ISSN: 1945-7553
CODEN: JTEVAB
Page Count: 7

Phase Analysis of Standard and Molybdenum-Modified Mar-M509 Superalloys

Bišs, V
Senior research associateMember of ASTM, Climax Molybdenum Co. of Michigan, Ann Arbor, Mich.

Abstract

Phase characterization studies have been conducted by an ASTM Task Group on interlaboratory specimens of three Mar-M509-type superalloys heat treated to simulate service conditions. The results of the studies, employing X-ray and electron diffraction analysis and energy dispersive X-ray analysis, showed that the alloys contain (a) script-type metal-carbon (MC) carbides, (b) two types of eutectics (both containing M₂₃C₆-type carbides), (c) M₂₃C₆ carbides precipitated in the vicinity of script-type MC carbides and M₂₃C₆ eutectics, and (d) very fine MC carbides precipitated along crystallographic planes of the matrix phase. The molybdenum-modified Alloys XC-224 and XC-224Fe also contain M₆C carbides. The compositional and crystallographic data for the phases are presented and discussed.

Keywords:
solid phases, cobalt alloys, molybdenum containing alloys

Paper ID: JTE11640J
DOI: 10.1520/JTE11640J
ASTM International is a member of CrossRef.