WO2019148961A1

WO2019148961A1 - Method for preparing titanium-steel composite plate

Info

Publication number: WO2019148961A1
Application number: PCT/CN2018/119274
Authority: WO
Inventors: 曾周燏; 江姗; 党军; 李东晖
Original assignee: 南京钢铁股份有限公司
Priority date: 2018-02-02
Filing date: 2018-12-05
Publication date: 2019-08-08
Also published as: CN108326516B; CN108326516A; KR102225672B1; KR20200105522A

Abstract

A method for preparing a titanium-steel composite plate. The titanium-steel composite plate with excellent bonding performance is prepared by means of blank preparation, surface treatment, separation agent coating, symmetric blanking, electron beam welding, heating, rolling, straightening, and plate cutting processes. A spacer (2) is added to an interface between the titanium and the steel by means of a blanking process, such that titanium and steel in a composite blank do not completely contact with each other, element interdiffusion is prevented during a heating process, and the formation of brittle phases such as carbides and intermetallic compounds on the interface is controlled. Subsequently, an interface oxide film is corrupted by means of large-reduction rolling, such that the formation of a new titanium-steel bonding interface and full metallurgical bonding are achieved. In addition, fast cooling after rolling is performed to suppress further formation of brittle phases, such that a titanium-steel composite plate with excellent bonding performance and no brittle phases is prepared. Compared with methods requiring additional nickel or copper foils as intermediate layers, the method has simpler steps, lower costs, and excellent bonding performance.

Description

Method for preparing titanium steel composite board

Technical field

The invention belongs to the technical field of bimetal composite manufacturing, and relates to the preparation of composite plates, in particular to a preparation method of titanium steel composite plates.

Background technique

Titanium has excellent corrosion resistance. In most corrosive environments, its corrosion resistance exceeds that of stainless steel. Therefore, it is widely used in chemical plants, pressure vessels, heat exchangers, offshore platforms and aerospace. . However, titanium is expensive and increases the material cost of equipment manufacturing, which limits the use of titanium. The titanium steel composite plate combines the excellent corrosion resistance of titanium and the toughness of steel, and greatly reduces the use amount of titanium, saves cost, has high economic value and good application prospect.

At present, the main preparation methods of titanium steel composite plates include explosive composite method, explosion-rolling composite method and vacuum rolling composite method. The explosion composite method has noise pollution and environmental pollution, and is affected by the weather and has low production efficiency. It is not a green, environmentally friendly and sustainable production method. The vacuum rolling composite method is a production process in which a substrate and a cladding material are subjected to a good metallurgical combination by vacuum welding of a preform, which has high production efficiency, low pollution, low energy consumption and can produce a wide specification. Metal composite board. Therefore, the production of titanium steel composite panels by vacuum rolling composite method will be the future development trend.

However, when the titanium steel composite plate is prepared by vacuum rolling, due to the severe interfacial reaction between titanium and steel at high temperature, if the titanium and steel are directly rolled and composited, the composite interface is easy to produce brittleness such as Ti-Fe intermetallic compound and TiC. The phase greatly affects the bonding properties of the titanium steel composite panel. In order to suppress the brittle phase formation of the interface, an intermediate layer such as a nickel foil or a copper foil is usually added between the titanium and the steel to block the bonding of Ti and C or Ti and Fe, thereby enhancing the bonding strength of the titanium steel composite interface. For example, the disclosed patent 201510249152.X "High-temperature preparation method of titanium steel composite board with nickel as intermediate layer" and 201510247275.X "Preparation method of titanium steel composite board with high bonding strength" are all added with nickel foil as intermediate layer for rolling Titanium steel composite panels to obtain a good combination of titanium steel composite panels. However, the addition of the intermediate layer not only makes the production process cumbersome, but also increases the production cost. Therefore, it is necessary to find a suitable production process to prepare a high-combination titanium steel composite panel.

