There were several turbine failures on Czech coal power plants in last few years. These failures were usually caused by a crack initiation and propagation through turbine blades. The majority of these failures have occurred in the low-pressure part of steam turbine on so-called Wilson line where the first condensation of steam takes place.

In first part of our experimental program we tested original material the 12% Chromium steels Ak1Td and Ak1Ni used for the turbine blades in our country to find the condition of crack initiation and propagation. In second part the possibility of replacing the original material by Titanium alloy Ti-6Al-4V was evaluated. The slow strain rate tests, stress corrosion cracking tests and corrosion fatigue tests with 1/2 CT (Compact Tension) specimen were carried out in solutions with various concentration of dissolved oxygen, NaCl and other components( F^-, HCl,CH₃COOH). We also tried to develop a computer program for simulation of crack propagation in various phases of crack growth on turbine blades .The sensitivity to local corrosion was find as a main reason of crack initiation. The tests with Titanium alloy Ti-6Al-4V are under way. In future we are planning to carry out some electrochemical measurements of galvanic corrosion and crevice corrosion susceptibility of Titanium blades in connection with the turbine casting.