Failure may occur catastrophically by fracture along grain boundaries when temper embrittlement induced by non-equilibrium grain-boundary segregation (NGS) of phosphorus atoms. Temper embrittlement control technigue b...Failure may occur catastrophically by fracture along grain boundaries when temper embrittlement induced by non-equilibrium grain-boundary segregation (NGS) of phosphorus atoms. Temper embrittlement control technigue based on the theory of NGS and deformation induced phase transformation method was studied in this paper. Grain refinement technique by deformation induced phase transformation in low-alloy steel,12Cr1MoV( which is used in steam pipeline of ships),was experimentally investigated. A single-pass hot rolling process by using a Gleeble-1500 system was performed and the experimental results showed that the grain sizes were obviously affected by the deforming temperature,strain,strain rate and the quenching cooling rate. Temper embrittlement may be controlled and obviously improved by grain refinement.展开更多
Austenitic stainless steels(ASSs)are widely used in various in-dustries such as aerospace,nuclear energy,food,and biotechnol-ogy owing to their exceptional combination of corrosion resistance,weldability,toughness,and...Austenitic stainless steels(ASSs)are widely used in various in-dustries such as aerospace,nuclear energy,food,and biotechnol-ogy owing to their exceptional combination of corrosion resistance,weldability,toughness,and formability[1,2].However,a signifi-cant drawback of ASSs is their low yield strength,which limits their applications in extreme environments[3].Grain boundary(GB)engineering plays a crucial role in enhancing the strength of ASSs[4,5].For instance,grain refinement techniques such as cold rolling followed by annealing[6],severe plastic deformation(SPD)[7],and surface mechanical attrition/rolling treatments[8,9]introduce high-angle GBs(HAGBs)into ASSs,thereby improving their strength.However,the high density of HAGBs limits their ca-pacity for dislocation storage and multiplication,leading to a sig-nificant loss of ductility[10,11].Additionally,several studies have shown that twin boundaries(TBs)can simultaneously enhance the strength,toughness,and corrosion resistance of ASSs[12,13].展开更多
We present a newly developed global magnetohydrodynamic(MHD) model to study the responses of the Earth's magnetosphere to the solar wind. The model is established by using the space-time conservation element and s...We present a newly developed global magnetohydrodynamic(MHD) model to study the responses of the Earth's magnetosphere to the solar wind. The model is established by using the space-time conservation element and solution element(CESE) method in general curvilinear coordinates on a six-component grid system. As a preliminary study, this paper is to present the model's numerical results of the quasi-steady state and the dynamics of the Earth's magnetosphere under steady solar wind flow with due northward interplanetary magnetic field(IMF). The model results are found to be in good agreement with those published by other numerical magnetospheric models.展开更多
文摘Failure may occur catastrophically by fracture along grain boundaries when temper embrittlement induced by non-equilibrium grain-boundary segregation (NGS) of phosphorus atoms. Temper embrittlement control technigue based on the theory of NGS and deformation induced phase transformation method was studied in this paper. Grain refinement technique by deformation induced phase transformation in low-alloy steel,12Cr1MoV( which is used in steam pipeline of ships),was experimentally investigated. A single-pass hot rolling process by using a Gleeble-1500 system was performed and the experimental results showed that the grain sizes were obviously affected by the deforming temperature,strain,strain rate and the quenching cooling rate. Temper embrittlement may be controlled and obviously improved by grain refinement.
基金financially supported by the National Key R&D program(No.2022YFB3707501)the GDAS’Project of Science and Technology(No.2022GDASZH-2022010202)the Guangdong Provincial Project(Nos.2022A0505050053,2021B1515120071,and 2020B1515130007)。
文摘Austenitic stainless steels(ASSs)are widely used in various in-dustries such as aerospace,nuclear energy,food,and biotechnol-ogy owing to their exceptional combination of corrosion resistance,weldability,toughness,and formability[1,2].However,a signifi-cant drawback of ASSs is their low yield strength,which limits their applications in extreme environments[3].Grain boundary(GB)engineering plays a crucial role in enhancing the strength of ASSs[4,5].For instance,grain refinement techniques such as cold rolling followed by annealing[6],severe plastic deformation(SPD)[7],and surface mechanical attrition/rolling treatments[8,9]introduce high-angle GBs(HAGBs)into ASSs,thereby improving their strength.However,the high density of HAGBs limits their ca-pacity for dislocation storage and multiplication,leading to a sig-nificant loss of ductility[10,11].Additionally,several studies have shown that twin boundaries(TBs)can simultaneously enhance the strength,toughness,and corrosion resistance of ASSs[12,13].
基金supported by the National Basic Research Program of China(Grant Nos.2012CB825601,2014CB845903,2012CB825604)the National Natural Science Foundation of China(Grant Nos.41031066,41231068,41274192,41074121,41204127,41174122)+1 种基金the Knowledge Innovation Program of the Chinese Academy of Sciences(Grant No.KZZD-EW-01-4)the Specialized Research Fund for State Key Laboratories
文摘We present a newly developed global magnetohydrodynamic(MHD) model to study the responses of the Earth's magnetosphere to the solar wind. The model is established by using the space-time conservation element and solution element(CESE) method in general curvilinear coordinates on a six-component grid system. As a preliminary study, this paper is to present the model's numerical results of the quasi-steady state and the dynamics of the Earth's magnetosphere under steady solar wind flow with due northward interplanetary magnetic field(IMF). The model results are found to be in good agreement with those published by other numerical magnetospheric models.
