Liburdi developed and introduced this technology for the industrial gas turbine industry in the early 1980’s.
These specialized heat treatments were designed to restore the original metallurgical properties and strength of turbine blades that had been exposed to long hours at high operating temperatures. The high temperature (Full Solution) heat treatments developed by Liburdi are successful at enabling sets of turbine blades to achieve extended service or a “second life” – hence the terms FSR® and Full Solution Rejuvenation® have been trademarked.
Liburdi is the pioneer in this technology and has developed Rejuvenation heat treat cycles for virtually all of the common turbine blade alloys (eg. IN738, IN939, U500, U520, MarM002, MarM247, N115, N105, N108, A286, GTD111, Rene80), including the new DS directionally solidified cast blades.
During this 30 year history, Liburdi has successfully rejuvenated over 100,000 blades using the proprietary FSR® process, and has a track record of consistently reliable operation of these blades. Recently some suppliers have begun offering recovery heat treatments that reach partial solution temperatures and do not fully recondition the alloy.
The FSR® process goes to higher temperatures to achieve full solution of the alloy and incorporates high pressure HIP and vacuum heat treatments as part of the process. Since FSR® restores the original micro-structure of the alloy, we are able to re-certify each blade set in the same way that new parts are certified. To do this sample material of the same alloy (usually a scrap blade from the same set) is included in all heat treatments that the set receives. The sample material is then metallurgically re-certified by examining the micro-structure and performing creep strength testing (stress rupture bars) which must meet or exceed the original material acceptance Specifictions for new parts.
Sets of blades that are routinely limited to 48,000 hours by the OEM have been able to be reliably operated to 100,000 - 120,000+ hours of service by applying proven FSR® rejuvenation processes at the time of repair.
Only Liburdi has proven FSR® heat treated blades in service for some 20+ years and full service intervals after rejuvenation.