JPS5841688A - Production of titanium clad steel plate - Google Patents

Abstract

PURPOSE:To produce a titanium clad steel plate having high joining strength and bending workability by sandwiching a clad steel plate interposed with an intermediate joining material of specific metal between titanium and steel and further between base material of steel and cladding material of titanium. CONSTITUTION:A titanium plate 1, an intermediate joining material 2 and a steel plate 3 are joined by a conventional known explosive cladding method. Here, the material 2 is any one among niobium, niobium alloys, tantalum and tantalum alloys. The 3-layered clad steel 5 joined in such a way is hot-rolled, whereby a sheet of the 3-layered clad steel 5 is obtained. Said layer 5 is interposed as an intermediate layer between cladding material of titanium 6 and base material of steel 7, and the titanium plate 1' of the plate 5 and the titanium 6 as well as the plate 3' and the steel 7 are joined respectively by a known explosive welding method or a diffusion welding method. Such clad steel 8 is hot- rolled, whereby the thicknesses of the respective layers are changed respectively (1'', 2'', 3'', 5', 6', 7').

Description

Detailed Description of the Invention The present invention relates to a method for producing a titanium clad steel plate, and particularly to a method for producing a titanium clad steel plate that has excellent bonding strength and bending workability even after hot rolling and even after heat treatment at a high temperature after hot rolling. It is about the method.

In recent years, in addition to the conventional explosive crimping method, research has been progressing on manufacturing methods for titanium clad steel sheets, such as roll crimping and diffusion welding. Since compounds are generated and good bonding strength cannot be obtained, some methods have been proposed for diffusion welding, such as modifying the chemical composition of the base metal or inserting an intermediate welding material. However, it has not reached the point where it has been adopted industrially due to its small area.

Therefore, only titanium clad steel plates produced by the explosive crimping method are frequently used as materials for chemical equipment.

However, the titanium clad steel plate made by this explosive crimping method is F911, and the titanium plate manufactured commercially is F911.
1" is approximately 1.5 m or less, and anything longer than this is not commercially available. In addition, when the base material is a thin plate, there are limitations due to Vl: distortion that occurs after explosive crimping and a decrease in elongation of the base material. Furthermore, there were restrictions on the amount of explosives due to equipment capacity and noise pollution, and the Yuchitan clad steel plate, which had a large area, could not meet market demands.

In order to improve this, a method of hot rolling the titanium clad steel plate to produce a wide and long titanium clad steel plate has been attempted, but it has not yet been implemented industrially. .

For example, in Japanese Patent Publication No. 48-482, titanium clad steel plates with weak intermetallic compounds and complete joint areas are hot-rolled at approximately 475 to 900°C to achieve explosive bonding with excellent joint strength. A method for obtaining rolled clad steel sheet is disclosed.

However, since this method uses a lower rolling temperature than normal steel plate rolling temperatures, even though the deterioration of joint strength can be suppressed to some extent, the bending workability of the base material is significantly reduced due to excessive work hardening. Sometimes. This kind of IEJ
4 = When heat treatment is applied to improve the A properties, the bonding strength between titanium and steel is significantly reduced, and the shear strength may be less than 14”/2, the JIS standard value for titanium clad steel sheets. This is due to heat treatment, which causes the titanium steel to interdiffuse with each other and form a hard and brittle intermetallic compound, which reduces the bonding strength.

As a method for improving these drawbacks, a method has been proposed in which a medium is interposed between titanium and steel to prevent mutual diffusion between titanium and steel.

In addition to the above-mentioned diffusion welding, there are roll crimping, thermal spraying, and plating methods to manufacture multilayer titanium clad steel sheets with intermediate welding. Most preferably, the multilayer cladding is formed by crimping.

The presence of these 44 layers of intermediate bonding may cause new problems in clad steel plates that require welding if the thickness is thick, and since these intermediate bonding layers are generally selected from high-grade metals, the amount used is limited. Unless it is reduced as much as possible, it will not have any industrial value, so the thickness should be kept to the minimum necessary.

In addition, it is sufficient that the thickness of the intermediate material layer necessary to prevent diffusion is from several μ to several tens/j.

However, in the normal explosive crimping method, it is difficult to reduce the thickness of the welding material to less than one cylinder, and even if we used a welding material 44 with a thickness of 16, it would require 10 to 100 times more rolling. The total thickness of the clad steel before rolling must be 10 to 100 times greater than the total thickness of the clad steel after hot rolling, and it is not industrially possible to produce such a rad steel with substantially 1.

In order to improve these drawbacks, a truly excellent method was invented in Japanese Patent Application No. 128047/1983, previously filed by the present applicant.

That is, in this invention, first, nickel molybdenum, platinum, and gold are used to effectively prevent mutual diffusion.

A metal such as silver is explosively crimped with steel, and this clad steel plate is rolled by hot rolling to the minimum required thickness as a cladding material, and then this explosively rolled clad steel plate is bonded. A clad steel sheet with a thin layer of intermediate bonding material is made by interposing the material and the base steel as an intermediate bonding material, explosive bonding using a conventionally known explosive bonding method, and then rolling this. That's what you're trying to get.

