JPS60203377A - Production of titanium clad material - Google Patents

Abstract

PURPOSE:To obtain a titanium clad material having extremely good joint strength and workability in the stage of producing the titanium clad material of which the base metal is a ferrous metal by a roll method by interposing a spacer between an intermediate material and cladding metal together with the intermediate joint material consisting of a specific material between the base metal and the cladding metal. CONSTITUTION:A ferritic stainless steel or martensitic stainless steel is used as an intermediate joint material between a base metal and cladding metal with a titanium clad material of which the base metal is a ferrous alloy and the cladding metal is titanium or titanium alloy. A spacer consisting preferably of fine- diameter wires or coarse meshed wire net or the like consisting of the same material as the intermediate material and having about several mm. diameter is interposed between the intermediate material and the cladding metal and a blank titanium clad material is assembled together with the intermediate material. Said material is hot rolled by an ordinary roll method. The titanium clad material having extremely good joint strength and workability is stably produced by the above-mentioned method.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a titanium clad material having high joint strength and excellent workability more stably and reliably than the roll method.

1- In recent years, attention has been focused on the excellent corrosion resistance of titanium or titanium alloys, and titanium or titanium alloy T-cladding has been used as a base material for iron-based metal materials, which are relatively inexpensive and have good mechanical strength and workability. The use of titanium cladding materials and titanium lining materials, which have been relined and relined, is increasingly being used in all chemical equipment.

By the way, the conventionally known manufacturing method of titanium clad material using iron-based metal as a base material is as follows: 1. Explosives are fully detonated in an explosion chamber, and the base material and laminate materials placed opposite each other are bonded to each other under the impact pressure. “Explosion bonding method”, ■ Clean the bonding interface between the base material and the laminate, then assemble by welding so that the space at the bonding interface can be vacuumed and maintain it, or pack it into a pack material), then 0.1T
7, which is the general heating temperature during hot processing of titanium and titanium alloys after evacuating the bonding interface to below orr.
10- Heated to 00~950℃, hot rolled and bonded
■ After cleaning the bonding interface between the base material and the cladding material, the total interface is 0.5
Kf/-11! 1 Diffusion liquid method in which bonding is performed by heat treatment at a temperature of 700 to 90°C for about 30 minutes while pressurizing back and forth.
It can be roughly divided into three categories: , .

However, the solubility of all elements constituting general iron-based metals such as Fe, Cr, and Ni in titanium is relatively low;
Moreover, titanium has a strong bonding force (affinity) with other metal elements, including the above elements, and it is easy to form intermetallic compounds.
Since most of the intermetallic compounds formed are brittle and have extremely poor workability, it is difficult to use a rainbow base metal to diffuse the elements at the bonding interface, such as the 10-L method or the diffusion bonding method. In the rad manufacturing method, which involves bonding with laminated materials, the elements that make up all the iron-based metals diffuse and penetrate into the titanium, which also combines with titanium and forms fragile intermetallic compounds.
The tendency to form 'i' was more pronounced, and good bonding strength could not be obtained (), and only clad materials with extremely poor workability could be produced.

Because of this process, when trying to manufacture clad materials of titanium or titanium alloys and other metals (e.g. steel) using the "roll method" or "diffusion bonding method," the problem of weak diffusion at the bonding interface occurs. Ar is applied between the base material and the laminate material to prevent or suppress the formation of layers.

Attempts have also been made to insert a thin plate of Cu, Nb, Ta, V, Mo, Cr, N1, etc. or as an intermediate material for FF1K bonding71, and to apply a plating layer of these metals to the bonding interface. However, it was not possible to obtain a cladding material that satisfactorily satisfies both workability and bonding strength, and it also increased the manufacturing cost of the cladding material, so it has not yet been put into practical use. not present.

On the other hand, the "explosion bonding method" does not utilize the diffusion phenomenon caused by heating, so a weak diffusion layer consisting entirely of intermetallic compounds is not formed, and it is also difficult to apply strong impact pressure. Because a strong bond can be obtained through the process, it can be said to be the only method for manufacturing titanium clad material that is used industrially.

However, the explosive bonding method has limitations on product dimensions (area and plate thickness) due to various factors, such as the inability to manufacture thin plates, and it is also impossible to adopt the in-house production method. in,
Furthermore, there is a problem in that the manufacturing cost is high, and there is currently a need for a method for manufacturing titanium clad materials that overcomes these difficulties.

