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Title: Corrosion resistance of inconel 690 to borax, boric acid, and boron nitride at 1100{degrees}C

Technical Report ·
DOI:https://doi.org/10.2172/522764· OSTI ID:522764

Significant general and localized corrosion was observed on Inconel 690 coupons following exposure to borax, boric acid and boron nitride at 1100{degrees}C. Severe localized attack at and below the melt line was observed on coupons exposed to borax. An intergranular attack at and below the melt line was observed on coupons exposed to borax. An intergranular attack (IGA) of the Inconel 690 was also observed. Severe internal void formation and IGA (30 mils penetration after 3 days) was observed in the coupon exposed to boric acid. Both borax and boric acid remove the protective chromium oxide; however, this layer can be reestablished by heating the Inconel 690 to 975 {degrees}C in air for several hours. Inconel 690 in direct contact with boron nitride resulted in the formation of a thick chromium borate layer, a general corrosion rate of 50 to 90 mils per year, and internal void formation of 1 mil per day.

Research Organization:
Savannah River Site (SRS), Aiken, SC (United States)
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
AC09-89SR18035
OSTI ID:
522764
Report Number(s):
WSRC-TR-96-0394; SRT-MTS-96-2054; ON: DE97008654; TRN: 97:005013
Resource Relation:
Other Information: PBD: 12 Dec 1996
Country of Publication:
United States
Language:
English