Xe~+离子辐照诱导国产T91及316Ti钢微结构变化研究

对国产T91及316Ti钢进行室温下200keV的Xe~+离子辐照,使用X射线衍射(XRD)、透射电镜(TEM)等检测方法研究不同损伤剂量下辐照对材料相的稳定性和微观结构变化的影响。研究结果表明:T91钢辐照后未发生明显相变,而316Ti发生了γ(FCC)→α(BCC)的马氏体相变,且随辐照损伤剂量的增加,α相含量增加,相变的主要驱动力为辐照离子在辐照层的聚集从而产生的剪切应力;T91钢中的M_(23)C_6颗粒随辐照损伤剂量的增加,非晶化越来越明显,主要是由于辐照粒子的轰击削弱了M_(23)C_6颗粒晶格的稳定性,晶格塌陷成为非晶状态;316Ti钢在较低辐照损伤剂量(4.6dpa)下出现黑斑结构,而在高辐照损伤剂量(37.1dpa)下黑斑结构进一步聚集形成位错环。

Microstructure Changes of Domestic T91 and 316Ti Steels Irradiated by Xe+ Ions

Domestic T91 and 316Ti steels were irradiated by 200 keV Xe+ ions at room temperature.The phase stability and microstructure evolution under different irradiation damage doses were investigated with X-ray diffraction (XRD) analysis and transmission electron microscope (TEM).The results show that there is no obvious new phase after irradiation in T91 steel.The martensitic phase transformations from γ (FCC) to α (BCC) are observed in 316Ti steels,and the α phase content increases with the irradiation damage dose.The main contribution to the driving force for the martensitic phase transformations is the plastic deformations induced by the formation of Xe precipitate.M23C6 particles in T91 steel appear amorphous,and become evident with the increase of the irradiation damage dose.The amorphization is attributed to the fact that the Xe+ ions weaken the lattice of M23C6 locally,and the lattice collapses to amorphous state.Black spots are found in 316Ti steels which are irradiated at low doses (below 4.6 dpa),and dislocation loops form from black spots aggregation at high dose (37.1 dpa).