Heat Treatment Process Of Β21s Titanium Alloy Plate

It has been found that Β21s titanium alloy not only has excellent oxidation resistance, but also the corrosion resistance of this alloy is improved by one to two orders of magnitude compared with ordinary titanium alloy. The alloy has good room temperature plasticity in the solid solution state, so it has good hot and cold working properties and can be used to process aerospace sheet metal products. The main β-stabilizing elements of the alloy are high melting point molybdenum and rhenium, which makes the alloy has good oxidation resistance, and can be used to manufacture parts for long-term use in high temperature environments up to 500℃. At present, the United States has used β21s titanium alloy plate to manufacture Boeing 777 aircraft engine nacelle parts as well as high-temperature parts of the space shuttle and titanium composite materials. However, the solid solution treatment system for plate forming and the aging system used for parts have not been reported.

In view of this, the researchers studied the effects of different solid solution temperatures on the microstructure and room temperature mechanical properties of β21s titanium alloy plates, and selected different aging temperatures to study the effects of aging temperatures on the room temperature and high temperature mechanical properties of β21s titanium alloy plates. β21s titanium alloy sheet.

Primary titanium sponge, aluminum beans, aluminum germanium intermediate alloy, titanium molybdenum intermediate alloy and other raw materials are homogeneously mixed and pressed and welded into self-consumption electrodes, and three times melting on a 1000kg vacuum self-consumption electric arc furnace to produce β21s. Finished ingots of titanium alloys, and the ingots' chemical compositions are in accordance with the requirements of the U.S. ASTM B265 standard. The ingots are heated in the β-phase region and then forged in the (α+β) phase region to form slabs with dimensions of 60mm x 400mm x 600mm. The slab is then hot rolled in the (α+β) phase zone to a thickness of 6 mm. Finally, the slabs were cold rolled to 2 mm thickness and tested after pickling and cleaning the surface. Four solid solution temperatures (800, 815, 830, and 845°C × 10 min, air cooling) and three aging temperatures (550, 600, and 680°C × 8h, air cooling) were selected to study the solid solution temperature and aging. The effect of temperature on microstructure and mechanical properties of β21s titanium alloy plate. The test results are as follows:

(1) β21s titanium alloy plate in high temperature solid solution, with the increase of solid solution temperature, solid solution strength decreases and plasticity increases.

(2) The solid solution and aging mechanical properties of β21s titanium alloy sheet have a great relationship with the selection of aging temperature. As the aging temperature increases, the aging strength of the alloy decreases and the plasticity increases.

(3)β21s titanium alloy sheet can obtain the required room temperature processing plasticity after solid solution at 845℃. After aging at 600°C, the room temperature tensile strength can reach more than 1200MPa, and the elongation can be maintained at more than 10%. Meanwhile, its 500℃ high temperature tensile strength can reach over 700MPa.