JPH02236261A - Manufacturing method of titanium and titanium alloy wire - Google Patents

Abstract

PURPOSE:To produce a high-quality titanium wire by applying a metallic sheath to the surface of a Ti ingot, carrying out hot and cold workings to finish Ti to the prescribed wire diameter, and then removing the above metallic sheath. CONSTITUTION:An ingot 1 (or a billet) of Ti (or Ti alloy) is inserted into a metallic pipe 2 and caps 3 composed of the same substance as the metallic pipe 2 are attached to both ends, respectively, and welding-all-around is performed to form a clad material 5. At this time, as a material for the metallic pipe 2, a material (carbon steel) capable of maintaining a difference in deformation resistance between the Ti material 1 and itself at <=10kg/mm<2> at the time of hot working is used. Subsequently, this clad material 5 is successively subjected to hot rolling and to cold wiredrawing, annealed, and further subjected to cold wiredrawing to the prescribed wire diameter, and then, the above metallic pipe 2 is removed. By this method, the good-quality Ti wire (or Ti alloy wire) free from surface defects, such as flaw and oxide film, can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a manufacturing method for manufacturing high quality titanium and titanium alloy wires in fewer steps than conventional ones. [Prior Art] Regarding hot working when manufacturing titanium and titanium alloy wire, for example, as shown in "Metallic Titanium and Its Applications JP 26-28" published by Nikkan Kogyo Shimbun, a heating temperature of 70
Rolling is carried out at a finish rolling temperature of 650 to 800°C and a winding temperature of approximately 450°C or higher. After this, as shown in the process diagram in Figure 3, cold working is performed through the steps of stripping → inspection → flaw removal, but this cold working is generally done by annealing by batch processing. A scale is generated, a fluorine-based resin is applied onto it, and after drying, wire is drawn using a dry powder lubricant.

In addition, as a continuous drawing method for titanium wire rods, as shown in Japanese Patent Publication No. 174748/1983, blasting with iron and zinc particles is performed to create an alloy layer on the surface, and then a dry powder lubricant is applied. There is also a method of wire drawing.

[Problem B to be solved by the invention] According to the conventional hot processing described above, since the raw material ingot or billet is exposed and processed,
Surface defects such as a surface oxidation layer, scratches, and rough skin can be avoided. Therefore, the peeling, inspection, and scratch removal steps after hot working shown in FIG. 3 are essential, which leads to an increase in running costs.

In addition, the temperature of exposed raw materials decreases significantly during processing, which increases deformation resistance and increases the load on processing equipment.

Therefore, depending on the wire diameter, extremely large and rigid processing equipment is required, resulting in high equipment costs. Furthermore, during cold working, surface scale and fluororesin coatings have poor lubricity and are prone to seizure. For this reason, the wire drawing speed has to be lowered, resulting in poor productivity. Furthermore, since the lubricating film is easily cut or peeled off, it is necessary to repeat the annealing and film treatment several times, which also increases costs.

Note that if a method is used in which a metal film is formed on the surface of the material wire by blasting or the like, the repetition of annealing and film treatment can be omitted, but in this case, surface roughness etc. occur and the surface condition deteriorates significantly.

An object of the present invention is to provide a method for manufacturing titanium and titanium alloy wire that is effective in solving the above-mentioned problems.

[Means to solve the problem]

In the method of this invention, a metal sheath is applied to the surface of a titanium or titanium alloy ingot or billet, and then this composite material is hot worked and then cold worked to finish the internal titanium or titanium alloy to a predetermined wire diameter. Thereafter, the metal sheath is removed to obtain a titanium or titanium alloy wire.

FIG. 1 shows an example of the metal sheath construction process in this method. In the figure, 1 is an ingot or billet of titanium or titanium alloy, 2 is a metal pipe that covers 1, and 3 is 2
The lids at both ends are made of the same metal as shown in the same figure (al), and then the lid 3 is inserted around the entire circumference as shown in the same figure (b) so that the inside is sealed. When it is welded and attached to 2, the construction of the metal sheath consisting of 2 and 3 is completed.

4 is the welding part. Therefore, the composite material 5 shown in FIG. 1(b) is processed by following the steps after the sheath treatment shown in FIG. 2 to obtain the desired wire rod.

In addition, in this method, if the difference in deformation resistance during hot working between the internal titanium or titanium alloy and the sheath metal is too large, only the metal sheath may deform, or the metal sheath may be too hard and the force that should be transmitted to the inside may be too large. Since the processing force will not be transmitted well to titanium or titanium alloy by unnecessarily killing the material, it is desirable to adjust the difference in deformation resistance between the two during hot processing to 10 kg/mm" or less.

Further, for this adjustment, it is also preferable to use carbon steel as the sheath metal, whose deformation resistance value can be easily changed by adjusting the carbon content.

