JPH0215801A - Manufacture of titanium alloy channel steel - Google Patents

Abstract

PURPOSE:To roll forming a full-form stock of a Ti alloy by heating and rolling a Ti alloy stock, forming a projected part at a connecting part of a flange and a web parts and a recessed part on the backside of the projected part respectively to form a straight lined half-formed product, and then warm working the half-formed product by forming rolls. CONSTITUTION:A Ti alloy billet is heated and sequentially rolled by rolling rolls to form a half-formed product 2, on which a right angled projected part 6 at a corner part 5 connecting a flange part 3 and a web part 4 and a recessed part 7 whose whose curvature radius is two or more times the sheet thickness of the flange part 3 at the backside of the part 6 are formed, respectively. Then, the product 2 is bitten by a recessed roller 13 and a projecting roller 14 to bend the flange part 3 by an about right angle to the web part 4 in warm working. Succeedingly, a Ti alloy full-form stock 20 having a pair of the flange parts 3 and the web part 4 is manufactured by horizontal rolls 16 and vertical rolls 17.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention utilizes hole-type hot rolling and warm working to produce flat flange parts that are parallel to the flange part and perpendicular to the flange part from a Ti alloy material such as a billet. The present invention relates to a method for manufacturing a Ti alloy channel member having a web portion while suppressing surface flaws.

[Conventional technology] 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.
The I-4V alloy consists of two phases, α+β, at temperatures below about 1000°C, and becomes a single β phase at temperatures above that. Since deformation resistance is lower when processing at high temperatures, β
・It is preferable to perform thermal processing in the phase region, but 1100
When rolling or heating in the β-phase single-phase region at temperatures above ℃, the temperature is too high and coarsening of the β crystal grains occurs. If processing is performed in the α+β region, which causes deterioration, annealing or solution heat treatment and aging treatment will result in equiaxed α+β
Although a good structure can be obtained, processing in the α+β region has a large deformation resistance, and due to the temperature drop during rolling, the α phase precipitates too much, resulting in less elongation.

For these reasons, it has not been conventionally possible to manufacture a shape made of T1 alloy by rolling, and Ti alloy has poor cold formability and is difficult to form 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 Ti alloy shaped material, and it is an object of the present invention to manufacture a groove shaped material of a desired wall thickness made of a Ti alloy by rolling. The purpose is to provide a manufacturing method that allows for

[Means for Solving the Problems] The present inventors have discovered that Ti alloys have poor deformability compared to other materials, have high deformation resistance at high temperatures, and are easily prone to seizure, which are the material factors. The present invention was completed by taking into consideration the forming factors that cause a large difference in the circumferential speed of the rolls at the flange portion during rolling, which tends to cause seizure in the flange portion.

The method for manufacturing a grooved member of the present invention includes rolling a rolled material made of the Ti alloy at
°C and rolled using multiple sets of rolls with predetermined hole shapes, the cross-sectional shape is a straight line between the flange portion and the web portion, and the flange portion and the web portion are connected to each other. Producing a semi-finished product in which a substantially right-angled protrusion is formed at a location corresponding to a corner, and a recess with a radius of curvature at least twice the plate thickness of the flange part is formed on the back side of the protrusion,
Then, the semi-finished product is warm-processed using a forming roll,
The method is characterized by forming a channel material having parallel flange portions and flat web portions.
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 invention uses a plurality of sets of rolls arranged parallel to each other and at least one of which is rotated by a drive device to form a semi-finished product having the above-mentioned cross section from a rolled material such as a billet by groove rolling. In order to reduce the roll peripheral speed difference at the flange portion, the flange portion is made straight like the web portion.

Furthermore, the present invention provides a method for cold rolling a channel steel having parallel flange portions and a perpendicular flat web portion from the semi-finished product. In consideration of the fact that the desired processing amount cannot be obtained in one pass, the number of passes using warm rolls arranged parallel to each other is set at least two passes, and the number of passes is set to be at least two passes, and the process is carried out in a straight line like the web part. The flange part is formed in stages, and the corner part where the flange part and the web part connect is bent to a nearly right angle.Then, in the final finishing process, the web part is bent to prevent the flange part from opening outward. In order to manufacture a channel member in which the flange part is inclined inward by about 1 to 2 degrees with respect to the part, the web part and the flange part are simultaneously formed with a pair of horizontal rolls and a pair of vertical rolls, and there is no need to Appropriate processing prevents partial thickness changes in semi-finished products and prevents scratches from forming on the products.

In addition, the reason why the flange part of the semi-finished product and the web part are made straight in hole hot processing is to reduce the difference in roll circumferential speed at the flange part and prevent seizure from occurring in the flange part. 6 Furthermore, the reason why a nearly right-angled protrusion was formed at a location corresponding to the corner where the flange and web part of the semi-finished product are connected is because molding is difficult in warm forming due to the small protrusion of the meat. Also, the reason for forming a concave part with a radius of curvature more than twice the plate thickness of the flange part on the back side of the protruding part is because if the radius of curvature is less than this, the flange part is processed perpendicularly to the web part during warm rolling. This is because when molding, work hardening occurs locally in the initial stage of molding, making it impossible to obtain good shank angles.

Furthermore, in warm roll processing, pinch rollers are provided before and after the warm roll as necessary. This improves the biting of semi-finished products and prevents slipping of forming rolls.

[Example] The present invention will be explained below based on one embodiment thereof.

The present invention first forms a semi-finished product from a billet using a plurality of sets of rolling rollers having a predetermined groove shape, which are arranged parallel to each other and at least one of which is rotated by a drive device.

1 is a billet, 2 is a pair of flange portions 3 and a web portion 4 that are straight, and has a protrusion 6 that is perpendicular to a portion corresponding to a corner portion 5 where the flange portion 3 and the web portion 4 are connected; This is a semi-finished product in which a recess 7 is formed on the back side of the part 6.

FIG. 1 shows the final rolling rolls for forming the semi-finished product 2, which are arranged parallel to each other and have a predetermined hole shape whose lower part is rotated by a drive device (not shown), and 8 is an upper roll. 9 is a drive roll, and 10 is a hole.

FIG. 2 is a schematic diagram showing a plurality of sets of forming rolls arranged parallel to each other and having a desired roll shape, which are used to warm roll the semi-finished product 2, and 11 is a pinch roller on the entry side; 12 is a pinch roller on the exit side, 13 is a convex roll provided above, and 14 is a concave roll provided below. 3rd rM is a side view showing the roller shapes of a convex roll 13 and a concave roll 14 for processing a semi-finished product.

FIG. 6 shows a pair of horizontal rolls 1 for forming a semi-finished product 2 into a product 20 having a flange portion 3 substantially perpendicular to the web portion 4 and a substantially flat web portion 4 during final finishing.
6 and a pair of vertical rolls.

First, Ti with a cross section of 50 squares and a length of 1000 mm was prepared.
The alloy billet 1 is heated to 1050°C, and then the billet 1 is transferred to a rolling roller by a roller (not shown), and the billet 1 is sequentially processed so that the thickness of the flange portion 3 and the web portion 4 is the same as the product dimensions. The pair of flange portions 3 and the web portion are linear, and a right-angled protrusion portion 6 is formed at a location corresponding to the corner portion 5 where the flange portion 3 and the web portion 4 are connected, and the protrusion portion 6 is formed on the back side of the protrusion portion 6. A first intermediate product 2 was manufactured in which four parts 7 having a radius of curvature of at least twice the thickness of the flange part 3 were formed.

Next, the semi-finished product 2 formed in the first step is transferred to the pinch roller 1.
The flange portion 3 is formed in stages by being held between the concave rollers 13 and 14 convex rollers disposed above and below, and is formed on the web portion 4 without causing any change in thickness or texture. It was bent at a nearly right angle while warm.

Subsequently, in the final finishing process, the semi-finished product 2 is simultaneously formed into the web portion 4 and the flange portion 3 by a pair of horizontal rolls 16 and a pair of vertical rolls 17, so that the pair of flange portions 3 are aligned 1. A T-alloy profile 20 with a flat web section 4 inclined inward at 5° was produced.

[Effects of the Invention] As explained above, the method for manufacturing the Ti alloy H shaped material of the present invention involves hot rolling by heating to a temperature at which an equiaxed α+β structure is obtained. It is possible to impart the necessary ductility to the steel. In addition, the present invention produces a semi-finished product with a straight cross section in the groove hot rolling process, thereby eliminating surface defects even in alloys that have poor deformability and are extremely prone to seizure, such as Ti alloys. A Ti alloy that can be hot-rolled without causing the occurrence of cracks, and has parallel flanges without changing the thickness of the semi-finished product by using a combination of convex rollers and concave rollers even during warm rolling. This enables the production of groove-formed materials at low cost.

In addition, the semi-finished product taken out from hot hole rolling is immediately warm-formed into a straight flange part in a stepwise manner similar to the web part, and the corner part where the flange part and the web part are connected is formed at right angles. It is possible to bend Ti alloy to an angle close to , has low deformation resistance, does not wear out the rollers, prevents work hardening, and can obtain a good apex corner. Channels can be manufactured.

[Brief explanation of the drawing]

Figure 1 is a side view showing the shape of the final rolling roll, Figure 2 is a schematic diagram showing the arrangement of rolls and pinch rollers used in cold rolling, and Figure 3 is a convex roller used in warm rolling. 4 is a side view of the billet, FIG. 5 is a cross-sectional view of the semi-finished product, and FIG. 6 is a side view of the horizontal roll and vertical roll used in the final finishing process. DESCRIPTION OF SYMBOLS 1... Billet, 2... Semi-finished product, 3... Flange part, 4... Web part, 5... Corner part, 6... Protrusion part, 7... Recessed part, 8... ...Top roll, 9...Bottom roll, 10...Hole type, 11 and 12...Pinch roller, 13...Convex roller, 14-ru, - Concave roller, - Vertical roll.・Horizontal entrance Figure 30 2nd Figure 5 Figure 40 60

Claims (1)

[Claims] (1) T formed by a pair of flange parts and a web part
In the production of the i-alloy channel material, the rolled material made of the Ti alloy is heated to 1000 to 1100°C and rolled with multiple sets of rolling rolls with predetermined hole shapes, so that the cross-sectional shape is a pair of The flange portion and the web portion are linear, and a protruding portion that is approximately perpendicular is formed at a location corresponding to the corner portion where the flange portion and the web portion are connected, and furthermore, the radius of curvature is the same as that of the flange portion on the back side of the protruding portion. Manufacturing a semi-finished product with a concave portion twice or more thicker than the plate thickness, and then subjecting the semi-finished product to warm processing using forming rolls to form a channel-shaped member having a parallel flange portion and a flat web portion. A method for producing a characteristic Ti alloy channel member.