However, even if the method of Japanese Patent Application No. 54-128047 is applied to titanium clad steel sheets, the bonding strength after hot rolling is still insufficient, and furthermore, the bonding strength decreases due to subsequent heat treatment. Subsequent experiments revealed the fact that it was further reduced.

In other words, the intermediate metals such as nickel, molybdenum, platinum, gold, and silver have excellent bonding performance with the base steel even after hot rolling, but they have excellent bonding performance with the composite material titanium. It was found that the bonding performance after rolling was sufficient.

The present inventor has finally completed the present invention as a result of conducting various experiments and tests in order to improve the drawbacks of titanium clad steel sheets produced by the explosion rolling method.

That is, the present invention involves interposing one of niobium, niobium alloy, tantalum, and tantalum alloy between titanium and steel as an intermediate bonding material to produce a clad steel plate, and further converting this clad steel plate into 11 material steel. This is a method for producing a titanium clad steel sheet, which is characterized by sandwiching and joining the titanium composite material and the titanium composite material, and then hot rolling.

Hereinafter, the method of the present invention will be explained in detail with reference to the drawings.

1 to 6 are explanatory diagrams according to the order of steps of the present invention, and in FIG. 1, ■ is a titanium plate, 2 is an intermediate welding material, and 3 is a steel plate. The intermediate layer 1g 4A' 2 is required to be a metal that does not form brittle intermetallic compounds between the titanium plate 1 and the steel plate 3 and has excellent malleability, and as a result of research, industrial pure niobium was selected.

Niobium alloy such as Nb - I Zr, N-Ti or industrial pure tantalum + Ta - Nb + Ta -
It has been found that tantalum alloys such as Ti are optimal.

Titanium plate 1. Intermediate junction old 2. The steel plates 3 are bonded together by a conventional explosive crimping method to form a three-layer clad steel 4 as shown in FIG. In this case, the explosive crimping method is as follows: First, the steel plate 3 and the intermediate medium welding material 2 are explosively crimped, and then the titanium plate 1 is explosively crimped on the surface of the intermediate medium welding material 2, and the three layers are explosively crimped at the same time. There is a method of crimping, but in the case of the former, the surface of the intermediate welding 4it 2 becomes rough during the first burst bonding, and
Furthermore, since niobium and tantalum are metals whose surfaces are easily activated, they are easily oxidized, and surface polishing is required to remove this oxide film, resulting in the loss of expensive materials. In comparison, in the latter three-layer simultaneous explosion bonding method, the intermediate bonding material 2 is the titanium plate 1.
Since an interlayer is formed between the metal plate 3 and the steel plate 3 at the same time as the pressure welding, even metals that are easily activated will not oxidize because they often come into contact with the atmosphere.
No need for polishing. In addition, it is highly efficient and does not cause skin irritation or monthly profit loss.

By hot rolling this three-layer clad steel, the three layers are 1' and 2', respectively, as shown in FIG.

3' to obtain a thin three-layer clad steel sheet 5.

The amount of reduction in hot rolling at this time varies depending on the rolling temperature, rolling time, rolling conditions, etc., but if the plate thickness is
It is preferable to reduce the pressure within a range of 5o.

Appropriate heat treatment may be performed after rolling.

The thus obtained thin three-layer clad steel plate 5 itself is used as an intermediate layer, and as shown in FIG. The titanium plate 1' of the thin three-layer clad steel plate 5 and the composite titanium 6 and the steel plate W and the base steel 7 are respectively bonded by an explosive crimping method, a diffusion welding method, a roll crimping method, or the like.

Here, the titanium material used in the present invention is a titanium alloy plate such as industrial pure titanium or Ti-α5Pd ft, and the steel material is 88% as specified by JIS.

SB material, SM material, 5USi, J and similar materials.

In the case of the above joining, there is also a method of joining Jυ copper steel 7 thin plates and triple-layer clad steel sheets 5, and then joining titanium 6 on top of that, but it is more efficient to join all three at the same time. No. 51<iJ: Shows the state of the clad steel 8 after welding.

Depending on the rolling capacity of the machine, the plate thickness of Clad Steel 8 is approximately 1/1.
Hot rolling was carried out in the range of 2 to 115 degrees, and the thickness of each layer was changed as shown in Figure 6 ('+2.8, 5,
6.7).

The hot rolling temperature in the present invention is
As disclosed in Publication No. 2, when heated to a temperature of 880° C. or higher, the crystal structure of titanium transforms from a close-packed hexagonal system to a body-centered cubic system, and the crystal grains become coarse. Furthermore, N2
, Ti2, 02, etc., and the physical properties of titanium itself deteriorate.

Therefore, hot rolling is performed at 475 to 900°C, preferably 65°C.
It is preferable to carry out the process in a temperature range of 0 to 870°C. If the rolling end temperature is low, the elongation, reduction of area, etc. of Iυ, 4:A steel may be low, and in this case, heat treatment is performed as necessary to restore the properties of the base steel. be able to.

