JPH01162503A - Method for lamination rolling of titanium or titanium alloy - Google Patents

Abstract

PURPOSE:To perform lamination rolling without peeling during rolling and to obtain a clad stock easily peelable after rolling by interposing a peeling sheet made of a specific thick paper or an organic compound film between facing titanium slabs. CONSTITUTION:As for clad rolling of base stocks 1 (stainless steel slab, etc.) with titanium or titanium alloy slabs 2, a peeling agent 3 is interposed between the titanium slabs 2, interpolation plates 4 are installed in both sides of the peeling agent 3. A <=0.2mm thick sheet of paper or an organic compound film consisting of C, H, O, and N elements (polyethylene, etc.) are used as the sheet 3. Hence, lamination rolling without fear of peeling during rolling and easy peeling after rolling are performable.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for manufacturing a titanium thin plate or a titanium clad plate, and more specifically, in hot rolling of a titanium thin plate or a titanium clad plate, it is necessary to thin the titanium thin plate or titanium clad plate. For this purpose, or to cover the asymmetry of deformability and deformation resistance in the thickness direction, laminated rolling is performed, and after rolling, it is peeled off to form a thin plate.

The present invention provides a method for laminated rolling of titanium in which peeling does not occur during rolling and peeling after rolling is easy.

(Prior Art) Titanium sheets are usually produced by hot rolling and cold rolling. In hot rolling, it depends on the performance of the rolling mill, but at most 2 m.
The maximum thickness is about m, and to roll to a thickness smaller than that, cold rolling is performed. Cold rolling has a fine surface finish, but
Large mill power is required and manufacturing cost is also high. On the other hand, hot rolling requires heating costs and the rolling surface has a rougher finish than cold rolling, but it is cost-effective especially when rolling in large quantities because a relatively small mill power is sufficient. It is. A hot-rolled surface may be sufficient for the surface finish, but stack rolling has traditionally been used when thinning is required.

(Problems to be Solved by the Invention) Although stack rolling is excellent in terms of thinning, it has a major drawback in that interfaces bond and it is difficult to separate them after rolling. Particularly in the case of titanium and titanium alloys, this bond was particularly strong, making peeling extremely difficult.

On the other hand, stack rolling is sometimes performed with titanium surfaces butted against each other in order to avoid warping stress caused by asymmetric rolling in single-sided titanium clad steel sheets. (“Titanium/Zirconium J Vol, 35 No. 1 2391
(published in 1987). In this case as well, it was strongly bonded on the titanium surface and it was very difficult to separate it.

Conventionally, in order to prevent such adhesive bonding at the interface, ceramic powder was applied to the interface and the interface was oxidized. As ceramic powders, for example, fusix containing AIZO, CaO, etc., and antioxidants have been used. Preventing adhesion by these ceramic powders is certainly effective as long as they remain at the interface, but of course the risk of peeling during rolling increases significantly. Therefore, these methods require contradictory properties such as aiming at adhesion prevention while bonding, and as a result, both properties are unsatisfactory. Because of the lack of a suitable release agent, laminated rolling, which is advantageous for producing ultra-thin materials, has not been widely used.

The present invention solves the above-mentioned problems and provides a laminated rolling method that satisfies industrially the requirements of bonding without peeling and facilitating peeling.

(Means for Solving the Problems) The present invention provides a method for manufacturing plate materials in which titanium or titanium alloy slabs are laminated, hot rolled, and then peeled off, with a thickness of 0.2 mm or less at the laminated interface. Paper or C, H, O, N
This is a method for laminated rolling of titanium and titanium alloys, characterized in that hot rolling is carried out with an organic compound film consisting of:

The present inventors have focused on the fact that the contradictory required properties of facilitating bonding and facilitating peeling are required at different times. That is, the time when bonding is required is during hot rolling, and the time when peeling is required to be easy is after hot rolling and cooling. If they are not bonded during hot rolling, they will peel off into two pieces, making it impossible to perform laminated rolling and not be able to take advantage of its advantages. The laminated rolled material is peeled off after hot rolling, but in this case the temperature is lower than that during rolling. Of course, it is possible to peel off the film by heating it to a high temperature, but considering the cost of heating, it is much more advantageous to peel it off at a low temperature, even at room temperature.

Based on the above idea, we searched for materials that have excellent bonding properties at high temperatures and excellent peeling properties at low temperatures, and as a result, we found that carbide nitrides and oxides meet these requirements. In other words, titanium carbides, nitrides, and oxides maintain a relatively good bond at high temperatures because they partially form a solid solution, but at room temperatures they precipitate in large amounts and behave similarly to inclusions, causing their surfaces to become brittle. I will do it. Therefore, although there is no fatal peeling factor at the interface between titanium, titanium alloys, or iron at high temperatures, cluster-like carbide nitoxides form at low temperatures.
By sandwiching, it is possible to simultaneously satisfy the contradictory required characteristics of bonding and facilitating peeling.

Next, the limiting conditions of the present invention will be explained.

