Long-term embrittlement of cast duplex stainless steels in LWR systems: Semiannual report, April--September 1987

Technical Report · Tue Aug 01 04:00:00 EDT 1989

OSTI ID:5685276

Chopra, O K; Chung, H M

This progress report summarizes work performed by Argonne National Laboratory on long-term embrittlement of cast duplex stainless steels in LWR systems during the six months from April to September 1987. Microstructural studies were conducted to investigate the kinetics of spinodal decomposition and G-phase and /gamma//sub 2/ precipitation of CF-8 and CF-8M grades of cast stainless steel. The results indicate that the presence of Mo in CF-8M steel accelerates spinodal decomposition as well as G-phase and /gamma//sub 2/ precipitation. Examination of the long-term-aged CF-8M steels also revealed a ''spinodal-like'' decomposition of the austenite caused by segregation of Fe and Ni in the matrix. Preliminary results indicate that local regions of austenite are significantly hardened by the decomposition. Charpy-impact, tensile, and J-R curve data are presented for several heats of cast stainless steels aged at temperatures between 320 and 450/degree/C for times up to 10,000 h. The results indicate that concentrations of carbon and nitrogen in the steel and the ferrite content and spacing are important parameters in controlling low-temperature embrittlement. The existing correlations for estimating the extent and kinetics of embrittlement do not accurately represent the properties of different grades and compositions of cast stainless steel after thermal aging. 36 refs., 24 figs., 5 tabs.

• Research Organization: Nuclear Regulatory Commission, Washington, DC (USA). Div. of Engineering; Argonne National Lab., IL (USA)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 5685276
• Report Number(s): NUREG/CR-4744-Vol.2-No.2; ANL-89/6-Vol.2-No.2; ON: TI89016842
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220200* -- Nuclear Reactor Technology-- Components & Accessories
36 MATERIALS SCIENCE
360103 -- Metals & Alloys-- Mechanical Properties
AGING
ALLOYS
AUSTENITE
CARBON ADDITIONS
CHARPY TEST
CHEMICAL REACTIONS
CRYSTAL STRUCTURE
DATA
DECOMPOSITION
DESTRUCTIVE TESTING
DOCUMENT TYPES
EMBRITTLEMENT
EXPERIMENTAL DATA
FERRIMAGNETIC MATERIALS
FERRITES
HIGH ALLOY STEELS
IMPACT STRENGTH
IMPACT TESTS
INFORMATION
IRON ALLOYS
IRON BASE ALLOYS
IRON COMPOUNDS
MAGNETIC MATERIALS
MATERIALS
MATERIALS TESTING
MECHANICAL PROPERTIES
MECHANICAL TESTS
MICROSTRUCTURE
NUMERICAL DATA
OXYGEN COMPOUNDS
PRECIPITATION
PROGRESS REPORT
REACTOR MATERIALS
REACTORS
SEPARATION PROCESSES
STAINLESS STEELS
STEELS
TESTING
TRANSITION ELEMENT COMPOUNDS
WATER COOLED REACTORS