充氚对不锈钢显微组织及拉伸性能的影响

INFLUENCE OF CHARGING TRITIUM ON THE MICROSTRUCTURES AND TENSILE PROPERTIES OF STAINLESS STEELS HR-1, HR-2 AND 1Cr18Ni9Ti

对 ＨＲ－１， ＨＲ－２， １Ｃｒ１８Ｎｉ９Ｔｉ不锈钢在未充氚、充氚、充氚并除氚 ３种状态下拉伸后的组织进行了透射电镜观察分析；结合力学拉伸性能数据，讨论了氚、氦对这３种不锈钢的组织及拉伸性能的影响观察分析表明，氦易在晶界偏聚；氦偏聚到晶界后形成氦泡，氦泡在晶界处呈现多种组态；氚的最初分布决定了氦的分布，氦通过对氚的捕集强化了氚和氦的聚积；这３种不锈钢充氚后，塑性比未充氚的下降；除氚留氦不锈钢中氦浓度不足以对其塑性产生显著影响。

The effects of internal tritium and helium on the room temperature microstructures and tensile properties of stainless steels HR-1, HR-2 and 1Cr18Ni9Ti were investigated by thermally charging tritium into tensile specimens. Helium bubbles were found mainly in grain boundaries. In some grain boundaries, helium bubbles linked into long chains along the boundaries. Along one direction of the boundaries, the bubbles in each chain extended to smaller and smaller ones till could not been observed. Compared with the results of the same type of stainless steel without internal tritium, the ductilities of all the three tritium-changed stainless steels were degraded. Helium induces fracture or degrades the ductility by trapping tritium in boundaries and altering the distribution of tritium and helium in microstructure. The effects of helium on mechanical properties of the three tritium-changed stainless steels are not obvious.