Stable phases in aged type 321 stainless steel
X-ray diffraction and Analytical Electron Microscopy have been used to characterize the precipitate phases present in type 321 stainless steel after 17 years of service at approximately 600/sup 0/C. The morphology, crystallography, and orientation relationships with the matrix of the precipitates have been determined along with the chemical composition of several of the phases. Long-term aging of type 321 stainless steel indicates TiC, not M/sub 23/C/sub 6/, is the stable carbide phase. A theory is developed to explain appearance of M/sub 23/C/sub 6/ at intermediate times. The theory also indicates the means for preventing M/sub 23/C/sub 6/ formation and hence sensitization of the steel to intergranular corrosion. The amount of sigma found correlates well with results from shorter time studies. Ti/sub 4/C/sub 2/S/sub 2/ and a complex phosphide-arsenide were also present.
- Research Organization:
- Oak Ridge National Lab., TN (USA)
- DOE Contract Number:
- W-7405-ENG-26
- OSTI ID:
- 6665464
- Report Number(s):
- CONF-780213-13
- Resource Relation:
- Conference: 107. AIME meeting, Denver, CO, USA, 26 Feb 1978
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
STAINLESS STEEL-321
PHASE STUDIES
CHEMICAL COMPOSITION
HIGH TEMPERATURE
INTERGRANULAR CORROSION
PRECIPITATION
TITANIUM CARBIDES
ALLOYS
CARBIDES
CARBON COMPOUNDS
CHEMICAL REACTIONS
CHROMIUM ALLOYS
CHROMIUM STEELS
CHROMIUM-NICKEL STEELS
CORROSION
CORROSION RESISTANT ALLOYS
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
IRON ALLOYS
IRON BASE ALLOYS
MATERIALS
NICKEL ALLOYS
SEPARATION PROCESSES
STAINLESS STEELS
STEELS
TITANIUM ADDITIONS
TITANIUM ALLOYS
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
360102* - Metals & Alloys- Structure & Phase Studies