Numerical Simulation and Industrial Application of High Speed Tandem TIG Welding

Self-developed high speed tandem TIG welding equipment were adopted to manufacture titanium welded tubes with high efficiency and high quality. The joint made by this high efficient welding process met Chinese standard requirements. A coupled electrode, arc and weld pool numerical model was also developed to investigate temperature and velocity distributions, and energy propagation of this welding process. The numerical results showed that the Marangoni stress was much higher than the arc shear stress, and was mainly positive after leading and trailing arcs in the x and y directions, so the molten metal flowed backward on the top weld pool surface. Previous studies proposed that a “pull-push” flow pattern defined as a backward molten metal flow after the leading arc and a forward molten metal flow before the trailing arc existed on the top weld pool surface in tandem arc welding processes, while it was not observed in this case. The calculated arc efficiency of the high speed tandem TIG welding was about 79.8%.

Feeding and Gating System Design and Simulation of Flange Roller of Hydrators for Yield Melioration

The aim of this paper is showing the advantage of simulation technology in Casting. Casting simulation technique is widely used in foundries and casting industries. Casting simulation simulates the real casting phenomenon and gives a virtual casting process as molten metal flow in mould cavity with respect to time and direction. This paper explains the methods and techniques of feeding & gating system uses to increase the yield of casting in the company. On the basis of the own research it can be stated, that introducing the simulation software bring the great changes in the company, for example: product improvement by prevention of defects, increasing of effectiveness and efficiency in the processes, reduction in timing, proper utilization of material, grater quality, less cost to fulfill defects.

Numerical Modelling of the Molten Metal Flow in a Disk Agitator Mixer

Numerical modelling of the molten metal flow in a crucible under the action of stirred disk agitator is carried out. The influence of the agitator rotational speed on the molten metal flow field is investigated. Dependences of the turbulent diffusivity and the power number on the agitator rotational speed are obtained. The effect of the interaction between the molten metal-air interface and agitator elements on the flow field in a crucible is shown.