Transformations and new PHACOMP analysis in weld metal of Hastelloy C-type alloys. [C-4, C-22, C-276]

Conference · Wed Jan 01 04:00:00 EST 1986

OSTI ID:5602844

Cieslak, M J; Headley, T J; Romig, Jr, A D

The sequence of phase transformations occurring during solidification and cooling of weld metals in the Hastelloy C family (C-4, C-22, C-276) has been determined. An equivalent component chemistry model has been defined for these alloys which allows existing Ni-Cr-Mo ternary phase diagrams to be used to predict the transformation sequence (both liquid ..-->.. solid and solid ..-->.. solid) in these complex alloys. In the cases of Alloys C-22 and C-276, the solidification events terminate with the formation of a constituent containing a topologically-close-packed (TCP) phase (sigma in C-22; P in C-276). The New PHACOMP formalism developed by Morinaga et al. for predicting TCP phase precipitation by solid state transformation in superalloys is applied for the first time to measured weld solidification segregation profiles. This formalism correctly predicts the occurrence of terminal solidification TCP phases in Alloys C-22 and C-276 and correctly predicts the absence of such phases as terminal solidification products in Alloy C-4. Implications to analysis of other nickel alloy weld metals are suggested.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 5602844
• Report Number(s): SAND-85-1586C; CONF-860594-5; ON: DE86011422
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
ALLOYS
CHEMICAL ANALYSIS
CHROMIUM ALLOYS
ELECTRON MICROPROBE ANALYSIS
FABRICATION
HASTELLOY C
HASTELLOYS
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
IRON ALLOYS
JOINING
MATERIALS
MICROANALYSIS
MOLYBDENUM ALLOYS
NICKEL ALLOYS
NICKEL BASE ALLOYS
PHASE TRANSFORMATIONS
SOLIDIFICATION
TUNGSTEN ALLOYS
WELDING