关键词:  , 锆合金；耐腐蚀性能；氧化膜；压应力

Abstract: To investigate the effect of corrosion temperature and water chemistry on compressive stress with the increase of oxide film thickness, Zr4 and N18 tubular specimens were corroded in three kinds of water chemistry. Compressive stress of oxide films formed on the outside of the tubular specimens was measured with a curling method of oxide film. Experimental results indicate that compressive stress in oxide films decreases in the sequence of 360 ℃ deionized water ＞400 ℃ super-heated steam ＞360 ℃ lithiated water. Li+ and OH- ions incorporated into the oxide films decrease the surface free energy of oxide. As a result, the diffusion of vacancies, formation of pores and development of micro-cracks are enhanced. This is the reason why compressive stress of oxide films formed in 360 ℃ lithiated water is the lowest. Diffusion of vacancies is promoted at higher temperature, resulting in relaxation of compressive stress in oxide films. Therefore compressive stress of oxide films formed in 400 ℃ super-heated steam is lower than that formed in 360 ℃ deionized water.