From the above-mentioned viewpoints, the present inventors have developed a cladding material that uses titanium or a titanium alloy as a cladding material and uses a ferrous metal such as carbon steel, low alloy steel, and stainless steel as a base material, and that is an excellent material. In order to find a way to mass-produce products with bonding strength and workability at low cost without being limited by shape or size, and to open the way to the development of products with new functions, we will particularly focus on product dimensions, etc. Focusing on the above-mentioned "roll method" which has relatively few restrictions and can be mass-produced, we investigated the formation of an intermetallic compound embrittlement layer at the joint interface that inevitably occurs when implementing these methods, and the degree of embrittlement. As a result of conducting research on the development of inexpensive means that can suppress the amount of metal to as small a range as possible, we found that, instead of using the well-known bonding intermediate material made of pure metal as mentioned above, we used ferrite, which is completely different from these. system
4- Stainless steel or martensitic stainless steel)
If a bonding intermediate material such as a thin plate made of This method prevents the formation of chemical layers, and also allows them to be firmly bonded, making it possible to obtain a titanium clad material with excellent bonding strength and workability comparable to those produced by the "one-burst bonding method." Based on this knowledge, a method for manufacturing titanium clad material with good bonding strength and workability was proposed in a patent application filed in 1983-17.
It was proposed earlier as No. 28.

However, from the table, when manufacturing titanium clad material using the roll method, when the material thickness (laminated material thickness + base material thickness) becomes thicker,
In the hot rolling heating process, it is necessary to heat the material for a long time to soak it up (for example, if the material thickness is 100 m, heating for at least 2 hours is required), but in this case, Even if ferritic stainless steel or martensitic stainless steel is inserted as a joining intermediate material, the diffusion prevention effect of the stainless steel thin plate joining intermediate material will be overcome, and the constituent elements of the joining intermediate material itself will be The present inventors believe that if titanium or titanium alloy composite material does not diffuse into the composite material, a fragile transition diffusion phase will eventually be formed in the composite material, which may cause problems in terms of use. This was revealed in subsequent research.

Therefore, the present inventors have developed a titanium clad material in which a joining intermediate material made of ferritic stainless steel or martensitic stainless steel is sandwiched between a base material of ferrous metal and a titanium or titanium alloy composite material. As a result of further research in order to completely prevent the above-mentioned diffusion during rolling heating and suppress the embrittlement of the joint interface of titanium clad products, we have found that when assembling titanium clad materials, there is a Diameter: If a spacer such as a wire as small as a bedding net or a coarse wire mesh is used, contact between the laminate and the joining intermediate material will be prevented during the heating of the materials in the hot rolling joining process, and therefore heating will not take place for a long time. We have come to the knowledge that even with this method, the formation of a brittle diffusion transition phase in the laminate does not occur, and it is possible to obtain a titanium clad material with extremely good bonding strength and workability.

This invention was made based on the above knowledge, and it is important to note that when manufacturing a titanium clad material using a roll method using iron-based metal as a base material and titanium or titanium alloy as a laminate material, the difference between the base material and the laminate material is By using ferritic stainless steel or martensitic stainless steel as the joining intermediate material, interposing a spacer between the joining material and the joining intermediate material, and assembling the crat material, and subjecting it to hot rolling, This method is characterized by the fact that titanium cladding materials with excellent bonding strength and workability can be produced stably at low cost, without the formation of a fragile diffusion transition phase at the bonding interface.

Note that "iron-based metals" here refers to all iron-based alloys such as carbon steel, low-alloy steel, and various stainless steels, and there are no particular restrictions on the type of "titanium alloys." .

-7= Furthermore, the term "roll method" refers to the commonly known method of producing crat material, which is the method described in Section 0 above.

The "ferritic stainless steel" and "martensitic stainless steel" used as joining intermediate materials in the method of the present invention are Fe-Cr-based or Fe-Or-M
o series 5US405 steel, 5US410L steel, 5US43
0 steel, 5US430F steel, 5US444 steel, etc., as well as ferritic stainless steel, 5US403 steel, and 5US410 steel.

5US410J1 steel, 5O8416 steel, 5US420J
1 steel, 5US420J2 steel, 5US431 steel, 5US4
This refers to any of the martensitic stainless steels indicated as 4OC steel, etc., and although the reason is still not completely clear, any of these ferritic stainless steels or martensitic stainless steels can be used as an intermediate for joining. Even when used as a material, it is superior to the “roll” method.
A titanium clad material having bonding strength and workability of 7 can be obtained.

9- 8- "Spacer" interposed between the laminate material and the joining intermediate material
The material may be of any shape, such as a thin wire with a diameter similar to that described above, or a coarse wire mesh, as long as it can provide a spacing similar to that of the floor between the joining material and the joining intermediate material.
In addition, the material is preferably ferritic stainless steel or martensitic stainless steel, which has the same quality as the joining intermediate material, but is not limited to these.It does not have a negative effect on the joining material or the joining intermediate material, and can withstand heat. As long as it is something you can get, there is no question about the ¥II category.

Next, this invention'f! :*Examples will be explained in comparison with Niji comparative examples.

