Accession Number : AD0268718

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

Corporate Author : MICHIGAN UNIV ANN ARBOR

Personal Author(s) : GLUCK,JEREMY V. ; FREEMAN,JAMES W.

Report Date : SEP 1961

Pagination or Media Count : 1

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)

Descriptors :   *CHROMIUM ALLOYS, *MOLYBDENUM ALLOYS, *NICKEL ALLOYS, ALLOYS, CREEP, ELECTRON MICROSCOPY, FRACTURE (MECHANICS), GRAIN STRUCTURES (METALLURGY), HARDNESS, HEAT RESISTANT METALS + ALLOYS, HIGH TEMPERATURE, IMPACT SHOCK, MECHANICAL PROPERTIES, MICROSTRUCTURE, STRESSES, TENSILE PROPERTIES, TEST METHODS, TITANIUM ALLOYS, X RAY DIFFRACTION, ZIRCONIUM ALLOYS

Distribution Statement : APPROVED FOR PUBLIC RELEASE