Advanced Materials Research Vols. 472-475

Abstract: The process of dephosphorization for basic electrode and distribution of phosphours between slag and deposited metal(Lp) in manual metal arc welding has been researched by means of experimental and theortical analyses. The results indicate that P content in deposited metal decreased with the increase of coating basicity of the electrode and FeO content in slag. The distributive coefficient of phosphorus Lp increased with the increase of coating basicity of the electrode and FeO content in slag. Although dephosphprylation in deposited metal was a limit finally, it was satisfactory under suitable selsction of the value of FeO in slag and coating basicity of the electrode according to the experimental results.

Abstract: Northern area of Hainan Island is located in the south of Leiqiong faulted zone; new tectonic movement and volcanic activity have intense since late tertiary. Cenozoic volcano in the region is developed, various types of extrusive rocks widely distributed which often directly cumulate on the Cenozoic sedimentary soil layers, then covered by more loose soil, form a soft - hard - soft “sandwich” type slope with a poor stability. Based on the study of this slope and simulate its stability, this paper proposed this kind of slope's destruction mechanism as well as the management method

Abstract: This paper introduced the application of Engineering Critical Assessment (ECA) technology based on fracture mechanics in ocean engineering structures. The application actualities and developing trend of ECA evaluation criterion in domestic and foreign ocean engineering structures were described. The content and process of ECA evaluation at home and abroad were compared, and the key technologies of ECA evaluation in practical projects were summarized.

Abstract: This paper presents a two-step optimization of shape design for the performance improvement of an interior permanent magnet (IPM) motor. Results from the optimized motor demonstrate that the motor performs favorably with respect to minimization of torque ripple and maximization of average torque to PM volume ratio.

Abstract: In this paper, J-integral of inhomogeneous welded joint is calculated by use of the combination of finite element method and virtual crack extension method, and the impact of strength matching on J-integral is studied as well. The analysis results show that the strength matching factor affects J-integral value greatly, that is, low matching of inhomogeneous welded joint of same steel can help to improve the ductility of the welded joint and the influence of the matching performance of dissimilar steel welded joint is more complex.

Abstract: A failure U71Mn rail steel was investigated by stereomicroscopic, scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and laser scanning confocal microscope (LSCM). The results show that, the crack is initiated from heat affected zone (HAZ) of the rail web. The inclusions (Al2O3, SiO2) and the holes in the rail web are the main reasons for the fracture. The deepest of the hole is 64.1μm.

Abstract: The paper by means of a large number of literature was consulted, visit the domestic partial Physical Education College stadiums management departments, realizing the current situation of our country Physical Education College stadiums deeply and the current situation and the existing problems, And the feasibility analysis of industrialization development of stadiums. Finally, the paper puts forward stadium industrialization of management mode and its operating system.

Abstract: The experiments were performed with the twin-wire GMAW machine of Fronius product. The metal transfer process and the arc shapes were observed by use of shadowgraph technique with a high-speed camera. When the arc length increases during twin-wire CO₂ arc welding, the mode of metal transfer changes from short-circuiting transfer to globular transfer, and to spray transfer. But it is difficult to form a stable spray transfer process, and the weld appearance becomes worse. The short-circuiting transfer in twin-wire CO₂ arc welding can improve the process stability.

Abstract: In this study, the Reynolds-Averaged-Navier-Stokes (RANS) model combined with the Cross Viscosity Equation is used, applied to the soft turbulence regime (Ra =5×105~4×107) and hard turbulence regime (Ra>4×107) of Rayleigh-Bénard convection (RBC). The relation curves between heat transport (Nusselt number) and other parameters, as well as flow pattern changes of RBC are obtained for the cases with different Rayleigh number and concentration of the polymer additive. The simulations show that the presence of polymer additive can lead to an enhancement of the heat transfer with larger effect in the hard turbulence regime than those in the soft turbulence regime. It is also shown that in the soft turbulence regime the reversal cycles are shorter than in hard turbulence regime. The symmetric vortices in the diagonal corner of enclosed space shrink and the velocities of large-scale circulation (LSC) increase accordingly.

Abstract: As the fault of the UN5-150ZB rail flash butt welding machine was difficult to be detected and diagnosed, a self-diagnosis system based on communication between PC and PLC was developed to realize fault detection and diagnosis for site operation. The system was implemented by transporting input and output information which including digital and analog, and states of PLC to PC. The computer diagnosis software could judge different fault types automatically on different diagnosis interface. Diagnosis results were printed on screen in text and graph that could provide information of fault types and phase. With the help of diagnosis results, welding productivity can be improved and problems of the equipment can be solved rapidly. Practical application showed that the self-diagnosis system provided a good solution to the fault detection and diagnosis.