The three-dimensional finite element method of lines is presented, and the basic processing description of 3D FEMOL in cracking questions is given in detail. Applications to 3D bodies with cracks indicate that good ac...The three-dimensional finite element method of lines is presented, and the basic processing description of 3D FEMOL in cracking questions is given in detail. Applications to 3D bodies with cracks indicate that good accuracy can be obtained with relatively coarse girds. In particular, application to the tension specimen shows very good agreement with the evaluation of stress intensity factors, which is better than the results of other methods. This implies a considerable potential for using this method in the 3D analysis of finite geometry solids and suggests a possible extension of this technique to nonlinear material behavior.展开更多
To achieve high carbon hard-facing weld metals with both high hardness andcrack resistance, strong carbide forming elements Ti, Nb and V were alloyed into the weld metals,and their effect on the formation of carbides ...To achieve high carbon hard-facing weld metals with both high hardness andcrack resistance, strong carbide forming elements Ti, Nb and V were alloyed into the weld metals,and their effect on the formation of carbides and the matrix microstructure were studied. ElectronProbe Microanalysis (EPMA), Energy Dispersive Spectroscopy(EDS) and Transmission ElectronMicros-copy(TEM) were adopted to investigate the microstructure, then thermodynamics of theformation of carbides was calculated and their effect on the matrix was further discussed. It isrevealed that Nb, Ti and V influence strongly the distribution and existing state of carbon,inducing precipitation of carbides accompanying with the depletion of carbon in matrix. But whenonly V are alloyed as carbide forming element, the carbides are scarce and distributed along grainboundaries, and the hard-facing alloy is too hard, while the using of only Nb or Ti could notreinforce the weld metals effectively. The hard-facing alloy reinforced with Nb, V and Ti can formdispersive fine carbides and low carbon martensite matrix.展开更多
文摘The three-dimensional finite element method of lines is presented, and the basic processing description of 3D FEMOL in cracking questions is given in detail. Applications to 3D bodies with cracks indicate that good accuracy can be obtained with relatively coarse girds. In particular, application to the tension specimen shows very good agreement with the evaluation of stress intensity factors, which is better than the results of other methods. This implies a considerable potential for using this method in the 3D analysis of finite geometry solids and suggests a possible extension of this technique to nonlinear material behavior.
基金This work was financially supported by Nature Science Foundation of Shandong Province (No.Y99F01).
文摘To achieve high carbon hard-facing weld metals with both high hardness andcrack resistance, strong carbide forming elements Ti, Nb and V were alloyed into the weld metals,and their effect on the formation of carbides and the matrix microstructure were studied. ElectronProbe Microanalysis (EPMA), Energy Dispersive Spectroscopy(EDS) and Transmission ElectronMicros-copy(TEM) were adopted to investigate the microstructure, then thermodynamics of theformation of carbides was calculated and their effect on the matrix was further discussed. It isrevealed that Nb, Ti and V influence strongly the distribution and existing state of carbon,inducing precipitation of carbides accompanying with the depletion of carbon in matrix. But whenonly V are alloyed as carbide forming element, the carbides are scarce and distributed along grainboundaries, and the hard-facing alloy is too hard, while the using of only Nb or Ti could notreinforce the weld metals effectively. The hard-facing alloy reinforced with Nb, V and Ti can formdispersive fine carbides and low carbon martensite matrix.
