(1)Vacuum consumable melting (VAR) process.The rings of the annual ring structure draw the interfaces of different compositions between the solid and liquid phases that exist during the smelting. In the smelting process of titanium alloy ingots, the crystallization speed of the ingot is affected by the fluctuation of the smelting voltage and current. When the smelting current suddenly increases, the temperature in the molten pool rises rapidly, and the crystallization speed decreases, resulting in The solidified solid interface re-melts again, which causes secondary crystallization at the liquid-solid interface. At the same time, the change in crystallization rate also affects the equilibrium distribution process of the total elements at the liquid-phase interface, resulting in A segregation layer similar to the shape of the molten pool is formed on the liquid-solid interface. The more the number of electrical parameter fluctuations, the more segregation layers formed.
(2) is related to deformation. In the two-phase zone at low temperature in multiple fires and small deformations, it is not forged through each time, and the wood is sufficiently crystallized to form an abnormal uneven structure, which is closely related to the forging process parameters and forging heating and holding time.