在Zr-4合金成分的基础上添加42-140μg/g硫制备成试验合金,采用高压釜腐蚀试验研究了添加微量硫对Zr-4合金在360℃/18.6MPa的0.01mol/L LiOH水溶液中耐蚀性的影响;采用TEM,EDS和SEM观察和分析了合金和合金腐蚀后氧化膜的显微组织。结果表明,添加微量的硫提高了Zr-4合金在360℃/18。6MPa的0.01mol/L LiOH水溶液中的耐蚀性,且随着硫含量的增加对耐蚀性的改善作用越明显。在制备的含硫锆合金中,固溶在合金α-zr基体中的硫含量小于140μg/g,多余的硫以四方结构的zr-S2相析出。微量硫的添加,可以有效地延缓氧化膜中孔隙和裂纹的形成以及Zr02晶粒由柱状晶向等轴晶的演化,从而提高了合金的耐蚀性。
The effect of trace S addition (42-140μg/g) on the corrosion resistance of Zr-4 alloy was investigated in lithiated water with 0.01 mol/L LiOH at 360 ℃/18. 6 MPa by autoclave tests. The mierostructures of the alloys and the oxide films formed on the alloys were observed and analyzed by TEM, EDS and SEM. The results show that the addition of trace S makes the corrosion resistance of ZF4 better, and it becomes more obvious with the increase of S content. The solid content of S in α-Zr matrix was lower than 140μg/g for the alloys in this study. The excess S was precipitated as ZrgFa with tetragonal structure. Trace S addition in Z4 can improve the corrosion resistance in lithiated water with 0.01 mol/I. LiOH at 360 ℃/18.6 MPa by delaying the formation of micro-pores and cracks, as well as the evolution process of ZrO2 columnar grains to equiaxed grains.