| Title |
Behavior of Small Crack Growth in Steam Turbine Blade Material |
| Authors |
남승훈(Seung Hoon Nahm); 이주진(Joo Jin Lee); 허용학(Yong hak Huh); 전승범(Seung Bum Joen); 이해무(Hae Moo Lee) |
| Abstract |
In order to evaluate the life of steam turbine blade, information of the crack initiation at corrosion pits and the crack growth is needed. Corrosion pits are made artificially on the specimens machined from the real turbine blades(12% Cr steel) and specimens are tested to study the small crack initiation and growth. Difference between the small cracks and the long cracks is made by the crack growth behavior and the size of small cracks is 700∼800㎛ equivalent to 14∼18 times of grain size. The formation fife of these small cracks reveals 80∼90% of total fatigue life and those life with smaller applied stress shows larger portion of total life than that of larger stress. |