The influence of cooling rate on the ferrite content of stainless steel alloys

Conference · Fri Mar 24 04:00:00 EST 1989

OSTI ID:6117116

Elmer, J. W.; Allen, S. M.; Eagar, T. W.

Electron-beam surface melting was used to rapidly solidify a series of high-purity 59% Fe-Ni-Cr alloys at cooling rates between 7 /degree/C/s and 7.5 /times/ 10/sup 6/ /degree/C/s. The primary solidification mode was identified in each of the resolidified melts using optical metallography; the residual ferrite content was measured using a vibrating sample magnetometer. The cooling rate was shown to dramatically alter the residual ferrite content of these alloys through its influence on the amount of solute redistribution that occurs during solidification and through its subsequent influence on the extent of the solid-state transformation of ferrite. The results show that the solidification mode, cooling rate, and specific alloy composition are equally important, interrelated factors in the prediction of the residual ferrite. The residual ferrite content of primary-austenite solidified alloys decreases with increasing cooling rate whereas the residual ferrite content of primary-ferrite solidified alloys increases with increasing cooling rate. Exceptions to this general behavior occur when: ferrite transforms to austenite by a massive transformation in fully-ferritic-solidified alloys and an alloy changes its mode of solidification from primary-ferrite at low cooling rates to primary-austenite at high cooling rates. 12 refs., 7 figs., 4 tabs.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6117116
• Report Number(s): UCRL-100776; CONF-8905118-1; ON: DE89009966
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101 -- Metals & Alloys-- Preparation & Fabrication
360102* -- Metals & Alloys-- Structure & Phase Studies
360103 -- Metals & Alloys-- Mechanical Properties
ALLOYS
BEAMS
CARBON ADDITIONS
CHEMICAL COMPOSITION
CHROMIUM ALLOYS
COOLING
CRYSTAL STRUCTURE
DIAGRAMS
ELECTRON BEAMS
FERRITE
HIGH ALLOY STEELS
IRON ALLOYS
IRON BASE ALLOYS
LEPTON BEAMS
MICROSTRUCTURE
NICKEL ALLOYS
PARTICLE BEAMS
PHASE DIAGRAMS
PHASE TRANSFORMATIONS
SOLIDIFICATION
STAINLESS STEELS
STEELS