Influence of carbon content and ferrite morphology on the sensitization of duplex stainless steel

Journal Article · Thu May 01 00:00:00 EDT 1980 · Metall. Trans., A; (United States)

DOI:https://doi.org/10.1007/BF02661208· OSTI ID:5271332

Devine, T M

The influence of ferrite morphology and carbon content on the intergranular corrosion behavior of 308 stainless steel was investigated using four wrought alloys and six weld deposited alloys. The four wrought alloys were heat treated at four different annealing temperatures to introduce four different amounts of ferrite. The annealed samples along with the weld deposited alloys were aged at temperatures ranging from 480 to 700/sup 0/C for times varying between 15 min and 1000 h and then tested for intergranular corrosion susceptibility in acidified copper-copper sulfate solution. For a given carbon content there exists a critical amount and distributions of ..cap alpha..-..gamma.. boundary area above which the alloy is immune and below which it is susceptible to intergranular corrosion. For amounts and distribution of ..cap alpha..-..gamma.. boundary area less than the critical value two types of sensitization behavior are possible. First, there may be a sufficient amount and distribution of ..cap alpha..-..gamma.. boundary area to insure rapid healing of the sensitized microstructure. Second, there may be an inadequate amount or distribution of ..cap alpha..-..gamma.. boundary area to produce either immunity or rapid healing and the alloy behaves as a fully austenitic alloy regardless of the amount of ferrite present. A model is presented which describes as a function of carbon content the critical amounts and distributions of ..cap alpha..-..gamma.. boundary area required for rapid healing and immunity to sensitization.

• Research Organization: General Electric Co., Schenectady, NY
• OSTI ID: 5271332
• Journal Information: Metall. Trans., A; (United States), Vol. 11:5
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COPPER SULFATES
CORROSIVE EFFECTS
STAINLESS STEEL-308
INTERGRANULAR CORROSION
MICROSTRUCTURE
ANNEALING
CARBON
FERRITE
HEAT TREATMENTS
MORPHOLOGY
QUANTITY RATIO
ALLOYS
CARBON ADDITIONS
CHEMICAL REACTIONS
CHROMIUM ALLOYS
CHROMIUM STEELS
CHROMIUM-NICKEL STEELS
COPPER COMPOUNDS
CORROSION
CORROSION RESISTANT ALLOYS
CRYSTAL STRUCTURE
ELEMENTS
IRON ALLOYS
IRON BASE ALLOYS
NICKEL ALLOYS
NONMETALS
OXYGEN COMPOUNDS
STAINLESS STEELS
STEELS
SULFATES
SULFUR COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
360105* - Metals & Alloys- Corrosion & Erosion
360102 - Metals & Alloys- Structure & Phase Studies