JPH0669630B2 - Method for producing titanium clad steel sheet using nickel as an intermediate contact material - Google Patents

Description

The present invention relates to a method for producing a titanium clad steel sheet.

(Prior Art) Steel has been used for a wide range of applications since ancient times because it is inexpensive and has good mechanical, thermal, and electrical properties.
However, steel has a fatal drawback that it rusts or corrodes in a short time when used as it is. Titanium, on the other hand, has significantly better corrosion resistance than steel, so it solves the problems of corrosion and rust prevention, but other properties such as thermal conductivity are quite different from those of steel. It is not always easy to completely replace it with. Furthermore, titanium is significantly more expensive than steel, so it must be said that it is difficult in terms of resources and economy.

As a method of solving these problems, clad steel having a titanium surface and a steel center portion is used. The clad steel uses carbon steel or stainless steel that matches the desired characteristics as the base material, and titanium that has excellent corrosion resistance on the surface, so that it has excellent corrosion resistance and satisfies the desired characteristics. Therefore, it is widely used in chemical devices such as heat exchangers.

There are roughly two types of so-called clad steel plate manufacturing methods. That is, it is a so-called cast-in method in which compounding is performed at the molten steel level and a method of joining at the solid phase level.

In the case of titanium clad steel, when a brittle iron-titanium intermetallic compound or a layer such as TiC is formed at the interface between titanium and steel, the layer cleaves at the interface. Therefore, the casting method performed at the molten steel level cannot be applied, and joining at the solid phase level is adopted. Above all, the method by explosion bonding is the most widely used method at present because it does not use an intermediate contact material and has high reliability in terms of bonding strength.

However, since the explosive landing method uses the power of a powerful explosion, it cannot be implemented anywhere, and usually has to be done in secluded mountains. Moreover, it is a very expensive material because it is not suitable for mass production.
Further, the size of the explosive deposition method is limited, and it is particularly difficult to manufacture a thin plate.

The pressure welding method is advantageous over the explosive deposition method because it has high productivity and allows the plate thickness to be relatively freely set, and the conventional manufacturing process can be applied. However, in the method using pressure welding, it is very likely that a brittle layer such as an intermetallic compound is formed at the bonding interface, and if an oxide or the like is present at the interface, bonding becomes impossible. Particularly in the case of hot pressure welding, the risk of these increases because the diffusion rate and the oxidation rate are fast.

As a method of bonding while suppressing the formation of a brittle intermediate layer at the interface, JP-A-62-6783 has a limitation of hot rolling heating conditions,
Further, for example, in JP-A-55-48468, JP-A-57-109588, JP-A-57-112985, and JP-A-57-192256, a plate or a plate made of pure iron, nickel, steel or the like is formed at the clad interface. A method of sandwiching a foil as an intermediate medium contact material has been proposed. Further, JP-A-52-13460 discloses a method of sandwiching an intermediate medium contact material on the boundary surface by plating.

The role of the intermediate contact material in these methods is to suppress the reaction between titanium and carbon or iron in the steel, and does not form an intermetallic compound with the intermediate contact material.

On the other hand, in order to prevent the oxidation of the bonding interface, there is no suitable method other than vacuuming at least the mating surfaces or setting an inert atmosphere. For example, in Japanese Patent Laid-Open No. 57-109588, it is an essential condition to make the environment a vacuum of 1 Torr or less. For this reason, it is not always easy to take advantage of the features of the clad steel that it is not possible to reduce the cost and the cost is low.

Therefore, the titanium clad steel plate is usually used only as a thick plate in a chemical reaction device in which the corrosion resistance of titanium is essential.

In the case of clad steel plates such as stainless steel, a method of welding the mating surfaces and then rolling is proposed, but in the case of titanium clad steel plates, an intermetallic compound of iron and titanium cannot be formed and applied. .

In addition to this, as a method for preventing the oxidation of the bonding interface, JP-A-57-112985 proposes to cover the interface with cracks. However, since special equipment is required, the cost cannot be reduced.

On the other hand, the present inventor is a method of joining titanium and steel by forming a molten intermetallic compound of titanium and copper at the interface between titanium and steel, and squeezing out the oxide and the like together with the molten metal compound by reduction. Invented
1-122677).

