The Development and Production of a Functionally Graded Composite for Pb-Bi Service

Ballinger, Ronald G

关键词: ALLOYS;    COOLANTS;    CORROSION;    CORROSION RESISTANCE;    DESIGN;    DIFFUSION;    ELECTROCHEMICAL CORROSION;    EUTECTICS;    FAST REACTORS;    HEAT AFFECTED ZONE;    HEAT TREATMENTS;    PERFORMANCE;    POWER DENSITY;    PRODUCTION;    RADIATIONS;    VELOCITY;    WELDABILITY Lead-Cooled Reactor;    Functionally Graded Composite;    Corrosion Resistance;   

DOI  :  10.2172/1021169
RP-ID  :  DOE-ID14742
PID  :  OSTI ID: 1021169
Others  :  TRN: US201118%%778

美国|英语

来源: SciTech Connect

【 摘 要 】

A material that resists lead-bismuth eutectic (LBE) attack and retains its strength at 700?��C would be an enabling technology for LBE-cooled reactors. No single alloy currently exists that can economically meet the required performance criteria of high strength and corrosion resistance. A Functionally Graded Composite (FGC) was developed with layers engineered to perform these functions. F91 was chosen as the structural layer of the composite for its strength and radiation resistance. Fe-12Cr-2Si, an alloy developed from previous work in the Fe-Cr-Si system, was chosen as the corrosion-resistant cladding layer because of its chemical similarity to F91 and its superior corrosion resistance in both oxidizing and reducing environments. Fe-12Cr-2Si experienced minimal corrosion due to its self-passivation in oxidizing and reducing environments. Extrapolated corrosion rates are below one micron per year at 700???��C. Corrosion of F91 was faster, but predictable and manageable. Diffusion studies showed that 17 microns of the cladding layer will be diffusionally diluted during the three year life of fuel cladding. 33 microns must be accounted for during the sixty year life of coolant piping. 5 cm coolant piping and 6.35 mm fuel cladding preforms were produced on a commercial scale by weld-overlaying Fe-12Cr-2Si onto F91 billets and co-extruding them. An ASME certified weld was performed followed by the prescribed quench-and-tempering heat treatment for F91. A minimal heat affected zone was observed, demonstrating field weldability. Finally, corrosion tests were performed on the fabricated FGC at 700???��C after completely breaching the cladding in a small area to induce galvanic corrosion at the interface. None was observed. This FGC has significant impacts on LBE reactor design. The increases in outlet temperature and coolant velocity allow a large increase in power density, leading to either a smaller core for the same power rating or more power output for the same size core. This FGC represents an enabling technology for LBE cooled fast reactors.