JPH0818147B2 - Rolled clad plate manufacturing method - Google Patents

Description

The present invention relates to a method for producing a clad plate by hot rolling.

(Prior Art) JP-A-55-100890 and JP-A-55-100 as prior art
128390, JP 56-122681, JP 57-1095
In all of the methods for producing clad plates described in Japanese Patent No. 87, etc., the rolling materials are sandwiched, that is, the base material, the laminating material, the laminating material, the base material in this order or the covering material, the laminating material, the base material in this order. However, the plate thickness accuracy of the product was poor.
This is because the total plate thickness of the two clad plates or the total plate thickness including the covering material corresponds to the roll gap, and the roll gap does not determine the plate thickness of one clad plate. Further, in the conventional method of directly welding the four circumferences of the base material and the laminated material and heating and rolling, the plate thickness of one clad plate is determined as it is by the roll interval, so that the plate thickness accuracy is excellent, but a bonding failure is caused. It often happened.

(Problems to be Solved by the Invention) An object of the present invention is to provide a method for producing a hot-rolled clad steel sheet having excellent sheet thickness accuracy and bonding performance.

(Means for Solving the Problems) The present invention does not evacuate a joining scheduled portion, but an inert gas, a mating material or a powdery material which is equal to or more than the mating material,
The main point is to heat and roll the surfaces to be joined together while keeping them clean with a linear or flaky material.

The method of the present invention will be described in detail. As shown in FIGS. 1 and 2, a groove portion 4 is provided around a planned joining surface 3 between the base material 1 and the joining material 2. Is the same material as the joining material in the groove portion? Alternatively, a powdery, linear or flaky material 5 active to oxygen, nitrogen, carbon, hydrogen, etc. which is equal to or higher than that of the composite material is rolled, and the base material and the composite material are welded around the outer periphery 6 for four rounds. Then, an inert gas is injected from the nozzle 7 or the nozzle 7'which communicates between the surfaces to be joined to make a high pressure between the surfaces to be joined, and hot rolling is performed using a rolling material in which the nozzles 7 and 7'are sealed. The active material 5 has a function of preventing contamination of the surfaces to be joined due to welding heat and invading air during welding and assembly of the material for rolling, and invasion of contaminants between the surfaces to be joined due to damage of the welded portion during hot rolling. There is.
In addition, the inert gas filled at high pressure between the surfaces to be joined is
When the four-circle welded portion 6 is damaged during heating and rolling, it is possible to prevent the contaminants from leaking from the damaged portion and preventing the invasion of the contaminants between the surfaces to be joined and concentrating the substance that deteriorates the joining performance at the joining boundary. It has a function to prevent it. That is, when the planned joining surfaces are heated in a vacuum, for example, when the base material is steel and the mating material is titanium, hydrogen is present between the joining surfaces.
Carbon monoxide, carbon dioxide, etc. are generated by dirt on the surfaces of the composite material and the base material and substances vaporized and discharged from both metals, and at the titanium clad steel joint, titanium hydride or titanium hydride that deteriorates the joint performance is produced. Titanium carbide will be concentrated, but if an inert gas such as argon or helium is sealed in advance between the surfaces to be joined at a pressure higher than atmospheric pressure and heated, the pressure of the inert gas becomes even higher due to heating.
The amount of substances vaporized and discharged from both metals can be suppressed, and due to the damage of the welded portion at the initial stage of rolling, these substances with a deteriorated joint performance are squeezed out to the outside together with the inert gas.

The assembled material is easily damaged at the four-circle welded portion 6 during heating or rolling. In order to reduce the extent of this damage, the four-round welded portion 6 and the mating material 2 are welded four times around as shown in FIG.
It is desirable to cover and reinforce with the frame-shaped reinforcing frame 9 welded to. The assembly material having such a structure is effective when welding a metal such as a base material of steel and a composite material of titanium, which easily causes microcracks and blowholes in a welded portion,
Rolling bonding failure can be prevented. Frame-shaped reinforcement frame 9
It is desirable to keep the welded part 8 sound with the material of the base material together with the material of the base material.

In general, the base material is often inexpensive steel, and the composite material is more expensive than steel. In most cases, the composite material is a metal that is more active than the base metal and easily reacts with oxygen, nitrogen, carbon, hydrogen, or their compounds that are brought into the air or with the air. Degradable substances are easily generated. To prevent these contaminants from penetrating between the surfaces to be joined, an active material for trapping these contaminants is extended around the circumference. The active material is more active than either the composite material or the base material, or includes the active material of the composite material or the base material. The active material is then in powder, linear or flaky form with a large surface area so that contaminants can be quickly captured. These active materials may be mixed with the same material as the base material and the mating material, or may be extended at appropriate intervals to the entire periphery of the surfaces to be joined, the nozzles 7, 7 ', and the gas flow paths 10, 10'. Most desirable, most effectively prevent contamination of the surfaces to be joined.

(Example) Table 1 shows examples of the conventional method and the method of the present invention in comparison.

