The preparation method of TC17 titanium alloy flat square profile includes the following steps: 1. Cutting off the riser and bottom of TC17 titanium alloy ingot, and removing surface defects; 2. The TC17 titanium alloy ingot is opened and forged to obtain the primary forging blank; Third, the primary forging blank is first intermediate forging to obtain the first intermediate forging blank; Fourth, the first intermediate forging blank is carried out the second intermediate forging to obtain the second intermediate forging blank; 5. The second intermediate forging blank is sawed and cut off after forming and forging, and the semi-finished flat square profile is obtained; The semi-finished flat square profile is heat treated to obtain the TC17 titanium alloy flat square profile with a length of 850mm ~ 1600mm, a width of 132mm and a thickness of 65mm ~ 100mm. The invention has the advantages of complete technical scheme, strong process controllability, uniform product structure morphology, excellent comprehensive performance, high batch stability and high yield, and is suitable for large-scale industrial production.
TCl7 titanium alloy is a new type of aero engine material, its nominal composition is Ti-5AL-2Sn-2Zr-4Mo-4Cr. TCl7 titanium alloy has the advantages of high strength, good fracture toughness and high hardenability, and can meet the needs of damage tolerance design and high reliability requirements, and is widely used to manufacture aviation components. With the development of aviation and aerospace industry technology, the demand for TCl7 titanium alloy profiles is increasing. Due to the low phase transition point of the alloy (Tβ is 880℃ ~ 890℃), the conventional preparation method: After heating forging in the temperature range above the phase change point, the method of rolling finished products in the temperature range below the phase change point of 30℃ ~ 50℃ has many problems, such as large deformation resistance, easy cracking of billet, uneven structure, detection clutter is not easy to reach the standard, and the rolled profiles are easy to distort and not easy to straighten, which is not suitable for the mass production of TCl7 titanium alloy flat square profiles. In addition, since TC17 titanium alloy is a typical β-rich two-phase titanium alloy, the β stable elements Mo and Cr content in TC17 titanium alloy is high, and Cr is a eutectoid β stable element, which is easy to form segregation in the head area of the ingot, resulting in Cr enrichment in some areas, which is higher than the normal area of Cr content, so that the phase transition points in these areas are reduced. When the TC17 titanium alloy rectangular profile is in the process of hot working, the actual temperature of the region may exceed the temperature of phase transition point due to the thermal effect of deformation.
