Preliminary Experimental Study Of Compatibility Of High-temperature Resistant Materials With Liquid LiPb

Fusion Energy is a kind of "clean, safe and permanent" energy. Its realization will resolve human energy needs once and for all, and substantially reduce environmental pollution.Issue of materials is one of the "bottleneck" problems of the realization of application of fusion energy. SiC_f / SiC composites, W and Mo are very potential candidates of structural materials and functional materials of important components (such as blanket, first wall, divertor, etc.) of the high-temperature fusion reactors because of their excellent physical properties. At the same time, based on the needs of related technology development of liquid blankets, FDS team has designed and construted series of liquid lithium-lead (LiPb) loops. In order to meet the development of high-temperature LiPb loop, it is in a hurry to find applicative structural materials for the pipes of the loop. 310S stainless steel is choiced as the candidate structural material of the high-temperature LiPb loop because of its excellent high temperature property and high temperature oxidation resistance property. Because all these high temperature resisitant materials are in direct contact with the liquid LiPb, study the compatibility of them with liquid LiPb under different conditions becomes critical.In this thesis, compatibility experiments of SiC ceramic and SiC_f/SiC composites, W, Mo, and 310S stainless steel with LiPb at 700℃¹000℃for different exposing time were carried out in static LiPb corrosion test device of DRAGON-ST. Both DRAGON-ST and high purity LiPb were developed independently by FDS team. The results showed that: 1) The free Si,α-SiC, amorphous SiC of domestic SiC and SiC_f/SiC composites dissolved in LiPb at high temperature which lead poor compatibility of them in liquid LiPb at 700℃¹000℃; 2) Uniform corrosion of W and Mo occurred in the high temperature liquid LiPb. The corrosion depth of W at 700℃for 500h is 0.38 mm·a^-1, and that for 1000h is 0.16 mm·a^-1. The corrosion rate reduced with time, probably mainly due to the solubility of W in the LiPb saturated gradually. The corrosion depth of Mo at 700℃for 500h is 1.96 mm·a^-1, and that at 1000℃for 200h is 2.575 mm·a^-1. The higher the temperature, more serious the corrosion; 3) the compatibility of 310 stainless steel with liquid LiPb is poor. It can not be choiced as structure material of the high temperature liquid LiPb experiment loop at the temperature of working environment up to 700℃for long time.