CFM56-7B WTT Meeting - September,25-26/2002 CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 1 Booster Vane Corrosion Fan Stator Module CFM56-7B WTT Meeting - September,25-26/2002 CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 2 Background Several reported cases where steel booster vanes were found with pitting corrosion marks – Heavy corrosion marks outside of current AMM/ESM limits – Other CFM56 engine models affected Engineering assessment Root cause investigation - Completed – Booster vane material 17-4PH is sensitive to corrosion Specific saline operation environment is an aggravating factor Potential impact on booster vane durability – Calculations predict a risk to initiate a crack from pits then propagate in HCF mode into base material – No concern in-service No crack finding reported to date Outer shroud attachment area (bolt holes) is most critical area Service Evaluation on-going on a CFM56-3 to better assess progression of pitting corrosion phenomenon during engine operation - No findings to date Fan Stator Module Booster Vane Corrosion CFM56-7B WTT Meeting - September,25-26/2002 CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 3 1 mm VVisisuuaallCCoonnddititioionnooffBBoooosstteerrVVaanneeOOuutteerrSShhrroouuddEExxtteerrnnaallSSuurrffaaccee Fan Stator Module Booster Vane Corrosion CFM56-7B WTT Meeting - September,25-26/2002 CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 4 VVisisuuaallCCoonnddititioionnooffBBoooosstteerrVVaanneeAAirirffooililTTrraailiilninggEEddggee Fan Stator Module Booster Vane Corrosion CFM56-7B WTT Meeting - September,25-26/2002 CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 5 Corrective Action Plan New serviceable limits being implemented in the AMM, and ESM – AMM Limits Any amount of surface oxidation, pitting or corrosion marks on Stage 1, 2, 3, and 4 Booster vanes is permitted. – ESM Limits At module Level » Any amount of surface oxidation, pitting or corrosion marks on Stage 1, 2, 3, and 4 Booster vanes is permitted. At piece part level » Stage 1, 2, 3, and 4 Booster vanes outer & Inner shrouds. Any number if less than 0.02” (0,5 mm) Max. Length. » Stage 1, 2, 3, and 4 Booster vanes outer & Inner shrouds welds. Any number if less than 0.008” (0,2 mm) Max. Length. » Stage 1, 2, 3, and 4 Booster vanes airfoils. Any number if less than 0.012” (0,3 mm) Max. Length. Fan Stator Module Booster Vane Corrosion CFM56-7B WTT Meeting - September,25-26/2002 CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 6 Corrective Action Plan (cont’d) Rework under study – Addition of a protective paint, or passivation Request certification configuration modification Service Evaluation on-going on CFM56-3 engine Expected to be available 1Q 2003 Fan Stator Module Booster Vane Corrosion作者: kinran 时间: 2011-6-4 22:35:04
