled piston, the cylinder cover and the cylinder liner are receiving more heat and power stress. The suitability of the anticorrosion will control the reliability and the durability of diesel engines.
The static method of testing the anticorrosive effect in the laboratory (soak test pieces in compounding water, settle in the constant temperature bath and survey the corrosive condition) and the method of JIS K2234 are unable to solve various problems, and we have been feeling keenly the necessity of the dynamic method drawing to the actual service. The big experiment plants don't suit to be operated in the laboratory and handy testing apparatus have not been on the market, so we produced a testing apparatus which answers these purposes and got good result. We introduce the abstract of the experiment.
