EFFECT OF CREEP-EXPOSURE ON MECHANICAL PROPERTIES OF 80NI - 20CR AND TZM MOLYBDENUM ALLOYS

Abstract

An investigation was made of the influence of creep-exposure at 1000 to 1800 F on mechanical properties of a structurally stable 80Ni - 20Cr alloy. Strain hardening and residual stresses raised strength and lowered ductility for creep at the lower temperatures. With increasing temperature of creep, this factor diminished. Internal microcracking in the grain boundaries occurred increasingly with exposure temperature and creep strain. A large amount of microcracking was required to reduce ductility and, when more severe, to reduce ultimate tensile strength. Two grain sizes were investigated. The fine grained material was less damaged by cracking than the coarse grain material for a given exposure. It was, however, subject to grain growth at intermediate temperatures with a loss in strength. This indicated that internal cracking had to be extensive for appreciable damage. This is due to the low strength and high ductility of the alloy. (Author)

Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1961
Accession Number
AD0268718

Entities

People

  • James W. Freeman
  • Jeremy V. Gluck

Organizations

  • University of Michigan

Tags

DTIC Thesaurus Topics

  • Alloys
  • Creep
  • Ductility
  • Fine Grained Materials
  • Grain Boundaries
  • Grain Growth
  • Grain Size
  • Materials
  • Mechanical Properties
  • Molybdenum
  • Molybdenum Alloys
  • Residual Stress
  • Strain Hardening
  • Tensile Strength

Fields of Study

  • Materials science

Readers

  • Materials Science and Engineering.
  • Metallurgy