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Hot extrusion parameters have great influence on the forging property and service life of hub tube. In this paper, the forming process of hub tube with finite element analysis software is simulated to gain the damage values, stress and strain distribution under different processes. And then, hot extrusion parameters, namely, initial forging temperature, squeeze speed and friction coefficients, are optimized through grey relational analysis and variance analysis with the considerations of multiple performance characteristics including injury stress and strain, Experimental results show that the hot extrusion process can be improved effectively through this approach. [ABSTRACT FROM AUTHOR]

A series of related electrophysiology phenomena can be caused by the occurrence of interpolated ventricular premature contraction. In our recent three-dimensional Lorenz R-R scatter plot research, we found that atrioventricular node double path caused by interpolated ventricular premature contraction imprints a specific pattern on three-dimensional Lorenz plots generated from 24-hour Holter recordings. We found two independent subclusters separated from the interpolated premature beat precluster, the interpolated premature beat cluster, and the interpolated premature beat postcluster, respectively. Combined with use of the trajectory tracking function and the leap phenomenon, our results reveal the presence of the atrioventricular node double conduction path.

In this paper, grey-based Taguchi method is firstly used for the optimization of the laser transformation hardening (LTH) process, which is multiple, discrete and uncertain. The grey relational grade acts as the performance characteristic in the Taguchi method, The experimental results has prove the effectiveness of this approach in the optimization of LTH process. [ABSTRACT FROM AUTHOR]

This paper has, for the first time, adopted grey cluster analysis to estimate eight kinds of states of welds in service, including strength, plasticity and toughness such as yield strength, tensile strength, elongation, percentage of section reduction and impact ductility. The cluster league is judged according to the summary of three grey leagues, and the cluster results are fully fitted with the actual status. [ABSTRACT FROM AUTHOR]

In this paper, Narrow Gap Metal Active Gas (NG-MAG) arc welding system was introduced, aiming at efficiently jointing AISI 316LN thick plate used in International Thermonuclear Experimental Reactor (ITER) device. Effect of heat input on cryogenic impact toughness of the WM was investigated and suitable welding parameters were explored to optimize the cryogenic toughness of weld metal (WM) and avoid weld defects simultaneously. Impressively, the maximum low temperature toughness of the NG-MAG arc welded WM could reach more than 100 J, which could be comparable with that of the Tungsten Inert Gas (TIG) arc welded WM. More importantly, the NG-MAG arc welding showed much higher efficiency than the counterpart TIG. The less compositional segregation, and smaller dendrite size due to the lower level of heat input in NG-MAG arc welding were believed to play the critical role in enhancing the cryogenic toughness. [ABSTRACT FROM AUTHOR]