氢蚀对U-2.5Nb合金力学性能的影响

Mechanical Behavior of U-2.5Nb Alloy Attacked by Hydrogen

通过温度和压力变化精确控制U-2.5%Nb合金氢腐蚀的氢消耗量,利用万能拉伸试验机测试不同程度氢腐蚀对U-2.5Nb合金力学性能的影响,用金相和SEM表征该合金氢腐蚀的形貌和断面形貌。结果表明,材料的延伸率和断面收缩率在氢蚀后下降明显,抗拉强度随着腐蚀程度的增加略有下降。根据腐蚀形貌和断面形貌讨论了氢点蚀影响材料力学性能的机制,即氢点蚀引起的蚀坑和微裂纹是造成力学性能下降的主要原因。

To evaluate the effect of hydrogen attack on mechanical properties of U-2.5Nb alloy,hydrogen consumable amount of hydrogen attack was precisely controlled by temperature and gas pressure,and the mechanical properties were measured on a tensile test machine.The morphologies of hydrogen corrosion and fracture surface were observed by SEM and OM.The results show that,ductility parameters such as elongation and reduction decrease distinctly due to hydrogen attack,and ultimate tensile strength decreases slightly with increasing of hydrogen corrosion.According to morphologies of hydrogen corrosion and fracture surface,it is concluded that the micro-cracks and pits induced by hydrogen attack result in the loss of ductility of U-2.5% Nb alloy.