Process for stabilizing dimensions of duplex stainless steels for service at elevated temperatures

Patent · Tue Apr 21 00:00:00 EST 1981

OSTI ID:6346931

Hull, F C; Tobin, J C

Duplex stainless steel materials containing austenite plus delta ferrite, are dimensionally stabilized by heating the material to a reaction temperature between about 1050/sup 0/-1450/sup 0/ F. (566/sup 0/-788/sup 0/ C.), holding it at this temperature during transformation of delta ferrite to austenite plus sigma phase, and subsequently heating to a reversion temperature between about 1625/sup 0/-1750/sup 0/ F. (885/sup 0/-954/sup 0/ C.), whereby the sigma phase transforms back to ferrite, but the austenite remains dispersed in the ferrite phase. Final controlled cooling permits transformation of ferrite to austenite plus sigma and, later, precipitation of carbides.

• Assignee: Dept. of Energy
• Patent Number(s): US 4263063
• Application Number: TRN: 81-015191
• OSTI ID: 6346931
• Resource Relation: Patent File Date: Filed date 5 Jul 1979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AUSTENITIC STEELS
FABRICATION
STAINLESS STEELS
STABILIZATION
AUSTENITE
FERRITE
HEAT TREATMENTS
IRON-DELTA
MICROSTRUCTURE
PRECIPITATION
VERY HIGH TEMPERATURE
ALLOYS
CARBON ADDITIONS
CHROMIUM ALLOYS
CORROSION RESISTANT ALLOYS
CRYSTAL STRUCTURE
ELEMENTS
IRON
IRON ALLOYS
IRON BASE ALLOYS
METALS
SEPARATION PROCESSES
STEELS
TRANSITION ELEMENTS
360101* - Metals & Alloys- Preparation & Fabrication