Effects of hydrogen peroxide on intergranular stress corrosion cracking ofstainless steel in high temperature water, (II) Optimization of crack propagation rate measurement system

In order to determine a crack propagation rate of less than 10(-8) mm/s in a 24-hour integrated measurement, major parameters of a coupled system of a constant tension specimen and crack depth measurement, based on potential drop method, have been optimized. Influences of sensor geometry, location f or detecting potential drop and data processing of the ratio of signal to n oise (S/N) were optimized by applying Taguchi's Method. Then a suitable sen sor geometry and data processing method were proposed to get a robust measu rement system with higher sensitivity and lower susceptibility for geometri cal and procedural fluctuations. By applying the optimal crack propagation rate measurement system, it was c onfirmed that a crack propagation rate of 1x10(-8) mm/s can be measured und er a low concentration condition of hydrogen peroxide with less than a 20% error by a 24-hour integrated measurement.