Accession Number : AD0778944

Title :   Research on High Temperature Strength Nickel Base Alloys with Superior Oxidation Resistance.

Descriptive Note : Final rept. Mar 71-Feb 73,


Personal Author(s) : Kvernes,Ingard ; Kofstad,Per

Report Date : DEC 1973

Pagination or Media Count : 46

Abstract : The properties of cyclic furnace oxidation and hot corrosion were studied on Ni-9Cr-6Al-(0.02-0.1)Y alloys. Samples of both as cast and wrought structures were used. Continuous weight gain measurements and detailed structural analyses were conducted. Tests in 1 atm. air up to 1000 hrs at 1000C show no spallation. At 1200C, however, spallation is occurring in addition to losses in the total weight after an initial period. A pretreatment in dry H2 (the partial pressure of O2 must be below the dissociation pressure for Cr2O3) is shown to reduce these effects. A mechanism for the process is proposed and discussed. Hot corrosion tests in combustion gases have been conducted mainly at 950C. Metallographic analyses of corroded samples show a catastrophic degradation of the samples by sulfidation and oxidation reactions. A coating of CeO2 or Al2O3 seems to be protective against combustion gases and reduces completely the internal oxidation and sulfidation attacks at 950C. (Author)

Descriptors :   *Nickel alloys, High temperature, High strength alloys, Alloys, Oxidation resistance, Corrosion, Heat, Structural properties, Protective coatings, Chromium alloys, Aluminum alloys, Norway

Subject Categories : Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE