JPS63303044A - Manufacture of channel made of ti alloy - Google Patents

Abstract

PURPOSE:To manufacture a channel of desired thickness by means of rolling, by heating a Ti alloy stock to a specific temp., by forming the above into a W-shaped intermediate product by means of hot rolling, and by forming the above into a channel by means of cold forming. CONSTITUTION:A final hot rolls 10 having W-shaped caliber 16 are constituted of the upper roll 12 having two conical projecting parts and the lower roll 14 having, inversely, two conical recessed parts. A Ti alloy stock is heated to 1,000-1,100 deg.C, rolled successively by means of plural couples of rolls for rolling, and then formed into a W-shaped intermediate product 20 consisting of a pair of inclined flanged parts 22a, 22b and a projecting web part 24. Subsequently, the intermediate product 20 is cold-rolled by means of plural stages of rolls 30 for cold forming consisting of the hourglass-shaped upper roll 32 and the drum-shaped lower roll 34 so as to be formed into a channel having parallel flanged parts 22a, 22b and a flat web part 24. By this method, the excellent channel can be manufactured by means of rolling.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for processing a Ti alloy, and more specifically, a groove shaped material made of a Ti alloy is produced by combining hot hole rolling and hot/cold forming. Relating to a method of manufacturing.

[Prior art] Ti alloys, especially α+β type Ti alloys, have a specific strength (tensile strength/
Because it has a high specific gravity) and excellent corrosion resistance, it is used in aircraft materials, space development equipment, etc. However, this α+β type T
Ti alloys, including i-alloys, generally have the disadvantage of high deformation resistance and extremely poor workability, and in addition, they must have a certain structure in order to impart the necessary ductility to the processed product.

That is, Ti-6A is a typical example of α+β type Ti alloy.
For I-4V alloys, α+β at temperatures below about 1000'C
It consists of two phases, and beyond that, it becomes a single β phase. Since the deformation resistance is lower when processing at high temperature, β
It is preferable to carry out hot working in the phase region, but at 1100°C.
In rolling or heating in the above single-phase β-phase region, the temperature is too high and coarsening of the β crystal grains occurs, and even after coarse grain annealing or solution heat treatment, coarse acicular crystals remain and the ductility decreases. If processing is performed in the α+β region, which produces The α phase precipitates too much, resulting in less elongation.

For these reasons, it has not been conventionally possible to manufacture Ti alloy shapes by rolling, and Ti alloys have poor cold formability, making it difficult to form them by bending. Therefore, extrusion molded products were manufactured by extrusion molding, but there were restrictions on the wall thickness of extrusion molded products, and thin walled products could not be manufactured.Therefore, it was hoped that a method of manufacturing Ti alloy shapes by rolling would emerge. It was rare.

[Problems to be Solved by the Invention] The present invention has been made in view of the above-mentioned problems of the shaped material made of the 11 alloy, and it is possible to manufacture a channel shaped material of a desired thickness made of the Ti alloy by rolling. The purpose is to provide a manufacturing method that can.

[Means for Solving the Problems] The method for producing a Ti alloy channel member of the present invention includes a step of heating a rolled material made of a Ti alloy to 1000 to 1100°C, and a step of heating a rolled material made of a Ti alloy to 1000 to 1100°C, and a plurality of sets in which a predetermined hole shape is formed. The rolled material is hot-rolled using rolling rolls, so that the pair of flanges are inclined outward with respect to the perpendicular line, and the web portion is formed into a convex shape, with a W-shaped cross section and a wall thickness of the flange portion and the web portion. forming an intermediate product whose thickness is approximately the same as the product dimensions, and warm or cold forming the convex web portion of the intermediate product to form a groove having a parallel flange portion and a flat web portion. The gist is that it consists of the process of forming materials.

[Function] The rolled material made of Ti alloy is first heated to 1000 to 1100°C.
is heated to. The reason why the heating temperature of the rolled material was set to the above temperature is that if the temperature is 1000°C or less, the deformation resistance is large and rolling is difficult, and at the same time, the elongation of the rolled product after annealing becomes low. This is because if the value exceeds 100%, the ductility decreases due to the residual acicular β phase.

The present inventors discovered that Ti alloy has poor deformability compared to other materials, has high deformation resistance at high temperatures, and is easily prone to seizure, and also that the roll circumferential speed at the flange portion during rolling is Taking into account the forming factors that cause large differences and the tendency for seizure to occur in the flange, hole hot rolling is used to make the wall thickness of the flange and web part the same as the product dimensions, with a W-shaped cross section. The method is characterized in that it is divided into a process of forming an intermediate product, and a process of flattening a convex web portion of the intermediate product using cold forming rolls.

The present invention uses a plurality of sets of rolling rolls arranged parallel to each other and at least one of which is rotated by a drive device to form an intermediate product having a W-shaped cross section from a rolled material such as a billet by groove rolling. In order to reduce the difference in roll circumferential speed at the flange, the flange is inclined outward with respect to the perpendicular line and hot rolled according to the bath schedule shown in FIG.

