Accession Number:

ADA359197

Title:

Spray Formed Ni-Cr Alloys for Shipboard Waste Incinerators

Descriptive Note:

Research and development

Corporate Author:

NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD SURVIVABILITY STRUCTURES AND MATERIALS DIRECTORATE

Report Date:

1998-10-01

Pagination or Media Count:

21.0

Abstract:

The Naval Surface Warfare Center, Carderock Division, NSWCCD has produced several spray formed Ni-Cr alloys in a research effort to identify a replacement for conventionally processed Alloy 690 60Ni-30Cr-9.5Fe waste incinerator liners. Six alloys with chromium contents ranging from 37 to 50 weight percent were chosen for evaluation 61.5Ni-37Cr-1.5Nb, 55.5Ni-43Cr-1.5Zr, 55.5Ni-43Cr-1.5Nb, Alloy 671 52Ni-48Cr, 48.5Ni-50Cr-1.5Nb, and 50Ni-50. These spray formed materials were characterized microstructurally and evaluated for strength, ductility, and hot workability. These measurements were compared with both conventional and spray formed Alloy 690 values. Room and high temperature tensile properties showed that as-sprayed Ni-Cr alloys with chromium contents of 43 or greater exhibited mechanical properties that were equivalent to or better than typical values for wrought Alloy 690. This has identified these materials as candidates for corrosion testing and possible replacement of Alloy 690. It is expected that higher chromium contents will improve corrosion resistance. Hot rolling of the spray formed high chromium alloys was performed easily under laboratory conditions, showing that these alloys in the spray formed condition can endure post processing without brittle cracking problems. This hot working improved the mechanical properties to values that exceeded their conventional wrought counterparts for both strength and ductility. This shows that any of the alloys in their spray formed and hot worked condition can be considered as possible replacements for Alloy 690, and should be subjected to corrosion tests.

Subject Categories:

  • Properties of Metals and Alloys
  • Marine Engineering

Distribution Statement:

APPROVED FOR PUBLIC RELEASE