The heating temperature of TC4 titanium alloy slab is 1000-1050°C in the P phase zone, and the heating temperature of finished product is 950-760°C in the A +P phase zone. The heating temperature is appropriately reduced with the increase of firing times. 3.2mm titanium plate is made of four fire times: a fire from 150mm rolling to 30mm; High initial rolling temperature, many passes, up to 12 passes; Two fire rolling from 30mm to 10mm; Three fire rolling from 10mm to 5mm; Four fire from 5mm to 3.2mm.
(1) breakdown. The ingot is forged or rolled into a titanium slab and the surface is machined. The thickness of titanium slab is 150mm, and the width is mostly 1200mm.
(2) heating. Batch furnace or continuous furnace heating, mostly set below the phase change point, generally 850-870°C, heating time set to ensure full heat absorption.
(3) the rolling. Check the mill before rolling to prevent rolling defects. Pass schedule must be set according to temperature. First rough rolling to a certain thickness, then fine rolling to the final thickness. The thinner sheet should be hot rolled 2-3 times.
(4) hot correction. Immediately after rolling, send the heat rectifying machine for thermal correction. Generally, it should be carried out 1-5 times at high temperature as far as possible. For the thin titanium plate, the effect is not good because of the temperature drop.
(5) heat treatment. Heat treatment with roller bottom furnace or batch trolley furnace, the general annealing temperature is 650-7501.
(6) cut off. The thinner titanium plate is cut off by shearing machine, and the thicker titanium plate is cut off by gas cutting or plasma cutting machine.
A correction (7). According to the shape after heat treatment. Implement as necessary. Thicker plates are cold-pressed for 1500-3000T and thinner plates (for example, up to 20mm) are straightened by cold levelers or by a temperature-leveler at heat treatment temperatures.
(8) alkali washing and pickling treatment. The surface of the pure thick titanium plate is often alkaline and acid cleaning treatment, and the surface quality requirements are strict, but also for grinding.
(9) Inspection and testing. The shape, size and surface of the titanium plate are inspected, and the mechanical properties and metallographic structure are inspected. The strain, roughness, surface hardness, ultrasonic inspection and penetration inspection are often required for the tube plate.