Summary of the invention

OBJECT OF THE INVENTION The present invention provides a method for preparing a titanium steel composite panel in order to solve the problem that the severe interface reaction of the conventional titanium steel composite panel produced by the vacuum rolling method affects the bonding property of the composite panel.

Technical Solution: A method for preparing a titanium steel composite board according to the present invention comprises the following steps:

(1) subjecting the surface to be composited of the substrate and the covering blank to a surface treatment;

(2) coating the non-composite surface of the cladding material obtained in the step (1) with a release agent, and drying;

(3) Selecting a piece of substrate obtained in step (1) as a blank, and the four sides of the blank to be composited surface are fixed by spot welding, enclosing a groove, and spot welding on the composite surface of the blank in the groove a plurality of laminations, then placing the non-composite surface of the two superposed materials obtained in the step (2) in the groove, and then using the other substrate obtained in the step (1) as the upper blank, the upper blank to be composited Spot welding fixed a plurality of laminations, and the upper blank to be composited facing down on the two covering materials, ensuring that the outer peripheral edges of the upper and lower blanks are flush with the outer edge of the sealing strip to form a symmetrical composite blank;

(4) welding the symmetric composite blank obtained in the step (3) under a vacuum environment;

(5) heating the symmetric composite blank obtained in the step (4);

(6) subjecting the symmetric composite blank obtained in the step (5) to hot rolling and cooling;

(7) The symmetrical composite blank obtained in the step (6) is straightened and cooled, and the split plate is cut to obtain a titanium steel composite plate.

In the step (1), the substrate is carbon steel or low-alloy high-strength steel, and the covering material is industrial pure titanium, such as TA1 and TA2, and the composition and properties thereof meet the corresponding standard requirements; Abrasive belt grinding or milling machine processing, the purpose of surface treatment is to remove the rust layer and oxide layer on the surface of the blank, so that the surface completely exposes the fresh metal.

In the step (2), the main component of the release agent is MgO powder.

In the step (3), the composition of the seal is consistent with the substrate, the width of the seal is 30-60 mm, and the height of the seal is the sum of the thickness of the two laminated titanium sheets and the thickness of the two laminated sheets; The sealing strip and the upper and lower blanks are each welded to a depth of 30 to 60 mm to provide sufficient weld strength to ensure that the composite billet is not cracked during the rolling process. Preferably, the seal has a width of 35 to 55 mm.

The component of the laminate in the step (3) is identical to the substrate, the laminate is a circular laminate, the laminate has a diameter of 10 to 30 mm, and a thickness of 0.5 to 2 mm; The laminations on the composite surface and the upper blank to be composited are placed in the same manner, and one lamination is placed every 0.5 to 1.5 m; preferably, the lamination position of the lower blank to be composited surface is to be composited with the upper blank. The lamination positions on the surface are one-to-one correspondence, which prevents the deformation of the titanium plate during the combined compacting process, and ensures that the titanium plate and the substrate are to be separated from the composite surface, and at the same time, after the spot welding, the oxide layer and the welding slag caused by the spot welding are polished to ensure the composite to be compounded. The surface is clean. Preferably, the laminate has a thickness of from 1 to 2 mm.

In step (4), the vacuum electron beam welding method is used for welding, and the vacuum degree during welding is less than 5×10 ⁻² Pa; the upper and lower blanks of the symmetric composite blank are welded to the gaps of the seal, the seal and the seal by welding. The welding depth is 30 to 60 mm.

The heating temperature in the step (5) is 850 to 930 ° C, and the heating time is controlled according to the thickness of the symmetric composite blank at 10 to 30 min/cm. Preferably, the heating temperature is 880 to 910 °C.