According to the present invention, it is possible to inexpensively manufacture a titanium clad steel plate in the atmosphere. The role of the intermediate contact material in this method is to react with titanium to form an intermetallic compound, thereby creating a melt layer at the interface, and using it as a medium for squeezing out air and oxides. . Therefore,
Unlike the conventional way of thinking, the thickness of the intermediate contact material has been oriented toward the thicker side. In this respect, even if the same intermediate medium contacting material as the conventional one is used, the technical idea and the constitution of the invention are different from the conventional disclosed technology.

By the way, the solid-phase reaction due to the mutual diffusion of titanium and copper is quite fast. For this reason, it is advantageous that the heating time is short during joining when the intermetallic compound plays an important role, but after the joining where the intermetallic compound is unnecessary, the intermetallic compound grows thicker. In addition, the degree of freedom has to be sacrificed such that the annealing conditions are limited.

(Problems to be Solved by the Invention) A common drawback of the above-described conventional methods is that, for the purpose of preventing oxidation of the interface, it is necessary to perform treatment such as covering the mating surfaces with a vacuum or an inert gas. The cost is inevitably high.

The present invention improves the premature growth of an intermetallic compound, which is a drawback of JP-A-1-122677, which is directed to perform solid phase bonding in the air to form a clad in order to reduce cost, and manufacture It expands the degree of freedom of conditions. That is, the present invention provides a method for producing a titanium clad steel sheet, which comprises using an intermetallic compound of nickel and titanium in the joining in the atmosphere to remove the oxides produced at the interface and joining the titanium clad steel sheet.

(Means for Solving the Problems) It is important for the present inventors to remove the atmosphere from the interface in order to prevent the formation of oxides on the mating surface. For that purpose, non-oxidizing substances other than the atmosphere should be removed. I thought it could be achieved by filling. Based on this idea, as a result of various studies on non-oxidizing substances, it was found that a low-melting substance such as molten metal can be used (Japanese Patent Application Laid-Open No. 1-122677). That is, since the mating surface is not a perfectly smooth surface in the strict sense, even if the intermediary medium contacting material is inserted, if it is solid, air will always remain by simply mating. However, if a liquid substance is filled, air can be expelled even if a non-contact portion is formed on the mating surface.

Various alloys and compounds are conceivable as the intermediate medium contact material sandwiched between the mating surfaces. Copper is used in JP-A-1-122677, but nickel or nickel alloy is used in the present invention. That is, when nickel or a nickel alloy is sandwiched between the mating surfaces, the eutectic temperature of titanium and nickel is reached at about 950 ° C. and melting starts. On the other hand, at the interface between steel and nickel, iron and nickel diffuse and penetrate into each other, resulting in a strong bond.

However, if the mating surfaces are in a molten state indefinitely, joining is impossible, and even if the molten intermetallic compound phase of titanium and nickel is solidified, the purpose cannot be achieved.

Therefore, in the present invention, reduction is performed in a temperature range in which a molten layer of titanium and nickel is molten, and an air layer slightly remaining at the same time as the excess molten intermetallic compound is squeezed out from the end.

The growth rate of the intermetallic compound of titanium and nickel is about 1/3 of the growth rate of the intermetallic compound of titanium and copper, and it is possible to increase the annealing temperature in annealing after hot rolling. It was predicted that they would be equally advantageous.

Next, the behavior of the titanium clad steel manufacturing process according to the present invention will be described with reference to FIG.

In the production of titanium clad steel by the method of the present invention, as shown in FIG. 1, first, nickel or nickel alloy 3 in which titanium or titanium alloy 2 which is a laminated plate is used as an intermediate medium adhering material on steel 1 which is a base material. Sandwiched between them and the ends are partially fixed by welding or the like.

In this state, it is heated to a temperature higher than the melting point of the intermetallic compound of titanium and nickel to form an intermetallic compound by solid-phase reaction and at the same time melt. Next, before the intermetallic compound is solidified, at least one pass of reduction is applied to squeeze out excess intermetallic compound, air, etc. from the end. As a result, the minimum amount of nickel or nickel alloy sufficient to fill the unevenness of the surface remains on the mating surface, and titanium or the titanium alloy and steel are joined by pressure welding.

Further, since the air remains at the interface, the thin oxide layer formed on the surfaces of nickel, titanium and steel is squeezed out at the same time as the molten intermetallic compound of titanium and nickel. Since the oxide remaining at that stage is very small, it is reduced by the titanium of the composite material by the subsequent rolling, and oxygen is diffused and solid-dissolved in the titanium.

