08256 Localized Corrosion of a Super-Austenitic Stainless Steel (Fe-24Ni-20Cr-6.3Mo-0.22N) Brazed with a Ni-based braze (Ni-22Cr-6.3Si-3.8P): Effect of Braze Clearance on Corrosion Resistance

Available for download

Product Number: 51300-08256-SG

ISBN: 08256 2008 CP

Author: Joshua James, John Scully, and Jim Fitz-Gerald

Publication Date: 2008

Member Price: $0.00

Non Member Price: $20.00

Price: $20.00

Qty:

The microstructural and local corrosion characteristics of a super-austenitic stainless steel (SASS), (Fe-24Ni-20.5Cr-6.3Mo-0.22N, UNS N08367), brazed with a commercially available Ni-based filler alloy, (Ni-22Cr-6.5Si-3.5P) are investigated. The isolated SASS base material is intrinsically resistant to pitting and crevice corrosion in 0.6 M NaCl solution at room temperature. Isolated braze alloy, tested as a bead prepared at 1150 °C for 60 minutes in a vacuum furnace, without the diffusive egress of melting point depressants (MPDs) exhibited critical potentials for localized corrosion in 0.6 M NaCl well below that of the SASS. This is due to both the low pitting resistance equivalency number (PREN) of the Ni-Cr solid solution and the loss of beneficial Cr due to formation of silicide and phosphide phases, enabled by the presence of these MPDs.