P91 steel is an important bearing material used in nuclear power plants. The study of its mechanical degradation behavior is important for ensuring safe operation. The relationship between the dislocation density of P...P91 steel is an important bearing material used in nuclear power plants. The study of its mechanical degradation behavior is important for ensuring safe operation. The relationship between the dislocation density of P91 steel under different strains and the corresponding nonlinear ultrasonic parameter β was studied. The dislocation density of strained samples was estimated by X-ray diffraction. Nonlinear ultrasonic testing was conducted to evaluate β, showing that this value increased with increasing dislocation density induced by different tensile elongations. It was shown that the ultrasonic secondharmonic generation technique can effectively evaluate the degradation behavior of metallic materials, and the prediction of the residual life of bearing parts in service can be made based on β and the dislocation density.展开更多
文中对 P91 钢两类焊缝的拉伸、冲击、硬度,特别是断裂韧性进行了试验研究。结果表明:强度、硬度高,冲击韧性低的 R 焊缝具有低的断裂韧度,强度、硬度低,冲击韧性高的 D 焊缝具有高的断裂韧度;R 焊缝的低韧性主要与其晶粒粗大、网状晶...文中对 P91 钢两类焊缝的拉伸、冲击、硬度,特别是断裂韧性进行了试验研究。结果表明:强度、硬度高,冲击韧性低的 R 焊缝具有低的断裂韧度,强度、硬度低,冲击韧性高的 D 焊缝具有高的断裂韧度;R 焊缝的低韧性主要与其晶粒粗大、网状晶界及焊接过程中焊接线能量和电流偏大有关,而 D 焊缝的低强度与高的断裂韧度则与焊后二次回火时温度过高有关。对于 R 焊缝,用厚度 12mm 的三点弯曲(SEB)试样测得的条件 KIC(Kq)与厚度 25mm 的紧凑拉伸(CT)试样测得的有效 KIC基本一致。展开更多
基金Item Sponsored by National Natural Science Foundation of China(61171145,11274226)
文摘P91 steel is an important bearing material used in nuclear power plants. The study of its mechanical degradation behavior is important for ensuring safe operation. The relationship between the dislocation density of P91 steel under different strains and the corresponding nonlinear ultrasonic parameter β was studied. The dislocation density of strained samples was estimated by X-ray diffraction. Nonlinear ultrasonic testing was conducted to evaluate β, showing that this value increased with increasing dislocation density induced by different tensile elongations. It was shown that the ultrasonic secondharmonic generation technique can effectively evaluate the degradation behavior of metallic materials, and the prediction of the residual life of bearing parts in service can be made based on β and the dislocation density.
文摘文中对 P91 钢两类焊缝的拉伸、冲击、硬度,特别是断裂韧性进行了试验研究。结果表明:强度、硬度高,冲击韧性低的 R 焊缝具有低的断裂韧度,强度、硬度低,冲击韧性高的 D 焊缝具有高的断裂韧度;R 焊缝的低韧性主要与其晶粒粗大、网状晶界及焊接过程中焊接线能量和电流偏大有关,而 D 焊缝的低强度与高的断裂韧度则与焊后二次回火时温度过高有关。对于 R 焊缝,用厚度 12mm 的三点弯曲(SEB)试样测得的条件 KIC(Kq)与厚度 25mm 的紧凑拉伸(CT)试样测得的有效 KIC基本一致。
