CN104372203A - Novel alpha titanium alloy and preparation method of panel and bar of alpha titanium alloy - Google Patents

Abstract

The invention relates to a novel alpha titanium alloy, and belongs to the technical field of an alloy preparation process. The alpha titanium alloy comprises the following components by mass percent: 5.0-7.0wt% of aluminum, 4.0-5.0wt% of chromium, 1.0-2.0wt% of manganese, not more than 0.1wt% of total of oxygen, carbon, nitrogen and hydrogen, and the rest of iron. By using alloying element Cr and Mn with low cost as reinforcing elements of the alpha titanium alloy, the traditional alloy elements with high price such as Sn, Mo, Zr and V are substituted; the result shows that the new alloy has good comprehensive performance. Through the adoption of the titanium alloy disclosed by the invention, the selective range of the alloying elements of the alpha titanium alloy is broadened, and a certain innovation and theoretical property guidance are provided for the further development of the alpha titanium alloy.

Description

A kind of preparation method of novel α-titanium alloy and plate and bar thereof

technical field

The invention relates to a novel α-titanium alloy and a preparation method thereof, and belongs to the technical field of titanium alloy material preparation technology.

Background technique

Titanium alloy has a series of excellent comprehensive properties such as low density, high specific strength, high temperature resistance, corrosion resistance and good biocompatibility, so it is widely used in various industrial fields, and is called "space metal" and "ocean metal". , "smart metal" and so on. In addition, since the industrialization of sponge titanium, the production capacity of titanium has been increasing year by year, and titanium is widely distributed in nature. The content of titanium in the earth's crust is 0.64%, ranking ninth among all elements and second only to metal elements. In terms of aluminum, iron and magnesium, it ranks fourth, which is more than the sum of common copper, lead and zinc metal reserves. As of 2009, the world's proven titanium resources (calculated as TiO ₂ ) totaled 2.484 billion tons, and the economic reserves with economic mining value were 1.382 billion tons. It can be said that the resources are abundant, so the development and utilization of titanium alloys has a very broad prospect. .

After long-term practice, the damage tolerance design that takes both strength and toughness into consideration has become a concern in the application of titanium and titanium alloy materials. The preparation of titanium alloy materials with higher strength and better toughness is the goal that is constantly pursued. Alloying is the most fundamental means among many technical means to improve and enhance the strength and toughness of titanium alloys. According to the microstructure characteristics after annealing, titanium alloys can be divided into three categories: α, (α+β) and β-type titanium alloys. Among them, α-type titanium alloys are single-phase alloys composed of α-phase solid solutions. Under high practical application temperature, the matrix phase is all α phase, the structure is stable, α titanium alloy has low density, good thermal strength, thermal stability and excellent room temperature, ultra-low temperature and high temperature characteristics, so the research and development of α titanium alloy It has always been the focus of attention from all over the world.

After long-term practice, the damage tolerance design that takes strength and toughness into account has become a concern in the application of titanium and titanium alloy materials. It is a constant pursuit to prepare titanium alloy materials with higher strength and better toughness. Alloying is the most fundamental means among many technical means to improve and enhance the toughness of titanium alloys, and it is also an important method to develop new titanium alloys. However, the selection of alloying elements for α-titanium alloys has been limited to a few elements, such as Sn, Mo, Zr, V, etc., and there are few attempts for new alloying elements such as Cr and Mn. It is a problem that needs to be solved in the development of new α-titanium alloys to determine the types of alloying elements and to study their influence on the microstructure and properties of titanium alloys.

Contents of the invention

Aiming at the problems existing in the research and development of new α-titanium alloys, the object of the present invention is to provide a new α-titanium alloy, which is a new type of α-titanium alloy containing Cr and Mn alloy elements. A novel α-titanium alloy of the present invention is characterized in that it has the following components and mass percentages: 5.0-7.0 wt% aluminum, 4.0-5.0 wt% chromium, 1.0-2.0 wt% manganese, other oxygen, carbon, The total amount of nitrogen and hydrogen ≤ 0.1 wt%, and the balance is titanium;

A kind of preparation method of novel α-titanium alloy profile of the present invention is characterized in that having following preparation process:

a. Plate preparation

CCIM method (i.e. vacuum induction suspension melting method): pure titanium, pure aluminum, pure chromium, pure manganese are pretreated in a box-type resistance furnace after batching, that is, kept at 180°C for 12 hours, and then placed in a water-cooled copper crucible , wash the furnace repeatedly for 4 times, backflush 0.006 MPa argon as a protective gas, and repeatedly melt for 4 times in the temperature range of 10-150 °C higher than its melting point to obtain an oval ingot, which is heated to 760 °C, in Hot rolling on the horizontal rolling mill, after 5 passes, the deformation rate of each pass does not exceed 15%, and a plate with a thickness of 6~7mm is obtained; then the plate is subjected to vacuum annealing heat treatment, the annealing temperature is 700 ° C, the holding time 2h, the cooling method is air cooling;

b. Bar preparation

VAR method (that is, vacuum induction consumable melting method): pure titanium, pure aluminum, pure chromium, titanium-manganese intermediate alloys are pressed into electrode blocks by extrusion method after batching, and then welded by arc welding in a vacuum-argon filled box. The electrode blocks are welded together as a vacuum consumable electrode. After power-on, the arc discharge between the consumable electrode and the molten pool generates high temperature to melt the electrode to obtain metal titanium ingots. The titanium ingots are heated to 1050°C for 2 to 3 times, and the Repeated upsetting and elongation of the forged billet for 2~3 fires to obtain a rolled billet of φ20mm, the surface cracks are cleaned, and air cooled to room temperature to obtain the finished bar; then the bar is subjected to vacuum annealing heat treatment, the annealing temperature The temperature is 700°C, the holding time is 2h, and the cooling method is air cooling.