Carbon sandwiched between laminated interfaces of titanium or titanium alloys.

The nitrogen and oxygen sources are limited to paper or organic compound films made of C, H, O, and N, since there is no problem as long as they are film-like materials that do not contain particularly harmful elements other than C, N, and O. Since hydrogen is dissolved in titanium as a solid solution, it is desirable to have less hydrogen, but in reality it is oxidized by the oxygen contained at the same time, so the thickness of the paper or organic compound film made of C, H, O, and N should be as thin as possible. Since it is desirable to be thin, there is no lower limit. However, if the thickness exceeds 0.2 mm, the amount of carbide nitrides and oxides generated will increase, which will not only reduce the bondability during rolling but also cause solid solution in the rolled titanium or titanium alloy. The upper limit was set because the amount increases and hardens.

(Function) As shown above, in stack rolling of titanium, paper with a thickness of 0.2 mm or less or C, H
By sandwiching and rolling an organic compound film consisting of , O, and N, carbide nitride oxides are generated on the stacked surfaces, which are less harmful during hot rolling and function as a release agent to promote peeling at room temperature after rolling. Therefore, it is possible to carry out stacked rolling in which there is no fear of peeling during rolling and peeling is easy.

Although carbide nitride oxide remains at the interface after peeling, this can be removed by conventional methods such as pickling or polishing after peeling.

As an application example of the present invention, the laminated material 2 shown in Fig. 1 is made of titanium or a titanium alloy, and the present invention is also applied to the production of clad steel plates in which the surfaces of the laminated materials are butted together, laminated, hot rolled, and then peeled off. is possible. In the figure, ■ indicates that the base material 3 is a release agent, and 4 indicates an interpolation material for reinforcement.

(Example) Two pure titanium forged slabs of JI type 31 with a thickness of 30 mm were stacked and heated to 850°C, and hot rolled to a thickness of 2.5 mm in the stacked state. The film was then peeled off at room temperature under a light pressure of about 5%. At this time, various release agents were applied or sandwiched on the stacked surfaces of the forged slabs. The rolling and peeling results are shown in Table 1. As is clear from Table 1, in the method of the present invention, there was no peeling during rolling, and peeling by light reduction after hot rolling could be easily carried out. In the case of the aluminum plate used for comparison, it melted and peeled off during rolling, and in the case of a ceramic release agent, it could not be peeled off when applied thinly, but when it was applied thickly, it peeled off during rolling. In addition, in the case of paper with a thickness of 0.3 mm, rolling and peeling were possible, but the solid solution of C and O in titanium increased, and the surface hardened severely and the quality deteriorated. 0.7
In the case of paper with a thickness of mm, it peeled off during rolling.

Next, in the assembled slab of pre-rolled clad steel shown in Figure 1, a JTS Class 1 pure titanium plate with a thickness of 3.0 mm was used as the laminate material 2, and as the base material 1, 19.2% Cr and 0.4% Cu of
, 3 containing 0.6% Nb and 0.008% C
A titanium clad steel slab made of a stainless steel slab with a thickness of 0 nnb was stacked symmetrically with the titanium surfaces aligned, heated to 880°C, and hot rolled to a thickness of 4 mm in the stacked state. Then, it was peeled off under a light pressure of about 5% at room temperature. At this time, various release agents were applied or sandwiched between the overlapping surfaces of titanium and titanium. The rolling and peeling results are shown in Table 2.

As is clear from Table 2, in the method of the present invention, there was no peeling during rolling, and peeling by light reduction after hot rolling could be easily carried out.

In the case of the aluminum plate used for comparison, it melted and peeled off during rolling, and in the case of a ceramic release agent, it could not be peeled off when applied thinly, but when it was applied thickly, it peeled off during rolling. 0 again,
In the case of 3mm thick paper, rolling and peeling were possible, but
When a large amount of carbide oxides were removed,
The titanium layer of the laminated board disappeared locally. In the case of paper with a thickness of 0.7 mm, rolling (effect of the invention) According to the present invention, the paper is coated with C, H, O before rolling.

By simply sandwiching an organic compound film made of N, stacking rolling of titanium or stacking rolling of titanium clad steel, which is free from peeling during rolling and is easy to peel, becomes possible. As a result, not only the rolling process is simplified, but also the production of thin hot-rolled materials that can be substituted for cold-rolled materials and the rolling of single-sided titanium clad materials asymmetrical in the thickness direction are facilitated.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an assembled slab of clad steel before rolling, showing an application example of the present invention. 1... Base material, 2... Laminating material, 3... Release agent, 4...
...Interpolation material agent Patent attorney Masamitsu Akisawa and 1 other person

Claims (1)

[Claims] (1) In the manufacture of plate materials in which titanium or titanium alloy slabs are laminated, hot-rolled, and then peeled off, the laminated interface is made of paper or C, H, O, or N with a thickness of 0.2 mm or less. A method for laminated rolling of titanium and titanium alloys, characterized by hot rolling with an organic compound film sandwiched therebetween.