Study On The Preparation Of Glass-Ceramic Coating And Its Corrosion Resistance In Liquid LBE

Liquid heavy metal lead or lead-bismuth eutectic (LBE) has been proposed to actas the coolant for accelerator driven sub-critical system (ADS) which has beingstudied in China. For the special working condition of ADS, such as high temperatureand corrosion of heavy metals, much higher requirements for traditional metalmaterials’ corrosion resistance has been put forward. As a new kind of specialmaterial, glass-ceramic composite material, which possesses the excellent propertiesof glass and ceramic, has good mechanical property, wear-resisting property andcorrosion resistance. Aiming at the above situation, glass-Cr2O3ceramic coating andCrFeAlTiC metal/glass-ceramic layer were respectively prepared by thermal sprayingtechnology and thermal spraying-laser in-suit reaction compound technology in thispaper. Microstructure, composed component and phase composition of the coatingwere analyzed by means of scanning electron microscope (SEM), energy-dispersivespectrometry (EDS), X-ray diffraction (XRD). Interfacial mechanical property,friction and wear properties, corrosion resistance in liquid heavy metal of coatingwere also studied. The research of this paper, which pointed out the direction for thestudy of the structure material in ADS, has some significance to the development ofnuclear power industry in our country. The main research results are as follows:1. The size of homogeneous mixed glass-Cr2O3ceramic composite powder,which was prepared by high temperature sintering and ball milling, was uniform andequiaxed. The surface of glass-95%Cr2O3ceramic coating prepared by usingoxygen-acetylene thermal spraying technique was smooth and compact. It has goodwear resistant property, and the interfacial bonding strength of coating is32.87MPa.2. CrFeAlTiC composite powder with uniform size was prepared by ball millblending and heating bonding. The metal/glass-ceramic layer with high qualitymetallurgical bonded was prepared by thermal spraying-laser in-suit reactioncompound technology. The result showed that the structure of layer generated by laser remelting and laser in-situ reaction is compact. And there were obvious laserremelting area and glass ceramic layer at the cross section. The thickness of thisglass-ceramic layer with better wear-resisting property and interfacial mechanicalproperty is10~30μm.3. The corrosion resistance of glass-Cr2O3ceramic coating in liquid lead underthe temperature of450℃was investigated. It was shown that the element Pbapparently infiltrated into304stainless steel and45#steel after60h, but had notinfiltrated into the coating. Glass-Cr2O3ceramic coating has good corrosion resistanceto liquid lead.4. The corrosion resistance of metal/glass-ceramic layer and304stainless steel inliquid LBE under the temperature of450℃was studied. The comparative analysisresults showed that304stainless steel, which was immersed in the stagnant LBE for120h, has been eroded by corrosive medium element. While the metal/glass-ceramiccoating has good corrosion resistance performance to the liquid LBE, and it canprevent the elements Pb and Bi infiltrating into the base material. The CrFeAlTiCmetal/glass-ceramic coating can well protect the substrate from being eroded.