Titanium screws not only undergo strong absorption and reaction with O2, N2, H2, CO, CO2, H2O, and NH3 in the ambient atmosphere during melting, but also interact with the vast majority of known crucible materials. Therefore, the melting of titanium screws needs to be carried out in a protective atmosphere or a blank electric arc furnace, and will be widely used in the future. Due to the use of water-cooled steel volutes in the self consumption furnace, the metal solidification speed is fast and the sequential weaving can be ensured, so the density of the ingot is high. In addition, vacuum melting has a good gas removal effect, which can reduce the metal gas content and improve purity. On the other hand, due to the short melting period and uneven composition of alloys, secondary remelting process is generally used for small-scale production, and in a few cases, even tertiary remelting process is used.

The forging quality of titanium screws is mainly to ensure purity, prevent inclusions and component segregation. Purity mainly refers to the content of elements such as oxygen, nitrogen, and hydrogen in the alloy. In the case of insufficient purity of raw materials, improper electrode preparation and management, and insufficient vacuum during melting, the content of gases such as oxygen and nitrogen increases, and even oxides and nitrides inclusions may appear. When melting titanium screws containing high melting point elements, it is easy to form metal element inclusions, with molybdenum inclusions being the most common, especially for high molybdenum titanium screws. Another metallurgical defect in the manufacturing of titanium screws is compositional segregation. High alumina titanium screws are prone to aluminum segregation, which causes local abnormal changes in phase composition ratios.

The manufacturing defects mentioned above in titanium screws cannot or are difficult to eliminate in the middle of future processing steps, and they have an impact on the forming process and Z-end mechanical properties of titanium screws. Therefore, titanium screw manufacturers strictly control or eliminate them in the melting process.