Title

The effect of micro structural differences on Na2SO4-induced corrosion of superalloy CMSX-4 at high temperatures

Abstract

Single crystal (SC) nickel based superalloys have been used in aero engine applications for a long time. The SC casting techniques are not yet widely used in the land based engine components because of their much lager size which makes casting and the subsequent heat treatment more difficult, In large casting, microporosity and elemental segregation are more seven. The γ/'γ' eutectic structure and dendritic arm spacing are also larger to large casting size.All these defects will affect the heat treatment process and the subsequent service properties, including the resistance to oxidation and hot corrosion. In this work, as-cast and heat treated CMSX-4 specimens from small and large blades were used to study the effects of cast defects and heat treatment on Na2SO4-induced hot corrosion resistance of the single crystal superalloy. The tests were carried out between 900 to 1000°C, for times ranging from 10 to 600 hours in the presence of a Na2SO4deposit. The specimens from as-cast large blade underwent catastrophic attack after a short exposure time. But the initiation time for catastrophic attack approximately doubled in the case of wholly solution heat treated specimens. It is thus likely that although the hot corrosion resistance of this single crystal material is not as good as that of IN738, proper heat treatment can improve its hot corrosion resistance.

Publication Date

1-1-1997

Publication Title

Proceedings of the ASME Turbo Expo

Volume

4

Document Type

Article; Proceedings Paper

Personal Identifier

scopus

DOI Link

https://doi.org/10.1115/97-GT-424

Socpus ID

84973597811 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/84973597811

This document is currently not available here.

Share

COinS