Next, in order to examine the possibility of joining, in the air, titanium and steel 10 mmφ rods were stacked with a nickel plate in between, and 1 kgf / mm ²
It was pressed with the initial load of. As a result, the nickel plate was simply deformed without joining at 750 ° C or lower.
Bonded above ℃.

However, at 950 ° C or less, the fracture strength of the joint surface was several kgf / mm ² or less, and it easily fractured. At temperatures above 950 ° C, a molten layer of an intermetallic compound of titanium and nickel was formed at the interface, and the fracture strength of the joint surface was also improved to 10 kgf / mm ² or more. Also 1050
At temperatures above ℃, the molten layer of the intermetallic compound became thicker, and titanium and steel were joined in such a way that they slip and bend at the joint surface.

The present invention has been completed based on the above findings.

That is, the present invention is 1) in the production of a clad steel sheet in which the base material is steel and the composite material is titanium or a titanium alloy, and nickel or a nickel alloy containing nickel in an amount of 30% or more between the base material and the composite material is used as an intermediate medium. Sandwiched as material, over 950 ℃ 1050
A method for producing a titanium clad steel sheet using nickel as an intermediate contact material, which is obtained by rolling at least one pass at a rolling reduction of 10% or more at a temperature of ℃ or less and squeezing out and joining a molten intermetallic compound layer of titanium and nickel. .

Furthermore, instead of sandwiching the intermediate medium contact material as a foil or thin plate, if it is brought into close contact with the steel surface by plating or thermal spraying, the bondability between the steel and the intermediate medium contact material will dramatically improve, and the required reduction ratio It has been found that the lower limit expands. This is because the adhesion between steel and nickel is improved by plating or thermal spraying, and as a result, oxidation between the nickel and steel or a large amount of air does not enter during heating.

2) Based on this knowledge, 2) In the production of clad steel plate whose base material is steel and whose composite material is titanium or titanium alloy, nickel or nickel alloy containing 30% or more of nickel is underplated on the surface of the base material steel. Directly plating at least 10 μm or more in thickness, and then laminating titanium or titanium alloy, which is a matching material, on the plated surface, and at a temperature of more than 950 ° C and less than 1050 ° C, a reduction rate of 10% or more. At least one pass rolling, and squeezing out the molten intermetallic compound layer of titanium and nickel to join, and a method for producing a titanium clad steel sheet using nickel as an intermediate medium contact material, and 3) the base material is steel and the composite material is titanium or In the production of a clad steel plate which is a titanium alloy, nickel or a nickel alloy containing 30% or more of nickel is directly sprayed onto the surface of the base steel at least 10 μm or more, After that, the titanium or titanium alloy, which is a composite material, is layered on the surface that has been sprayed.
At least 1 at a temperature of 050 ℃ or less and a rolling reduction of 10% or more
A method of manufacturing a titanium clad steel sheet using nickel as an intermediate contact material, which has been pass-rolled and squeezed out of the molten intermetallic compound layer of titanium and nickel and joined, has been completed.

The clad steel sheet produced according to the present invention can be a so-called cold rolled finish clad steel sheet by appropriately performing pickling descaling cold rolling temper rolling annealing. The annealing after cold rolling can be carried out in accordance with the annealing of a pure titanium plate, but unlike pure titanium, it can also be carried out in the atmosphere or an inert gas.

Based on this knowledge, 4) the titanium clad steel sheet produced by the above production method, descaled, and then cold rolled, a method for producing a titanium clad steel sheet using nickel as an intermediate contact material, and 5) this titanium clad steel sheet. Is a method for producing a titanium clad steel sheet using nickel for annealing and descaling as an intermediate medium contact material, and 6) a titanium clad steel sheet produced by this production method with nickel for temper rolling of 5% or less as an intermediate medium. A method for producing a titanium clad steel sheet used as a bonding material, and 7) a method for producing a titanium clad steel sheet using nickel, which is annealed in the air or in an inert gas, as an intermediate medium contact material have been completed.

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

Since nickel or nickel alloy as the intermediate medium contact material needs to be diffused and solid-dissolved with titanium as the composite material and melted, the nickel content is set to 30% or more.

