中文摘要：

液态金属与结构材料间的润湿程度是影响液态金属脆化（LME）效应的关键因素。为探索T91钢在液态铅基合金中的脆化机制，采用静滴润湿性测量实验和界面微观分析方法研究了Pb／PbBi合金在光滑T91钢表面的接触角和界面元素分布规律。测量结果表明，在相同测试温度下，PbBi—T91体系间的接触角稍大于Pb—T91间的接触角，且均大于90°。当温度低于400℃时，两个体系的接触角随温度的升高均有下降的趋势，而当温度高于400℃时，接触角则基本保持不变。微观分析结果显示，两个体系的界面均未发生明显的反应，PbBi合金中Bi原子的表面偏聚引起气一液界面张力降低，这可能是导致PbBi—T91间的接触角大于Pb-T91间接触角的原因。

英文摘要：

Wetting of structure material with liquid metal is one of the key influence factors on liquid metal embrittlement （LME） effect. In order to investigate LME mechanism for T91 in liquid Pb alloys, contact angles and interface interaction of molten Pb/ PbBi alloy on T91 were studied with sessile drop （SD） method and microscopic examination. The results indicate that the contact angle of T91 with molten PbBi is larger than that with Pb at the same temperature, and all the contact angles are larger than 90°. Moreover, the contact angles decrease with the increase of the temperature when the temperature is under 400 ℃, but they remain constant when the temperature is higher than 400℃. SEM examination shows that there is no obvious reactivity on the interface of both systems. The decrease of interface tension between liquid PbBi alloy and gas is caused by the surface segregation of Bi atoms, which might lead to the contact angle of T91 with PbBi is larger than that with molten Pb.