EFFECT OF VARIOUS ANNEALING CYCLES ON INCONEL 718 MICROSTRUCTURE

Abstract

Metallographic studies were performed to investigate the effect of various annealing cycles on grain size and precipitate morphology in Inconel 718 nickel chromium alloy. Before and after aging, the DPH hardness of all material was determined and photomicrographs at 250X and 2000X were prepared. Annealing temperatures of 1500 and 1600F failed to produce satisfactory results. Annealing between 1700 and 1800F adequately dissolves precipitated phases so that subsequent aging produces maximum hardness. Annealing overaged material at 1900F for 15 minutes appears to completely dissolve precipitate phases without altering precipitation behavior during subsequent aging or encouraging excessive grain growth. When annealed at temperatures greater than 1900F, excessive grain growth can be expected. Precipitation behavior during subsequent aging also appears different with grain boundary films forming.

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Document Details

Document Type
Technical Report
Publication Date
Mar 10, 1964
Accession Number
AD0431618

Entities

People

  • R. Newcomer

Organizations

  • McDonnell Aircraft Corporation

Tags

Communities of Interest

  • C4I

DTIC Thesaurus Topics

  • Air Cooled
  • Air Force
  • Alloys
  • Annealing
  • Chromium
  • Chromium Alloys
  • Grain Boundaries
  • Grain Growth
  • Grain Size
  • Hardness
  • Heat Treatment
  • Materials
  • Mechanical Properties
  • Missouri
  • Precipitates
  • Precipitation
  • United States

Fields of Study

  • Materials science

Readers

  • Groundwater Contamination Remediation.
  • Materials Science and Engineering.
  • Metallurgy