Hello, what kind of Cracks are you seeing and where are they located?
Can you determine if the cracks are due to high stresses, FOD (object damage), or rubbing against the casing?
Some inspection tips:
-Verify is there are corrosion on the spring washers, bushings
-verify proper X gaps (check for rolled metal or casing rubs)
-direction of IGV
-verify proper IGV angles between upper and lower case break and with each individual vane (rack and pinion might be off)
-if its FOD, might want to inspect your inlet system/duct on where the foreign matter is coming from
-is your anti-icing Bleed heat system working? any signs of icing causing the IGV cracks?

There are many vendors that have a metallurgical background that can inspect your cracks to determine where the point of propogation and cyclic fatigue is from. However they are usually not familar with the entire IGV system and its operating purpose.. You can try companies like PSM (Power System. Manuf.) or Pratt and Whitney for some answers if you are looking for a non OEM disposition. I know they have a strong engineering background and might offer IGV replacement blades.
good luck.
Regards,
RStevens