Journal of Failure Analysis and Prevention

, Volume 12, Issue 3, pp 314–317 | Cite as

Turbine Shroud Cracking Investigation and Repair

Technical Article---Peer-Reviewed

Abstract

Outer shroud segments fabricated from a cast 310 stainless steel were found to have cracked following extended service. Several of these cracked shrouds were sent to the GE-Poland Materials Laboratory for metallurgical investigation with a view to determine the cause of cracking. Detailed investigation revealed cracking to be associated with a sigma phase, a brittle TCP intermetallic, which had developed over time during engine operation. Initial attempts to weld repair the cracks proved unsuccessful as cracks were discovered both during and after the weld repair procedure. A new weld repair procedure incorporating a pre-weld solution annealing heat treatment to remove the sigma phase before welding was successfully developed, thus alleviating the cracking concern.

Keywords

Sigma phase Turbine Shroud 310 stainless steel Weld repair 

Notes

Acknowledgment

The authors would like to acknowledge to Dorota Szczesniak for aiding in publishing this article.

References

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    ASTM E 407-99: Standard Practice for Microetching Metals and Alloys (1999)Google Scholar

Copyright information

© ASM International 2011

Authors and Affiliations

  1. 1.Materials & Process Engineering Department GE AviationWarsawPoland

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