The picture showed an example. Since that time these cracks have been removed.
It had not been easy to get rid off cracks located in such places like the egdes of blade groove. To do it, a special cutting tools were needed.
I am not a machining specialist but I have dealt with various machining issues and that is why I managed to create the cutting tools and proper machining technology to get rotors free of cracks.
Below, is a cut section of blade groove.
The shape in the edge 9 and 7 is what we got after machining. A lack of cracks was confirmed by NDE.The cutting tools, we used :
The two pictures above show the tool used in first step of machining. To get shape from the first drawing the next tool was necessary
It is almost impossible to take pictures showing what is the blade groove geometry right now, anyway the machining path is visible and the rest is the same like on the drawing on the top of this post
