钛合金铸锭尾部冶金质量影响因素研究

The key factors affecting the metallurgical quality of the ingot’s back-end from the perspective of energy input (and heat dissipation) at the start-up stage during vacuum arc remelting (VAR) process were analyzed by the numerical simulation method. The start-up stage process parameters of the third smelting process were studied and verified by experiments. The results show that the surface temperature of the ingot gradually increases with the prolongation of remelting time during the start-up stage, and the surface temperature reaches the highest at the ingot height of 30 mm. By controlling the appropriate time to increase the arc current and accelerate the current rise rate, the surface temperature of the molten pool can be significantly increased. The arc current of TC17 titanium alloy of Φ720 mm increases by 4 kA in the third remelting and rapidly rises to a large current in 1 min, then the holding time of the large current is prolonged by 6 min, which can accelerate the molten pool formation, and the mass of the molten metal is reduced by about half. The numerical simulation and experimental results are in good agreement.