The aging behavior of homogenized type 308 and 308CRE stainless steel

Journal Article · Wed Jul 01 00:00:00 EDT 1987 · Metall. Trans., A; (United States)

DOI:https://doi.org/10.1007/BF02647189· OSTI ID:7202777

Vitek, J M; David, S A

The aging behavior of type 308 stainless steel and type 308 stainless steel with controlled residual elements (308CRE) was studied. The alloys were initially homogenized, resulting in a fully austenitic structure in the type 308 alloy and a duplex austenite plus ferrite structure in the type 308CRE alloy. The materials were subsequently aged at 550, 650, 750, an 850/sup 0/C for times up to 10,000 hours. Aging of the type 308 steel resulted in precipitation of chromium-rich M/sub 23/C/sub 6/, primarily along grain boundaries, followed by sigma-phase formation after long aging times (greater than or equal to5000 hours). The aging response of the duplex type 308CRE steel was somewhat more complicated. Although the titanium-rich carbides, nitrides, and sulfides produced during homogenization remained stable during subsequent aging, some additional precipitation was found. G-phase formed within the residual ferrite but eventually redissolved. The ferrite partially dissolved during early aging and later transformed to sigma phase. The sigma-phase formed significantly faster in the aged type 308CRE alloy. The results are summarized in the form of TTT diagrams. A comparison is made with a similar aging study on the same alloys but starting with the as-welded condition.

• Research Organization: Metals and Ceramics Div., Oak Ridge National Lab., Oak Ridge, TN (US)
• OSTI ID: 7202777
• Journal Information: Metall. Trans., A; (United States), Journal Name: Metall. Trans., A; (United States) Vol. 18A:7; ISSN MTTAB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101* -- Metals & Alloys-- Preparation & Fabrication
360102 -- Metals & Alloys-- Structure & Phase Studies
AGE HARDENING
ALLOYS
AUSTENITIC STEELS
CARBIDES
CARBON ADDITIONS
CARBON COMPOUNDS
CHALCOGENIDES
CHROMIUM ALLOYS
CHROMIUM STEELS
CHROMIUM-NICKEL STEELS
CORROSION RESISTANT ALLOYS
CRYSTAL STRUCTURE
FERRITE
FERRITIC STEELS
GRAIN BOUNDARIES
HARDENING
IRON ALLOYS
IRON BASE ALLOYS
MICROSTRUCTURE
NICKEL ALLOYS
NITRIDES
NITROGEN COMPOUNDS
PHASE STUDIES
PNICTIDES
PRECIPITATION
PRECIPITATION HARDENING
SEPARATION PROCESSES
STAINLESS STEEL-308
STAINLESS STEELS
STEELS
STRUCTURAL CHEMICAL ANALYSIS
SULFIDES
SULFUR COMPOUNDS
TITANIUM CARBIDES
TITANIUM COMPOUNDS
TITANIUM NITRIDES
TITANIUM SULFIDES
TRANSITION ELEMENT COMPOUNDS
VERY HIGH TEMPERATURE