Detailed ways

The present invention will be further described below by specific examples.

Example 1

Pure titanium, pure aluminum, pure chromium, and pure manganese are mixed according to the composition ratio in Table 1, pretreated in an ordinary box-type resistance furnace (180°C for 12 hours), and free water in the alloy raw materials is removed. Then place it in a water-cooled copper crucible, wash the furnace repeatedly for 4 times, then recoil 0.006 MPa of argon as a protective gas, and repeatedly smelt it for 4 times to obtain an oval ingot. Rolling, after 5 passes of rolling, the deformation rate of one pass does not exceed 15%, and a plate with a thickness of 6~7mm is obtained. After the rolled plate is heat-treated according to the heat treatment system in Table 2, samples are taken and tested for mechanical properties at room temperature according to the requirements of the national standard GB/T228-2002. The mechanical properties are shown in Table 2.

the

The composition ratio of the alloy in Table 1 Example 1

chemical element Al Cr mn o N C h Ti Content (wt%) 6.36 4.77 1.64 0.05 0.001 0.001 0.001 margin

Table 2 The mechanical properties of the plate in Example 1

Heat treatment system Tensile strength Rm (MPa) Yield strength Rp0.2 (MPa) Elongation after breaking A (%) Reduction of area Z (%) Elastic modulus E(GPa) 700℃/2h/AC 1060.0 1039.0 8.4 37.0 95.0

Example 2

Mix pure titanium, pure aluminum, pure chromium, and titanium-manganese intermediate alloys according to the composition ratio in Table 3. After the ingredients are mixed, they are pressed into electrode blocks by extrusion method, and then the electrode blocks are welded by arc welding in a vacuum-argon-filled box. Weld together as a vacuum consumable electrode. After power on, the arc discharge between the consumable electrode and the molten pool generates high temperature to melt the electrode to obtain metal titanium ingots. The titanium ingots are heated to 1050°C and forged for 2 to 3 times. Repeated upsetting and elongation forging for 2~3 times to obtain a φ20mm billet, polished the surface cracks, and air cooled to room temperature to obtain a finished bar. After the obtained bar was heat treated according to the heat treatment system in Table 4, samples were taken and tested for mechanical properties at room temperature in accordance with the requirements of the national standard GB/T228-2002. The mechanical properties are shown in Table 4.

The composition ratio of the alloy in Table 3 Example 2

chemical element Al Cr mn o N C h Ti Content (wt%) 6.36 4.79 1.65 0.05 0.001 0.001 0.001 margin

The mechanical property of bar in the table 4 embodiment 2

Heat treatment system Tensile strength Rm (MPa) Yield strength Rp0.2 (MPa) Elongation after breaking A (%) Reduction of area Z (%) Elastic modulus E(GPa) 700℃/2h/AC 1068.0 1043.0 8.2 35.0 93.0

Claims (2)

1. A novel α-titanium alloy, characterized in that: the composition of the novel α-titanium alloy is 5.0-7.0 wt% aluminum, 4.0-5.0 wt% chromium, 1.0-2.0 wt% manganese, other oxygen, carbon, nitrogen , The total amount of hydrogen is ≤0.1 wt%, and the balance is titanium. 2. A preparation method of a novel α-titanium alloy profile is characterized in that it has the following preparation process: a. Plate preparation CCIM method (i.e. vacuum induction suspension melting method): Pure titanium, pure aluminum, pure chromium and pure manganese are prepared according to the above formula and pretreated in a box-type resistance furnace, that is, kept at 180°C for 12 hours, and then placed in water cooling In the copper crucible, wash the furnace repeatedly for 4 times, backflush 0.006 MPa of argon as a protective gas, and repeatedly smelt 4 times in the range of 10-150 °C higher than its melting point to obtain an oval ingot, and heat the obtained ingot to 760 ℃, hot rolling on a tandem rolling mill, after 5 passes, the deformation rate of one pass does not exceed 15%, and a plate with a thickness of 6~7mm is obtained; then the plate is subjected to vacuum annealing heat treatment, and the annealing temperature is 700°C , the holding time is 2h, and the cooling method is air cooling; b. Bar preparation VAR method (i.e. vacuum induction consumable smelting method): Pure titanium, pure aluminum, pure chromium, titanium-manganese intermediate alloys are pressed into electrode blocks by extrusion method according to the above formula, and then used in a vacuum-argon filled box. Arc welding welds the electrode blocks together to obtain a vacuum consumable electrode of the required size. After the power is turned on, the arc discharge between the consumable electrode and the molten pool generates high temperature to melt the electrode and obtain a metal titanium ingot. The titanium ingot is heated to 1050°C to open the billet Forging 2~3 times, repeatedly upsetting and elongating the forging billet for 2~3 fires to obtain a φ20mm rolled billet, polishing the surface cracks, and air cooling to room temperature to obtain a finished bar; then the bar is again For vacuum annealing heat treatment, the annealing temperature is 700°C, the holding time is 2h, and the cooling method is air cooling.