In the method 1 of the present invention, the material assembly structure shown in FIGS. 1 and 2 is used, and ribbon-shaped titanium having a cross section of 0.5 × 5 mm is used as the active material, and argon is blown between the surfaces to be joined at a pressure of 5 kgf / mm ^2. , The nozzle is sealed, and hot rolled. Invention method 2
Then, only the frame-shaped reinforcing frame 9 is added to the method 1 of the present invention. The conventional method 2 is different from the method 1 of the present invention in that an active material is not used and the pressure between the surfaces to be joined is reduced to 10 ⁻¹ torr. In the conventional method 1, the two assembly materials of the conventional method 2 are joined together by the plate surfaces of the laminated material 2 and the base material 1 is welded and fixed in the periphery. In the conventional method 2, the welded portion 6 of the base material and the laminated material may be broken during heating and rolling, and the shear strength of the joint boundary is 0.
Since there are a wide range of areas, the area can be industrialized only under limited conditions. In place of this, generally, Conventional Method 1 has been industrialized and the shear strength has been improved, but the clad plate thickness deviation (= maximum clad total thickness − minimum clad total thickness) is as large as 1.2 mm. , It is necessary to finish by cutting to make the clad plate thickness uniform. In the methods 1 and 2 of the present invention, the shear strength is stable at a high level and the clad plate thickness deviation is as small as 0.3 mm, which is excellent. Although there is no clear difference between the methods 1 and 2 of the present invention, the method 2 of the present invention can be regarded as industrially advantageous for stabilizing the shear strength at a high level.

(Effects of the Invention) As described above, according to the present invention, it is possible to improve the plate thickness accuracy and the joining performance of the rolled clad plate. The method of the present invention is based on the completely opposite idea to making a vacuum between the surfaces to be joined, which is the conventional method. When the welded portion is broken by applying a high pressure with an inert gas between the surfaces to be joined, a gas flow is assembled. It can be directed from the inside to the outside to prevent contamination of the surfaces to be joined. In the method of the present invention, when the welded portion is not damaged during hot rolling, the high-pressure gas containing an inert gas as a main component is compressed at the side edges and front and rear edges, and the surface of the joining surface during hot rolling It prevents the embrittlement substance from being concentrated.

(Application field of the invention) Although the above description exemplifies the case where the titanium clad steel plate is manufactured by rolling, the method of the present invention uses a titanium alloy
Applicable to zirconium or zirconium alloys, aluminum or aluminum alloys, copper or copper alloys, etc., such as steel or steel alloys and other base materials that are difficult to weld and combinations of base materials and stainless steel and carbon steel that are easy to weld Also applicable to combinations of copper and copper alloys. Further, it can be applied not only to the production of a plate-shaped clad material but also to the production of a rod-shaped, shaped or tubular clad material.

[Brief description of drawings]

FIG. 1 is a plan view of an assembly material for rolling used in the present invention, and FIG.
The drawing is a sectional view taken along the line AA in FIG. 1, and FIG. 3 is an explanatory view in the case of the second invention in which a frame-shaped reinforcing frame 9 is added to FIG. 1 ... Base material, 2 ... Laminated material, 3 ... Void between planned surfaces,
4 …… Grooves around the surface to be joined, 5 …… Powder, linear or flaky active material, 6 …… Four-round weld of base material and mating material, 7,7 ′ …… Nozzle, 8 …… Welded portion of base material and frame-shaped reinforcing frame, 9 ... Frame-shaped reinforcing frame, 10, 10 '... Gas flow path.

Claims (4)

[Claims] 1. A groove is provided around a surface to be joined between a base material and a mating material, and the mating material or a powdery, linear or flaky material which is more active than the mating material is extended in the groove. The base material and the mating material are welded around the outer periphery for four rounds, and an inert gas is injected from the nozzle that communicates between the surfaces to be joined to make a high pressure between the surfaces to be joined and heat-rolled using a rolling material in which the nozzle is sealed. Clad plate rolling method. 2. The steel according to claim 1, wherein the base material is steel or a steel alloy, the composite material is titanium or a titanium alloy, and the material to be extended in the groove is titanium in the form of powder, wire or flakes. The method for producing a clad plate by rolling according to item 1. 3. A groove portion is provided around a surface to be joined between the base material and the composite material, and the composite material or a powdery, linear or flaky material which is more active than the composite material is extended in the groove. The base material and the mating material are welded on the outer periphery for four rounds, and the four circumference welded portion and the peripheral edge of the mating material are covered and reinforced by a frame-shaped reinforcing frame welded to the base material, and the nozzles communicating between the joining surfaces are connected to each other. A method for rolling and manufacturing a clad plate in which an active gas is pressed in to increase the pressure between the surfaces to be joined and the nozzle is sealed to heat and roll using a rolling material. 4. The base material is steel or a steel alloy, the composite material is titanium or a titanium alloy, the frame-shaped reinforcing frame is steel or a steel alloy, and the material to be extended in the groove is powdery, linear or flaky titanium. The method for producing a clad plate by rolling according to claim 3, wherein: