RB211 Component Repair Services

A key differentiator at Rolls Wood Group is the extensive component repair services we have to offer. This has enabled RWG to develop over 1,500 unique repair schemes all designed to reduce the cost of ownership by the refurbishment of parts which would otherwise be deemed to be reject. A particular achievement has been the establishment of a turbine blade repair cell which has delivered considerable savings to operators through part rejuvenation and extended blade life.

RB211 Blade Refurbishment

Turbine blades frequently need to be refurbished as a result of service conditions leading to problems such as wear on interlocks and abutment faces, thermal erosion, untwist and corrosion.

Blade features addressed include recovering the interlock/outer platform profiles, re- establishing seal fins, recovering any ‘blade lean’(a specialist repair exclusive to RWG), the unblocking of cooling slots/holes using advanced Electrical Discharge Machining (EDM) techniques and surface preparation/re- protection (using aluminide diffusion and platinum/aluminide type coatings).

All blades are then subjected to our long established proprietary recovery process which is used to fully recover microstructures back to the ‘as-new’ condition.

The latest advanced proprietary weld repair technique offered by Rolls Wood Group uses special alloys with much improved high temperature strength and oxidation resistance which has resulted in significant increases in time between overhauls (TBO) for engines used in hostile environments. Welds and protective coatings applied to turbine blades are subject to rigorous microstructural quality checks. This ensures that current yield rates are in excess of 99%.

RB211 Blade Refurbishment

Blade Refurbishment: EC&T Division have been refurbishing the Rolls-Royce RB211 fleet since 2003. Customers have been benefitting from our refurbishment process which includes recovery of seal fins and interlock/outer platform profiles, microstructural recovery and surface preparation/re-protection using advanced coatings.

Interlock/Outer Platform Recovery

Our OEM approved latest hardfacing interlock material has been proven to consistently deliver superior performance and significant increases in time between overhauls (TBO) for engines used in all fields of operation. It delivers excellent erosion and oxidation resistance characteristics by using optimised Ta+Al+Cr contents with no Ti additions. W, Hf, Ta & Re high melting point elements are used which are considered to be the most effective strengthening additions for these types of applications. This material is designed to be applied easily using conventional techniques with a yield rate of >99%. After a 30,000h service cycle, the two centre figures show the asreceived condition of previous generation material compared to the latest generation material (bottom figure). No erosion or oxidation damage is evident.

Microstructural Recovery

Our proprietary Recovery Heat Treatment Process is used to fully recover turbine blades microstructures back to the ‘zero-hour’ condition. This service is considered to be vital to the refurbishment process and is carried out as standard on turbine blades. RWG has a long track record of microstructural recovery and has the largest number of blade sets worldwide with more than 100,000 hours. The microstructural recovery process is monitored by using stringent OEM microstructural overheat and creep void assessments.

Advanced Coatings

Surface protection of turbine blades is key to reducing repair costs, keeping downtime to a minimum and allowing turbines to operate more efficiently. ECT Division uses the latest OEM approved advanced aluminide and platinummodified aluminide coatings to protect blades against high temperature hot corrosion and oxidation.