In order to squeeze out the intermetallic compound on the boundary surface from the end portion by pressing, the intermetallic compound needs to be melted. Therefore, the heating temperature before the reduction is limited to a temperature range above the eutectic melting point of the intermetallic compound of titanium and nickel, that is, a temperature exceeding 950 ° C. However, if the joining temperature is too high, not only the solid-phase reaction of titanium and nickel proceeds too much to reduce the thickness of titanium, but also the viscosity of the molten layer decreases and slippage occurs without joining, The temperature was 1050 ° C.

This reduction can be achieved with just one pass, and 2
Although there is no obstacle even if it is more than the pass, if it is not joined or if it is not joined, even if it is joined, sufficient quality as a clad steel cannot be obtained.

If the rolling reduction is less than 10%, the squeezing of the intermediate contact material is insufficient, so the rolling was limited to 10% or more.

If the thickness of the nickel layer formed by plating or thermal spraying is less than 10 μm, the amount of the intermetallic compound of titanium and nickel formed by reacting with titanium is small, which is insufficient for simultaneously squeezing out oxides and air at the interface.

In the case of plating or thermal spraying, an intermetallic compound different from the intermetallic compound of titanium and nickel may be generated between titanium and titanium by performing the surface treatment, and there is a risk of deteriorating the bondability of the interface. Therefore, it is limited to no undercoating or undercoating.

The temper rolling after cold rolling annealing is set to the upper limit because work hardening proceeds if it exceeds 5% and the ductility required as a cold rolled steel sheet cannot be secured.

(Operation) As described above, a molten titanium-nickel intermetallic compound is produced at the interface between titanium and steel, and the molten intermetallic compound is squeezed out by rolling to produce titanium-clad steel without using vacuum. It became possible to do. This is a method of producing a molten intermetallic compound at the boundary surface in order to remove the oxide, which is the largest factor that inhibits joining, from the boundary surface when manufacturing a titanium clad steel plate, and devises an operation to squeeze out with it. This is because it is incorporated into the invention as That is, when the molten intermetallic compound is squeezed out, the oxide and the like formed at the interface are also squeezed out at the same time.

Whereas the conventional idea of removing oxides in the method for producing a titanium clad steel sheet was to not generate the oxides on the boundary surface, the present invention has changed the idea to remove the generated oxides. is there. By adding a means for removing oxides generated in the manufacturing process, it is no longer necessary to prevent the generation of oxides against the conventional laws of nature.

As a result, for example, expensive equipment such as a vacuum pump and a vacuum tank is not required, the process for making a vacuum is eliminated, and the work can be performed in an atmospheric environment, so that the manufacturing is significantly simplified.

Further, in the present invention, since nickel is used as the intermediate medium contact material,
The degree of freedom of the annealing conditions has been expanded from that of the invention disclosed in JP-A-1-122677 using copper.

The titanium clad steel according to the present invention did not differ in quality from the titanium clad steel manufactured by utilizing the conventional vacuum method. However, a layer with a high nickel content was found in titanium and steel near the interface, and it was presumed that nickel dissolved and diffused in both the base steel and the titanium titanium. However, no deterioration of the quality of the clad steel was observed, including the bondability of the interface.

2 and 3 show an embodiment of assembling a raw material before rolling for producing titanium clad steel by the method of the present invention. 2 is a sandwich type, and FIG. 3 is a semi-sandwich type assembly sectional conceptual diagram.

In the figure, 1 is steel such as carbon steel and stainless steel which is a base material, and 2 is titanium or titanium alloy which is a composite material. Reference numeral 3 is nickel or a nickel alloy, which is an intermediate medium contact material, and is a thin plate or foil, or a plating film plated on the surface of the base material of 1 or a sprayed sprayed film. Reference numeral 4 is a backing plate, 5 is a separating agent, 6 is a waste material, 7 is a welded portion, and 8 is a reservoir for intermetallic compounds.

(Example) (1) A 3.0 mm thick pure titanium plate of JIS class 1 as a bonding material, a nickel plate of 0.7 mm thickness having a purity of 99.9% or more as an intermediate contact material, and a 19.2% Cr as a base material. , 0.4% Cu, 0.6%
A 30 mm thick stainless steel slab containing Nb and 0.008% C was laminated in a sandwich form
It was covered with a steel plate having almost the same composition as the base metal having a thickness of 1.0 mm through an Al ₂ O ₃ based separating agent, and about half of the side surface of the base metal was welded and fixed.

