High-toughness titanium alloy and method for preparing bar by using titanium alloy

Abstract

The invention discloses a high-toughness titanium alloy. The high-toughness titanium alloy comprises the following chemical components of, in percentage by mass, 4.0%-6.0% of Al, 1.0%-3.0% of Mo, 1.0%-3.0% of Zr, 0.5%-1.0% of Fe, 0.2%-0.5% of V and the balance Ti and inevitable impurities. The method for preparing the bar by using the high-toughness titanium alloy comprises the following steps that aluminum titanium, molybdenum titanium, iron nails, titanium-vanadium intermediate alloy, pure zirconium sponge and titanium sponge are correspondingly weighed, mixed and pressed into an electrode bar, and the electrode bar is smelted in a vacuum consumable electro-arc furnace for two times to obtain a titanium alloy cast ingot; the surface of the titanium alloy cast ingot is coated with a puretitanium plate with the thickness of 1.0-2.0 mm, an anti-oxidation coating is brushed on the surface of the pure titanium plate, and the titanium alloy cast ingot is aired for later use; the titaniumalloy cast ingot is placed in a heating furnace to be heated to 930-1150 DEG C, and heat preservation is conducted; and the ingot heated by a radial forging machine is forged to obtain a forging blank; and the forging blank is straightened by using a press machine by using waste heat, and finally machining is conducted to obtain the bar. According to the high-toughness titanium alloy and the method for preparing the bar by using the titanium alloy, the bar prepared from the titanium alloy is high in strength, high in plasticity, high in low-temperature impact toughness and good in corrosion resistance, and the application requirements of severe working conditions of oil and gas wells are met.

Description

technical field [0001] The invention relates to the field of manufacturing titanium alloys and rods, in particular to a high-toughness titanium alloy and a method for preparing rods using the titanium alloy. Background technique [0002] As global energy exploitation becomes more and more extensive, there are not many oil and gas wells with good well conditions and small depths. More and more oil and gas wells are concentrated in areas with harsh underground environments, such as the Sichuan Basin, the main production area in my country at present. , the oil and gas wells in this area contain more H2S and CO2, the well conditions are relatively bad, and the depth reaches more than 6000 meters. In order to solve the problem of high-sulfur oil and gas energy exploitation, many companies at home and abroad choose TC4 to make oil and gas well pipes for oil and gas development. The reason is that when titanium alloy is used for oil and gas exploitation, it has excellent corrosion ...

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Problems solved by technology

However, it has been found in practice that due to various effects such as pulling, twisting, etc. in the downhole, the oil well pipe is subjected to internal pressure of tens of MPa, and the stress situation is complicated. The alloy has insufficient impact performance and stress corrosion resistance. Unable to meet the material performance requirements of high-pressure oil and gas extraction

Later, some companies also used TC21, TC23 and other alloys to prepare oil well pipes. These alloys are based on TC4 (Ti-6Al-4V) alloys, adding rare and precious elements such as Pt and Ru, although their impact properties and stress corrosion resistance are limited. increased, but the cost of materials has also increased a lot

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