Furthermore, the present invention provides a method for hot or cold rolling processing of a channel-shaped material having mutually parallel flange portions and a perpendicular flat web portion from an intermediate product having a W-shaped cross section.
Considering that the I alloy has the property of being significantly work hardened by cold working and that the desired processing I cannot be obtained in one pass, the number of passes using warm or cold rolls arranged parallel to each other is at least two. The convex web part is formed step by step to form a flat web part, which prevents partial thickness changes in the intermediate product and scratches on the product due to improper processing. do.

In addition, it is desirable that the inclination angle of the flange part of the intermediate product processed into a W-shape in the groove hot rolling process is 15° to 75°.
This is to reduce the difference in roll circumferential speed at the flange during rolling and to prevent seizure from occurring at the flange, and the reason why the inclination angle is set to 75° or less is because if the flange opens further outward, the web This is because the difference in circumferential speed of the rolls in the web portion becomes large, causing seizure in the web portion.

Furthermore, the radius of curvature of the convex web part formed inside the flange of the intermediate product is preferably at least twice the thickness of the web part; if it is less than this, the web part cannot be flattened during cold rolling. This is because work hardening occurs locally in the initial stage of molding, making it impossible to obtain a good flat part.

In addition, in warm or cold rolling, pinch rollers are provided before and after the warm or cold rolling as necessary. This improves the bite of intermediate products,
This prevents the forming roll from slipping.

[Embodiment] A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a side view of the final hot rolling roll 10. The upper roll 12 has two chevron-shaped protrusions, while the lower roll 1
On the other hand, there are two concave grooves in the shape of a chevron, and a W-shaped hole 16 is formed by the upper and lower rolls. The lower roll 14 is driven by a drive device (not shown).

First, a Ti alloy billet 18 with a cross section of 50 mm and a length of 1000 mm is heated to 1050°C, and then this billet 18 is sequentially rolled using rolling rolls (not shown) according to the bus schedule shown in Figure 2. The final hot rolling roll 10 shown in FIG.

In FIG. 2 (7), the pair of left and right flange portions 22 have approximately the same thickness as the product plate thickness and are inclined outward at 45 degrees with respect to the perpendicular line. A convex web part 24 is formed between one flange part 22a and the other flange part 22b, and the radius of curvature of this convex web part 24 is three times the plate thickness of the web part, and the two The flange portion 22 and the web portion 24 have a W-shaped cross section.

FIG. 3 shows a side view of the cold working roll 30, and FIG. 4 shows a schematic diagram of the arrangement of the cold working roll 30. It consists of a lower roll 34, which is a roller, and bites into the web part 24 of the intermediate product 20, and flattens the web part by combining several stages of rolls. The cold working rolls are arranged in three sets as shown in FIG. 4, with a pinch roll 38 attached to the inlet side and a pinch roll 40 attached to the outlet side.

Intermediate product 2 heat treated using this cold working roll row
0 is held between pinch rolls 38 and bitten by three stages of cold working rolls 30 to form the web portion 24 in stages,
Flange parts 2 that are parallel to each other without any thickness change
50X50X100X with 2 and flat web part 24
Manufactured 3x4000 gutter bars. In addition, when the microscopic structure of the obtained channel material was examined, it was revealed that it was an equiaxed α+β structure and the necessary ductility was obtained.

[Effects of the Invention] As explained above, the method for producing a Ti alloy shaped material of the present invention involves hot rolling by heating to a temperature at which an equiaxed α+β structure is obtained, and the resulting product It is possible to impart the necessary ductility to the steel. Further, by producing an intermediate product having a W-shaped cross section in the hole hot rolling process, even a Ti alloy having high deformation resistance can be easily processed. Furthermore, by gradually deforming and flattening a convexly curved web part during warm or cold rolling processing, a channel member with parallel flanges can be formed, thereby preventing work hardening. Good apex corners can be obtained, and a Ti alloy channel can be manufactured by rolling, which could not be obtained by conventional methods.

[Brief explanation of the drawing]

Figure 1 is a side view of the hot rolling roll, Figure 2 (1) to (7)
) is a side view showing the pass schedule for producing an intermediate product from a billet, Figure 2 (7) is a side view of the intermediate product, and Figure 3 is a side view of the intermediate product.
The figure is a side view of the cold working roll 30, and FIG. 4 is a schematic diagram of the arrangement of the cold working roll 30. 10...Hot rolling roll, 20...Intermediate product, 22
...Flange part, 24...Web part, 30...Cold working roll. ji! jl Figure 2 Z2a 22b Figure 3 Figure 4

Claims (1)

[Claims] (1) Rolled material made of Ti alloy with 1000 to 1100
℃, and the rolled material is hot-rolled using multiple sets of rolling rolls with predetermined hole shapes, so that the pair of flanges are inclined outward with respect to the perpendicular line, and the web portion is shaped into a convex shape. A step of forming an intermediate product having a W-shaped cross section and a wall thickness of the flange portion and the web portion that is almost the same as the product dimensions, and a step of forming the convex web portion of the intermediate product by hot or cold heating. 1. A method for producing a Ti alloy channel, comprising the steps of: forming a channel having parallel flange portions and a flat web portion.