In the step (6), the conventional rolling and the rapid cooling after rolling are adopted, the descaling box is not descaled, the first pass descaling is performed, and the high speed steel is thrown after rolling. The final rolling temperature of the hot rolling is ≥700 ° C, and the rolling is performed by a large reduction amount, and the total rolling reduction ratio is ≥80%, wherein the single pass maximum reduction ratio is ≥20%. The cooling is rapid cooling or natural cooling of the air, the rapid cooling is performed at a speed of 2 to 20 ° C / s, the red return temperature is controlled at 400 to 700 ° C; when the total rolling thickness is > 16 mm, rapid cooling is used; When the total thickness of the rolling is ≤16mm, rapid cooling or natural cooling of the air is adopted.

The straightening and cooling steps in the step (7) are as follows: the rolled composite plate is straightened, and the upper and lower cooling beds are cooled, and the surface is cooled when the surface temperature falls below 300 ° C; The steps of cutting the sub-board are as follows: after cutting the head, the tail and the two sides of the composite plate by plasma, the upper and lower two-sided composite plates are separated, and then the single-sided composite plate is straightened, subjected to surface grinding, performance detection, and packaging treatment. After that, the titanium steel composite board product of the required specifications is finally obtained. The titanium steel composite board product has a total thickness of 6 to 60 mm, wherein the thickness of the cladding material is 0.5 to 5 mm.

Beneficial effects:

(1) The invention adopts a method of adding a lamination between titanium and steel in the process of forming a blank, completely separating the titanium from the heating process of the steel, blocking the interdiffusion of the elements in the heating process, and effectively preventing the brittleness of the interface TiC and TiFe. The formation of phase; through the large rolling, destroying the interface oxide film, forming a new bonding interface, and adopting rapid cooling after rolling to prevent the brittle phase from being formed again, thereby obtaining a titanium steel composite plate with high bonding performance.

(2) The invention directly seals the welding in the vacuum chamber environment, reduces the submerged arc sealing welding, drilling, vacuuming and the like of the traditional process, effectively prevents the oxidation of the composite surface by the submerged arc sealing welding, and has more vacuum degree. Guarantee.

(3) The invention effectively blocks the formation of brittle phase of the interface of the titanium steel composite plate by adding a lamination between the titanium and the steel composite surface, and the operation is simpler and the production cost is simpler than adding the intermediate layer nickel foil or copper foil. Lower, it is also possible to obtain high-combination titanium steel composite board products.

DRAWINGS

Figure 1 is a schematic view of a laminate placed on a surface to be composited of a substrate blank, wherein 1 is a substrate blank and 2 is a laminate;

2 is a microstructural view of the interface of the titanium steel composite panel of Example 2.

Detailed ways

Example 1

In this embodiment, a Q235B steel grade having a substrate blank thickness of 66 mm, an industrial pure titanium TA2 having a thickness of 6 mm of a cladding blank, and a TA2/Q235B composite panel having a thickness of 0.5+5.5 mm are rolled.

I. Surface treatment: The two composite parts of the Q235B substrate blank and the two TA2 cladding materials are polished to remove the rust layer and the oxide layer on the surface of the blank, so that the surface completely exposes the fresh metal.

II. Coating of the release agent: Apply the release agent to the unpolished surface of the coated material, and then dry the release agent.

III. Symmetrical composite blank: one of the base materials is selected as the blank, and the four sides of the surface to be composited are fixed by spot welding with a seal width of 30 mm and a thickness of 13 mm. The substrate to be compounded in the groove surrounded by the seal Place a circular lamination every 0.5 m (see the arrow distance of Figure 1), the lamination size is φ10 × 0.5 mm, and fix the lamination on the lower blank to be composited by spot welding; then the two cladding materials The non-composite surfaces are superposed and placed in the grooves. Then, another base material is used as the upper blank, and the laminated piece is spot-welded at the same position as the symmetrical composite surface to be composited, and then the upper blank is to be composited face down, and is placed on the top of the two laminated cladding materials to ensure the upper and lower base. The four sides of the material are flush with the outside of the seal, so that a composite blank to be sealed is formed.