The surfaces of these materials were machine-finished to H _max of 5 μm or less and then assembled. Then, heat to 1020 ℃ and 1000 ~
One pass each of 14% and 18% reduction was performed at 960 ° C., and then hot rolling was performed between 950 ° C. and 730 ° C. until the total sheet thickness became 4 mm. As a result, molten intermetallic compounds of titanium and nickel were squeezed out from the portions not welded and fixed in the first pass and the second pass. However, rolling was completed without peeling.

The hot-rolled sheet can be cut with Al ₂ O ₃
Separation was performed at the separating agent part, and titanium clad steel plates each having a thickness of about 4 mm could be manufactured. The produced titanium clad steel had no problems in terms of interface bondability, quality as a titanium clad steel, corrosion resistance of a laminated material, and mechanical properties of a base material.

As a comparison, without using nickel, titanium was simply put on stainless steel, a steel piece was assembled in the same manner as above, and rolling was performed. However, it was completely peeled off and clad steel could not be manufactured. The part that was partially joined was also easily peeled off when subjected to bending back after cooling, and the bondability was poor.

(2) 11.0 mm thick pure titanium plate of JIS class 1 as a mating material,
A 1.0 mm thick nickel plate with a purity of 99.9% or higher is used as an intermediate medium contact material, and a 50 mm thick carbon steel slab containing 0.131% C as a base material is stacked in a sandwich form. _The same combination of titanium, nickel and carbon steel was overlaid via a ₂ O ₃ + ZrO ₂ based separating agent, and a steel ingot of the same composition as the base material was sandwiched between the end faces and side faces and fixed by welding to assemble a slab.

At this time, air-releasing unwelded holes were left in the four corners of the slab.
The surfaces of the pure titanium plates of the base material and the laminated material were assembled by shot pickling with H _max of 80 μm or less and 120 μm or less, respectively, and the nickel plate was as cold-rolled with H _max of 5 μm or less.

After that, heat it to 1000 ℃ and reduce it by 24% at 980 ～ 960 ℃.
I did a pass. At this time, the molten intermetallic compound of titanium and nickel was squeezed out from the unwelded portion after the rolling. Then, hot rolling was performed between 930 and 750 ° C until the total plate thickness became 5 mm.

Hot-rolled sheet is made of Al ₂ O ₃ +
Separated at the ZrO ₂ separating agent part, it was possible to manufacture a titanium clad steel plate each having a thickness of 2.5 mm. This titanium clad steel plate had no problems in terms of the bondability at the interface, the quality of the titanium clad steel, the corrosion resistance of the laminated material, and the mechanical properties of the base material.

The titanium clad hot rolled steel sheet was descaled and cold rolled to a thickness of 1 mm. After that, 700 ℃ -1min in the atmosphere
Was annealed and descaled by pickling. Further, the cold-rolled sheet was temper-rolled at 0.5%.

The titanium clad cold-rolled steel sheets produced by these have the same interface bondability as galvanized steel sheets, and there is no problem with the quality as titanium clad steel, the corrosion resistance of the laminated material, and the mechanical properties of the base material. It was

(3) A 3.0 mm thick pure titanium plate of JIS type 2 with a thickness of 3.0 mm was used as a base material, and nickel was sprayed on one side with a thickness of approximately 0.2 mm as the base material.
Contains 9.3% Cr, 0.4% Cu, 0.6% Nb and 0.008% C
A 30 mm thick stainless steel slab is stacked in a sandwich so that the titanium surface and the sprayed nickel surface face each other.Furthermore, the same composition as the 1.0 mm thick base material is placed on the titanium through the ZrO ₂ type separating agent. It was covered with a steel plate of, and about half of the side surface of the base material was welded and fixed.

Then, heat it to 1000 ℃ and reduce it by 16% at 980 ～ 970 ℃.
Passing was carried out, followed by hot rolling between 940 and 730 ° C until the total plate thickness became 3.5 mm. As a result, the molten titanium and nickel intermetallic compound were squeezed out from the portion not welded and fixed in the first pass. However, rolling was completed without peeling.

As for the hot-rolled sheet, the cover material was separated by cutting the end surface and the side surface, and a titanium clad steel sheet having a thickness of about 3.5 mm could be manufactured. The produced titanium clad steel had no problems in terms of interface bondability, quality as a titanium clad steel, corrosion resistance of a laminated material, and mechanical properties of a base material.

As a comparison, without using nickel, titanium was simply put on stainless steel, a steel piece was assembled in the same manner as above, and rolling was performed. However, it was completely peeled off and separated, and clad steel could not be manufactured. The part that was partially joined was also easily peeled off when subjected to bending back after cooling, and the bondability was poor.

