The effects of plastic deformation and H2 S on fracture toughness of high strength casing steel（C110 steel） were investigated. The studied casing specimens are as follows： original casing, plastic deformation（PD）...The effects of plastic deformation and H2 S on fracture toughness of high strength casing steel（C110 steel） were investigated. The studied casing specimens are as follows： original casing, plastic deformation（PD） casing and PD casing after being immersed in NACE A solution saturated with H2S（PD＋H2S）. Instrumented impact method was employed to evaluate the impact behaviors of the specimens, meanwhile, dynamic fracture toughness（JId） was calculated by using Rice model and Schindler model. The experimental results show that dynamic fracture toughness of the casing decreases after plastic deformation. Compared with that of the original casing and PD casing, the dynamic fracture toughness decreases further when the PD casing immersed in H2 S, moreover, there are ridge-shaped feature and many secondary cracks present on the fracture surface of the specimens. Impact fracture mechanism of the casing is proposed as follows： the plastic deformation results in the increase of defect density of materials where the atomic hydrogen can accumulate in reversible or irreversible traps and even recombine to form molecular hydrogen, subsequently, the casing material toughness decreases greatly.展开更多
ASME Code Case 2843(以下简称为“案例”)提供了针对高温工况和交变载荷下承受蠕变和疲劳损伤交互作用的受压元件进行评定的方法。在应用该案例方法的过程中,如不能理解这些方法的技术基础,则可能造成评定结果的不安全。案例中所提出...ASME Code Case 2843(以下简称为“案例”)提供了针对高温工况和交变载荷下承受蠕变和疲劳损伤交互作用的受压元件进行评定的方法。在应用该案例方法的过程中,如不能理解这些方法的技术基础,则可能造成评定结果的不安全。案例中所提出的蠕变-疲劳损伤评定方法主要利用线弹性分析得到的结果对弹塑性材料构成的受压元件进行评定。整套方法包括载荷控制极限的判定、应变控制极限的判定以及蠕变-疲劳损伤极限的判定三个步骤,每个步骤中采用的方法均依据多年来有关研究人员发表文献中的理论和实验结果。拟对案例中所采用方法的技术基础进行分析,为工程中应用案例的方法对承受高温和交变载荷作用的压力容器进行设计提供一定的参考。展开更多
基金Funded by the Construction of Key Disciplines for Young Teacher Science Foundation of the Southwest Petroleum University(No.P209)the Research Fund for the Doctoral Program of Higher Education(No.20105121120002)the National Natural Science Foundation of China(Nos.51004084 and 51374177)
文摘The effects of plastic deformation and H2 S on fracture toughness of high strength casing steel（C110 steel） were investigated. The studied casing specimens are as follows： original casing, plastic deformation（PD） casing and PD casing after being immersed in NACE A solution saturated with H2S（PD＋H2S）. Instrumented impact method was employed to evaluate the impact behaviors of the specimens, meanwhile, dynamic fracture toughness（JId） was calculated by using Rice model and Schindler model. The experimental results show that dynamic fracture toughness of the casing decreases after plastic deformation. Compared with that of the original casing and PD casing, the dynamic fracture toughness decreases further when the PD casing immersed in H2 S, moreover, there are ridge-shaped feature and many secondary cracks present on the fracture surface of the specimens. Impact fracture mechanism of the casing is proposed as follows： the plastic deformation results in the increase of defect density of materials where the atomic hydrogen can accumulate in reversible or irreversible traps and even recombine to form molecular hydrogen, subsequently, the casing material toughness decreases greatly.
文摘ASME Code Case 2843(以下简称为“案例”)提供了针对高温工况和交变载荷下承受蠕变和疲劳损伤交互作用的受压元件进行评定的方法。在应用该案例方法的过程中,如不能理解这些方法的技术基础,则可能造成评定结果的不安全。案例中所提出的蠕变-疲劳损伤评定方法主要利用线弹性分析得到的结果对弹塑性材料构成的受压元件进行评定。整套方法包括载荷控制极限的判定、应变控制极限的判定以及蠕变-疲劳损伤极限的判定三个步骤,每个步骤中采用的方法均依据多年来有关研究人员发表文献中的理论和实验结果。拟对案例中所采用方法的技术基础进行分析,为工程中应用案例的方法对承受高温和交变载荷作用的压力容器进行设计提供一定的参考。