VI, electron beam sealing welding: the assembled composite blank is sent to the vacuum chamber, and then the vacuum chamber is evacuated. When the vacuum chamber vacuum reaches 3×10 ^-2 Pa, the electron beam is used to seal the seal between the substrate and the substrate. The gap is welded, and the welding depths of the upper and lower blanks are both 30 mm, so that a composite blank having a total thickness of 145 mm is obtained.

V. Heating: The composite blank is sent to a stepping furnace for heating, the heating temperature is 900 ° C, and the total heating time is 240 min.

VI, rolling and cooling: rolling in a conventional manner, descaling without descaling, rolling descaling for the first pass. The total rolling reduction rate is 91.7%, the maximum reduction rate of the pass is 28%, the final rolling temperature is controlled at 720 °C, and the final rolling thickness is 12 mm. After rolling, the air is naturally cooled.

VII. Straightening and cutting sub-board: After straightening, the upper cooling bed is cooled, and the surface temperature is lowered to 300 °C. After cutting the head, tail and cutting, the upper and lower single-layer composite panels are separated, and then the single-layer composite panel is straightened, and then the surface of the cladding is polished to obtain a TA2/Q235B composite with a finished thickness of 0.5+5.5 mm. Board products.

After testing, the shear strength of TA2/Q235B composite board is about 272MPa, which has high bonding performance.

Example 2

In this embodiment, a Q345B steel grade having a substrate blank thickness of 100 mm, a TA2 industrial pure titanium plate having a thickness of the cladding material of 10 mm, and a TA2/Q345B composite plate having a thickness of 2+20 mm are rolled.

I. Surface treatment: The two composite surfaces of the Q345B substrate blank and the two TA2 cladding materials are polished to remove the rust layer and the oxide layer on the surface of the blank, so that the surface completely exposes the fresh metal.

III. Symmetrical composite blank: one of the substrates is selected as the blank, and the four sides of the surface to be composited are fixed by spot welding with a seal width of 45 mm and a thickness of 23 mm. The substrate to be composited in the groove surrounded by the seal A circular lamination is placed every 0.8 m, the lamination is φ20×1.5 mm, and the lamination is fixed on the lower blank to be composited by spot welding; then the two non-composite surfaces of the cladding are superposed and placed in Inside the slot. Then, another base material is used as the upper blank, and the laminated piece is spot-welded at the same position as the symmetrical composite surface to be composited, and then the upper blank is to be composited face down, and is placed on the top of the two laminated cladding materials to ensure the upper and lower base. The four sides of the material are flush with the outside of the seal, so that a composite blank to be sealed is formed.

VI, electron beam sealing welding: the assembled composite blank is sent to the vacuum chamber, and then the vacuum chamber is evacuated. When the vacuum chamber vacuum reaches 4×10 ^-2 Pa, the electron beam is used to seal the seal between the substrate and the substrate. The gap is welded, and the welding depths of the upper and lower blanks are both 45 mm, so that a composite blank having a total thickness of 223 mm is obtained.

V. Heating: The composite blank is sent to a stepping furnace for heating, the heating temperature is 850 ° C, and the total heating time is 360 min.

VI, rolling and cooling: rolling in a conventional manner, descaling without descaling, rolling descaling for the first pass. The total rolling reduction rate is 80.3%, the maximum rolling reduction rate is 25%, the finishing temperature is controlled at 790 °C, and the final rolling thickness is 44 mm. After high-speed steel casting after rolling, the composite board quickly enters ultra-fast cooling for cooling, the cooling rate is 4 ° C / s, and the red return temperature is 650 ° C.

VII. Straightening and cutting the sub-board: After straightening, the upper cooling bed is cooled, and the surface temperature is lowered to 300 ° C. After cutting the head, tail and cutting, the upper and lower single-layer composite panels are separated, and then the single-layer composite panel is straightened, and then the surface of the cladding is polished to obtain a TA2/Q345B composite panel with a finished thickness of 2+20 mm. product.

