2013 Volume 62 Issue 10 Pages 377-382
About copper localized corrosion water factor, clear-cut decisions was conventionally difficult in addition to corrosion specialists. The hole which can be judged from a calculation result to anyone now - the number of forefingers is shown. Furthermore, it is possible by using Nakajima Diagram to judge the corrosion Risk of water quality, the propriety of past water quality, etc. also by non-experts of corrosion. This was confirmed employing copper I type pitting corrosion 4 example and healthy 2 examples in a cooling-water system. Furthermore, the proposal and efficacy of improvements index in water quality： WQII（improvements index in water quality）which can judge the propriety of the present water quality management simple were shown.