(Example) First, as shown in Figures 1 and 2, the dimensions are 6m.
X150+nmX200ttrm, first in JIS standard
A pure titanium plate equivalent to a seed is used as the laminating material 1.1, and the dimension is 110
mX150+X200m, JIS standard 5B42 equivalent steel plate is used as base material 2, and 5US430 is used at the interface.
@-7) Prepare a plurality of titanium clad materials in which plate materials with a thickness of 0.1 wm are inserted as bonding intermediate materials 3, 3, and the total dimensions are: 2 tan x 26.2w x 15
JIS standard 1st of 0m or 2mX22.2mX150m
A base material 4 made of a pure titanium plate equivalent to a seed was welded and assembled into a four-piece shape.

At this time, there is a diameter of 2 wa between the joining material 1 and the joining intermediate material 3.
Two types were made: one in which a 5US430 wire was inserted as a spacer 5 (Fig. 1), and one without a spacer (Fig. 2).

Table 1 shows the chemical compositions of the laminate material, base material, and bonding intermediate material used.

The interfaces between the base material 2 and the laminate material 1 were each previously puff-polished and then cleaned by degreasing with acetone.

Thereafter, the nozzle 6 attached to one place on the plaster material 4 is used to remove 0. It was evacuated to less than I Torr and sealed.

Next, these were heated to 900°C for 1 to 5 hours, and the total thickness of the material was 26.2 m or 22.2 m + (material thickness) → 16.5 m →
A titanium steel plate was produced by hot rolling on a schedule of 12 sheets → 9.5 degrees.

Subsequently, this was subjected to an ultrasonic flaw detection test to confirm that the bonding condition of the joint surface was good, and on π, these clad steel plates were annealed as rolled and for 30 minutes at 700℃. A side bending test (bending medium diameter: plate thickness x 3 roller bending) was conducted to evaluate the joint strength and workability of each crat.

Table 2 shows the results of the bending tests obtained using this method. In Table 2, ○ mark: No peeling cracks occur at the joint interface, and the joint strength is good; × mark: Separation cracks occur at the joint interface, and the joint strength is poor. The results are shown for each of three samples.

It is clear from the results shown in Table 2 that if a spacer is not used and the hot rolling heating time is less than 1 hour, the clad product will have good bondability and workability. If the heating time is 2 hours or more, the joint will be bonded, but interface cracks will occur during the bending test, whereas if a spacer is used, it will not only take about 2 hours of heating but also 5 hours of hot rolling. It can be seen that even when heated, the clad product has good bending workability, and the bending workability improvement effect of using a spacer is remarkable.

Incidentally, Figure 3 is a microscopic structure photograph (magnification: 100x) of a titanium clad steel plate obtained by the method of test number 3 (comparative method) in Table 2, and Figure 4 is a micrograph (magnification: 100x) of the titanium clad steel plate obtained by the method of test number 3 in Table 2 (comparative method). Microscopic structure photograph of a titanium clad steel plate obtained by the method of test number 8 (method of the present invention) (magnification: 10
However, in the titanium clad steel sheet obtained by the comparative method without spacer, the bonding material (titanium) and the joining intermediate material (
In contrast, in the titanium clad steel sheet obtained by the method of the present invention using a spacer, even though the heating time during hot rolling was 5 hours, the diffusion phase was observed at the interface with SUS430 steel). The diffused phase was hardly observed.

From this work, from Figures 3 and 4, the spacer =
It is clear that the bonding strength and bending workability of titanium clad products will be significantly improved by the interfacial diffusion suppressing effect during hot rolling heating.

In this example, we have described an example in which 5US430 steel was used as the joining intermediate material, but good results were also obtained in examples using other ferritic stainless steels (for example, 5US41OL) or martensitic stainless steels. Needless to say, it was done.

As mentioned above, according to this invention, it is possible to mass-produce titanium clad material with extremely high bonding strength and excellent workability at a low cost by using the highly productive "roll method". This will bring about industrially useful effects, such as further expanding the fields of application of titanium clad materials.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing an example of assembling cladding material applied to the method of the present invention, Fig. 2 is a schematic diagram showing an example of assembling cladding material applied to the comparative method, and Fig. 3 is a schematic diagram showing an example of assembling cladding material applied to the comparative method. Fig. 4 is a microscopic photograph of the joint of the titanium clad steel plate obtained by the method of the present invention. In the drawings, 1... Laminating material, 2... Base material, 3... Joining intermediate material, 4... Pack material, 5... Spacer, 6... Nozzle. Applicant Nippon Stainless Co., Ltd. Agent Tomi 1) Kazuo and 1 other person Figure 1 4 Shelf 2 m JP-A-Sho GO-203377 (7) Figure 3 x 100 Figure 4 Mysterious theory, etc.

Claims (1)

[Claims] When manufacturing a titanium clad material using a roll method using iron-based metal as the base material and titanium or titanium alloy as the laminate material, ferritic stainless steel or martensitic stainless steel is used as an intermediate material to join the base material and the laminate material. A method for producing a titanium clad material, which comprises using a cladding material, assembling a cladding material with a spacer interposed between the cladding material and the joining intermediate material, and subjecting the cladding material to hot rolling.