Chemical composition controlling technology for large diameter Ti6A14V ELI ingot

According to the feature of VAR melting, enlarging diameter of titanium ingot will led to increasing the heterogeneity and segregation probability of alloy element. This paper discussed the effect of melting rate and melting current on composition homogeneity for big size Ti6Al4V ELI ingot. Based on the experiences of smaller diameter ingot, VAR melting characteristics, solidification and segregation theories, and combining with industry practice, the optimized melting process was obtained and the very homogeneous Ti6Al4V ELI ingot which size was up to 920mm was also fabricated. The results indicated that the reasonable melting rate and current were two key factors to affecting the distribution alloy element in big sized ingot. The content difference of element of vanadium was only 0.2% from the bottom to up.