Root-Cause Analysis When the Same Hot-Gas-Path Part Keeps Failing

Ask for RCFA when the same row fails twice, when a newly installed aftermarket or OEM part fails early, when a cracked liner arrives together with a bad temperature spread, or when insurance or a dispute needs a cause. Do not send every worn tip to the lab. That only delays the outage.

A tip rub found once, on one serial, with a clean root, is a weld-or-blend decision. Send photographs and hours. Euroturbine writes a workscope. Do not wait three weeks for a fracture report on a blade that will clearly restore. That only slips the outage.

The same crack on the same row at two or three outages. A newly installed blade — aftermarket or OEM — that fails in the first interval. A cracked liner that arrives with a bad exhaust-temperature spread. Insurance or a commercial dispute that needs a named cause. Case: a combined-cycle V94.2, first-stage vanes cracked near the inner shroud at two successive openings. Welding the vanes again without looking at burners and temperature spread buys the third opening. Euroturbine asks for the failed metal, hours, starts, last fuel, last wash, and whether sister rows failed the same way.

Three things, on paper. First, a cause you can test — not “کیفیت پایین”. Example: uneven combustion, blocked cooling, wrong coating for this fuel, or a geometry error on a reverse-engineered row. Second, the evidence: fracture marks, metallography, the operating diary. Third, one corrective action: tune the burners, change the coating stack, clear the holes, or change the part number. “بیشتر دقت کنید” is not an action. Repair or new-make starts after the cause has a name.

RCFA service · Oxidation and hot corrosion · NDT