Modeling Second-Phase Formation during Rapid Resolidification of Stainless Steel Alloys

Conference · Mon Jan 28 04:00:00 EST 1991

OSTI ID:5901576

Elmer, J. W. ^[1]; Eagar, T. W. ^[2]; Allen, S. M. ^[2]

---

1. Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
2. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

Many common stainless steel (SS) alloy microstructures consist of a mixture offerrite and austenite phases, however, when these alloys are rapidly resolidified using laser beam (LB) or electron beam (EB) processes they solidify in the single-phase-austenite orsingle-phase-ferrite mode. This paper investigates the influence of solidification rate on the reduction, and eventual elimination, ofsecond phases during the rapid solidification of SS alloys. The influence ofsolidification rate on the ferrite content ofthese alloys wasstudied by calculating the dendrite-tip undercooling and then incorporating these results into a solute-redistribution model to calculate the relative fractions of primary and secondary phases that solidify from the melt. Single-phase solidification was predicted at high cooling rates and was confirmed through STEM analysis, showing solidification microstructures void of any significant microchemical composition gradients.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE; US Department of the Navy, Office of Naval Research (ONR); USDOD
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5901576
• Report Number(s): UCRL-CR--106146; CONF-9106130--1; ON: DE91008567; CNN: N00014-80-C-0384
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
ALLOYS
AUSTENITE
CARBON ADDITIONS
CHEMICAL COMPOSITION
CHROMIUM ALLOYS
COOLING
CRYSTAL STRUCTURE
ELECTRON BEAM WELDING
FABRICATION
FERRITE
HIGH ALLOY STEELS
INTERFACES
IRON ALLOYS
IRON BASE ALLOYS
JOINING
LASER WELDING
MICROSTRUCTURE
NICKEL ALLOYS
PHASE TRANSFORMATIONS
PHASE VELOCITY
SOLIDIFICATION
SOLUTES
STAINLESS STEELS
STEELS
Stainless steel alloys
TEMPERATURE GRADIENTS
VELOCITY
WELDING
dendrite-tip undercooling
rapid solidification
second-phase formation
single-phase microstructures
solute redistribution