As described above, when hot rolling is performed in the present invention, heating and rolling can be repeated several times, and intermediate annealing is also effective in preventing deterioration of the mechanical properties of the base steel. . In addition, when rolling the clad steel plate 9, it is also possible to finish the plate to a predetermined thickness while joining the composite titanium 6° thin three-layer clad steel plate 51 and the base steel 7 by rolling.
It is also possible to join the thin three-layer clad steel plate 5 and the base steel 7 by a roll pressure welding method, and further to join the composite titanium material 6 by another joining method.

In order to control the plate thickness of the intermediate medium coupling 2 in the clad steel plate 9 to several μ to several tens of μ by rolling, the first
Titanium plate 1 in the figure. It is necessary to fully consider the thickness of the steel plate 3, the rolling reduction when rolling the thin three-layer clad steel plate 5 in FIG. 3, and the rolling reduction from FIG. 5 to FIG. 6.

When the rolling test in Fig. 6 was carried out in the state of 1 inch of rolling, it was found that the standard value of titanium clad plate specified by JIS (+ 41 < 9/x or more) was fully satisfied. The titanium clad steel plate was further heat-treated at 625℃ x 1.511r and subjected to a shear test, and as a result, the bonding strength was confirmed to be higher than the above JIS standard value, and the tensile test and The bending test results demonstrated that the titanium clad steel plate has strong bonding strength and excellent bending workability.

Therefore, with the completion of the unexploded IIJ, even after hot rolling, d, and 1... after the heat treatment cape after rolling,
A method for manufacturing titanium clad steel sheets with excellent bonding strength and 1-pin bending force has been established.

Examples of the present invention and comparative examples will be described below.

Example 1 Commercial pure niobium board 2 tX 100mm"X
2 (1018m), commercially available 5B42 steel plate 25.m
mtX 10011111WX 200mm is bonded to the surface using explosive pressure bonding, and a commercially available titanium plate':'NnmtX 100amWX 20 is bonded onto the niobium surface.
0g" By joining one sheet using the explosion method 11: (5+2+25)1nm" X '1.00nnX'
One sheet of three-layer clad steel of 200111111" was prepared. After heating the three-layer clad steel of
5) A thin three-layer clad steel plate with dimensions of 200 mm x 5001 nm was prepared.

This thin three-layer clad steel plate and commercially available S, B42 steel plate 5
0 mm' x 200 mm W
500 mm 1" were joined by explosive crimping to create a 5-layer clad steel of titanium/titanium/niobium/steel/steel/ζ.

This 5-layer clad steel was heated at 850°C for 1 hour (z
2+008+11.0)mmX500m++WX 1.
000 mm titanium clad steel plate was created.

Table 1 shows the results of investigating the interfacial bonding strength of this titanium clad steel plate using a shear test. According to the test results, JIS
Standard value of titanium clad plate (14'/
It was confirmed that the bonding strength was sufficient to achieve 614 feet (614 feet and above).

Example 2 A Hichitan crank steel plate prepared under the same conditions as Example 1 was further heat-treated at 625° C. for 1.5 hours, and then the interfacial bonding strength was investigated by a shear test.

The test results are also listed in Table 1. ``Motoyuri'': Even if further heat treatment is applied after rolling, there will be only a slight decrease in bonding strength.
It was confirmed that the standard values for titanium clad plates specified by JIS were fully satisfied.

Comparative Example 1 Commercially available industrial pure nickel plate 2I+I+IIL×1010
01n x 200mm', commercially available 5B42 steel plate 25
-XIQ, OmmW x 200mm" surface by explosive crimping (111). This nickel clad steel was heated to 900°C.

and (0,4+5)fRmtX200♂×5001+l
A thin clad plate of I+IL was created.

This thin clad plate and commercially available 5B42 steel plate 50 gpB
LX 200 mm W

This four-layer clad steel was heated at 850° C. for 1 hour, and at the titanium/nickel interface, % of the area was exposed. A 1]rg cutting test piece was taken from the % part that had been joined, and the joining force was investigated. The results are also listed in Table 1. However, one of the three shear test pieces prepared peeled off during test piece processing and could not be tested. The remaining two shear values were also below the standard values specified in JIS.

Table 1 Shear test results

[Brief explanation of the drawing]

1 to 6 are explanatory diagrams according to the seventh aspect of the present invention. ■, 1'...Titanium plate 2.2'...Intermediate welding material 3
``...Steel plate 4...Three-layer clad steel 5...
...Archive plate three-layer clad steel plate 6.6'...Mixture titanium 7,1...IJ moon copper steel 8
... Clad steel 9 ... Clad steel plate patent applicant
Asahi Kasei Industries Co., Ltd. Representative Patent Attorney Hide Komatsu 177 Figure 1 Figure 2 Diagram 4
Fig. 5 441 - Fig. 3 r - Person 11) l' 2/ 3/ )゛) 1 1, l / 6th t1! ! 1

Claims (1)

[Claims] 16. Niobium and niobium alloy between titanium and steel. A clad steel plate is manufactured by interposing one of tantalum and tantalum alloy as an intermediate bonding material, and this clad steel plate is further sandwiched between 1υ old steel and a composite titanium material, and then heated. A method for manufacturing a titanium clad steel sheet, which comprises rolling.