(4) As a base material, a 4.0 mm thick JIS type 2 pure titanium plate was used as a base material, and one side was plated with about 100 μm of nickel.
A 25 mm thick carbon steel slab containing 0.007% C was laminated in a sandwich shape so as to face the titanium surface and the plated nickel surface, and further 1.0 mm from above the titanium via an Al ₂ O ₃ type separating agent. It was covered with a steel plate having almost the same composition as the thick base metal, and about half of the side surface of the base metal was welded and fixed. Then 10
Heat to 10 ° C and reduce 12% and 24% at 990-960 ° C to 1
I did a pass.

At this time, the molten intermetallic compound of titanium and nickel was squeezed out from the unwelded portion after the rolling. Then 920-780
It was hot-rolled between 0 ° C until the total sheet thickness became 3 mm. The cover material was separated by cutting the end surface and the side surface of the hot-rolled sheet, and a titanium clad steel sheet having a thickness of 2.9 mm could be manufactured.

This titanium clad steel plate had no problems in terms of the bondability at the interface, the quality of the titanium clad steel, the corrosion resistance of the laminated material, and the mechanical properties of the base material.

(Effects of the Invention) According to the present invention, it is possible to manufacture a titanium clad steel without physically creating a vacuum. As a result,
Since the production of titanium clad steel is technically easy and the cost is low, the excellent corrosion resistance of titanium can be enjoyed at a low cost, and the resource and economic benefits are great.

[Brief description of drawings]

FIG. 1 is an explanatory view of the assembling of a material before rolling for producing titanium clad steel by the method of the present invention, FIG. 2 and FIG.
FIG. 1 is an explanatory view showing an embodiment of assembling a raw material before rolling for producing titanium clad steel by the method of the present invention.

Claims (7)

[Claims] 1. In the production of a clad steel plate in which the base material is steel and the composite material is titanium or a titanium alloy, nickel or a nickel alloy containing 30% or more of nickel is used as an intermediate contact material between the base material and the composite material. Nip, rolled at a temperature of more than 950 ℃ and less than 1050 ℃, at least 1 pass rolling with a rolling reduction of 10% or more,
A method for producing a titanium clad steel sheet using nickel as an intermediate contact material, which comprises squeezing and joining molten intermetallic compound layers of titanium and nickel. 2. In the production of a clad steel plate having a base material of steel and a composite material of titanium or a titanium alloy, nickel or a nickel alloy containing 30% or more of nickel is underplated on the surface of the base material steel. Not directly at least 10
Plating with a thickness of μm or more, and then laminating titanium or titanium alloy, which is a matching material, on the plated surface, and 950 ℃
Titanium using nickel as an intermediate contact material, characterized in that it is rolled at least one pass at a rolling reduction of 10% or more at a temperature of 1050 ° C. or less, and the molten intermetallic compound layer of titanium and nickel is squeezed and joined. Manufacturing method of clad steel sheet. 3. In the production of a clad steel plate in which the base material is steel and the composite material is titanium or a titanium alloy, at least 10 μm or more of nickel or a nickel alloy containing 30% or more of nickel is directly sprayed on the surface of the base material steel. Then, titanium or a titanium alloy, which is a composite material, is superposed on the sprayed surface and rolled at least 1 pass at a temperature of more than 950 ° C and less than 1050 ° C with a reduction rate of 10% or more to melt the molten titanium and nickel. A method for producing a titanium clad steel sheet using nickel as an intermediate contact material, which comprises squeezing out and joining an intermetallic compound layer. 4. Production of a titanium clad steel sheet using nickel as an intermediate contact material, characterized in that the titanium clad steel sheet produced by the production method according to claim 1, 2 or 3 is descaled and then cold rolled. Method. 5. A method for producing a titanium clad steel sheet using nickel as an intermediate contact material, which comprises annealing and descaling the titanium clad steel sheet produced by the production method according to claim 4. 6. A method for producing a titanium clad steel sheet using nickel as an intermediate contact material, wherein the titanium clad steel sheet produced by the production method according to claim 5 is subjected to temper rolling at 5% or less. 7. The method for producing a titanium clad steel sheet using nickel as an intermediate contact material according to claim 5 or 6, wherein the annealing is performed in the atmosphere or an inert gas.