[Effect]

If titanium or titanium alloy (raw material ingot or pellet) is wrapped in a metal sheath to cut off contact with the atmosphere, surface oxidation of the material will not occur.

Additionally, the metal sheath acts as a heat insulator, keeping the deformation resistance of the raw material during processing low.

Furthermore, since the metal sheath bears the surface load during processing, the load does not cause scratches or roughness on the surface of the raw material. According to the present invention, the above-mentioned effects simplify the process.
Objectives such as downsizing equipment, reducing running costs, and improving product quality are achieved.

Note that the metal sheath can be easily removed by pickling or the like.

[Example 1] JIS standard 1 type industrial pure Ti round billet (100aφ
) was covered with carbon steel having a carbon content of 0.06% so that the sheath cross-sectional area ratio was 20% of the whole. At this time,
A gap of approximately 1 mm was left between the Ti Vilent and the carbon steel sheath. Next, this composite billet is rolled at a rolling heating temperature of 800"C using ordinary steel production equipment; 9.
It was made into a wire rod with a sheath of 5 mmφ. After that, this wire was subjected to 5. dry powder lubricant without annealing. OffIII
After cold drawing to lφ and then annealing at 700°C,
．． The wire was drawn to 12mmφ. Then, when this wire was pickled and the sheath was dissolved, 1. A titanium wire rod of Omφ could be obtained.

Furthermore, the titanium wire was of good quality and had no surface defects such as scratches or oxide films.

(Example 2) Carbon steel with a carbon content of 0.13% was added to a Ti-6%AI-4%■ alloy billet (85 mm) with a sheath cross-sectional area ratio of 20
% to form a composite billet with a gap of about 1 m between the internal Ti alloy billet and the carbon steel sheath. Next, this billet was rolled using normal steel rolling equipment at a rolling temperature of 930"C to a thickness of 9.5 mm.
Made of a wire with a φ sheath. In addition, this wire rod was subjected to 5. The wire was drawn to 0 am+φ, then annealed at 720°C, and further drawn to 1.68 mmφ. Thereafter, the sheath was removed by pickling, and a Ti-6AI-4V titanium alloy wire of 1.5 wφ was obtained, and like Example 1, this wire was also of good quality without surface defects. The carbon steel for the sheath used in each of the above examples has a deformation resistance difference of 10 kg/am'' or less with the internal Ti billet or Ti alloy billet during hot working. For example, peeling after hot processing, inspection,
Defect removal and film treatment during cold working were not performed. The annealing treatment is also performed only once.

(Effects) As described above, according to the present invention, the raw material titanium or titanium alloy ingot or billet is sealed with a metal sheath and hot worked → cold worked, so there is no oxide film, scratches, or rough skin. It is possible to make titanium and titanium alloy wires without such materials.

In addition, the heat retention effect of the metal sheath keeps the deformation resistance of the internal raw material low, so it can be processed even with ordinary steel production equipment that does not have high processing capacity.

In addition, the protective effect of the metal sheath eliminates the need for peeling, inspection, and scratch removal processes, improving yield and productivity.

Furthermore, in cold processing, the metal sheath bears the surface load during processing to prevent scratches and roughness on the surface of the raw material, and to suppress the temperature drop of the raw material after hot processing to keep deformation resistance small. As a result, coating treatment and annealing steps can be largely omitted, and the wire speed can be increased.

Therefore, it becomes possible to provide titanium and titanium alloy wires of higher quality at a lower cost, opening the way for the expansion and popularization of this type of wire.

[Brief explanation of drawings]

Figures 1 (a) and (b) are diagrams showing an example of constructing a metal sheath on an ingot or billet of titanium or titanium alloy, Figure 2 is a process diagram of the method of the present invention, and Figure 3 is a conventional method. This is a process diagram. 1...Titanium or titanium alloy ingot,
2... Metal pipe, 3... Lid, 4
...Welded part, 5...Composite material.
Patent applicant: Sumitomo Electric Industries, Ltd. Agent Fumi Kamata Figure 1

Claims (3)

[Claims] (1) Apply a metal sheath to the surface of a titanium or titanium alloy ingot or billet, then hot work → cold work this composite material to finish the internal titanium or titanium alloy to a predetermined wire diameter, and then, A method for producing titanium and titanium alloy wire, which comprises removing a metal sheath to obtain a titanium or titanium alloy wire. (2) The method for producing titanium and titanium alloy wires according to claim 1, wherein the sheath metal is one whose deformation resistance difference with titanium or titanium alloy is maintained at 10 kg/mm^2 or less during hot working. (3) The method for manufacturing titanium and titanium alloy wires according to claim 2, wherein carbon steel whose deformation resistance during hot working is set to a desired value by adjusting the carbon content is used as the sheath metal.