The industry bristle material of choice for brush seals has been the cobalt-based alloy Haynes®25 (also known as L605) for over 30 years. Haynes®25 has excellent oxidation resistance and wear properties in brush seal applications up to temperature of 620°C [1148°F]. Above this temperature creep resistance becomes undesirable for brush seal bristles and has lead to alternative sealing solutions to be implemented in these turbine locations. Nickel-based alloys have been explored as an alternative for Haynes®25 but have been shown to gall badly and wear quickly in comparison.

As increases in turbine performance have resulted in an increase in operating temperatures, it has lead to a need to find a bristle material that performs at temperatures above the limitation of Haynes®25. Initial experimental data has been obtained for a new cobalt-based alloy that shows potential for use as a bristle material at temperatures above 620°C [1148°F]. Further experimental results also indicate that the material appears to have better wear characteristics than Haynes®25 and may prove to be a feasible alternative in some cases.

This paper outlines a material selection process for brush seals, along with development of the alloy for use within brush seals and details of the comparative testing carried out at Cross Manufacturing Company.

This content is only available via PDF.
You do not currently have access to this content.