After testing, the shear strength of the TA2/Q345B composite board with the laminated blank is about 252 MPa, which has a high bonding performance. According to the comparative example 1, the same thickness of the TA2/Q345B composite board with the intermediate layer of nickel foil is added. The shear strength is also only 243 MPa, as shown in Table 1. It can be seen that the addition of the laminate can effectively block the interfacial reaction of the titanium steel and obtain a high shear strength. The interface microstructure of TA2/Q345B titanium steel composite plate is shown in Fig. 2. No unbonded area is found between titanium and steel, and the composite plate achieves good metallurgical bonding.

Example 3

In this embodiment, a Q370R steel having a base material thickness of 275 mm, a TA1 industrial pure titanium having a thickness of 25 mm of a cladding material, and a TA1/Q370R composite plate having a thickness of 5+55 mm are rolled.

I. Surface treatment: The two composite surfaces of the Q370R substrate blank and the two TA1 cladding materials are ground to remove the rust layer and the oxide layer on the surface of the blank, so that the surface completely exposes the fresh metal.

III. Symmetrical composite blank: one of the substrates is selected as the blank, and the four sides of the surface to be composited are fixed by spot welding with a seal width of 60 mm and a thickness of 54 mm. The substrate to be composited in the groove surrounded by the seal Place a circular lamination every 1.5 m, the lamination size is φ30×2.0mm, and fix the lamination on the lower blank to be composited by spot welding; then stack the two non-composite surfaces of the cladding material and place them on Inside the slot. Then, another base material is used as the upper blank, and the laminated piece is spot-welded at the same position as the symmetrical composite surface to be composited, and then the upper blank is to be composited face down, and is placed on the top of the two laminated cladding materials to ensure the upper and lower base. The four sides of the material are flush with the outside of the seal, so that a composite blank to be sealed is formed.

VI, electron beam sealing welding: the assembled composite blank is sent to the vacuum chamber, and then the vacuum chamber is evacuated. When the vacuum chamber vacuum reaches 5×10 ^-2 Pa, the electron beam is used to seal the seal between the substrate and the substrate. The gap is welded, and the welding depths of the upper and lower blanks are both 60 mm, so that a composite blank having a total thickness of 604 mm is obtained.

V, heating: The composite blank is sent to the trolley furnace for heating, the heating temperature is 880 ° C, and the total heating time is 820 min.

VI, rolling and cooling: rolling in a conventional manner, descaling without descaling, rolling descaling for the first pass. The total rolling reduction ratio is 80.1%, the maximum rolling reduction rate is 22%, the final rolling thickness is 120 mm, and the finishing rolling temperature is controlled at about 810 °C. After high-speed steel casting after rolling, the composite board quickly enters ultra-fast cooling for cooling, the cooling rate is 6 ° C / s, and the red return temperature is 630 ° C.

VII. Straightening and cutting the sub-board: After straightening, the upper cooling bed is cooled, and the surface temperature is lowered to 300 ° C. After cutting the head, tail and cutting, the upper and lower single-layer composite panels are separated, and then the single-layer composite panel is straightened, and then the surface of the cladding is polished to obtain a TA1/Q370R composite panel with a finished thickness of 5+55 mm. product.

After testing, the shear strength of TA1/Q370R composite board is about 232MPa, and it still has high bonding performance in large thickness composite board.

Example 4

In this embodiment, an X70 steel grade having a base material thickness of 98 mm, a TA1 industrial pure titanium plate having a thickness of a cladding material of 14 mm, and a titanium steel composite plate for a TA1/X70 pipeline having a thickness of 2+14 mm are selected.

I. Surface treatment: The two composite surfaces of the X70 substrate blank and the two TA1 cladding materials are ground to remove the rust layer and the oxide layer on the surface of the blank, so that the surface completely exposes the fresh metal.

III. Symmetrical composite blank: one of the base materials is selected as the blank, and the four sides of the surface to be composited are fixed by spot welding with a seal width of 40 mm and a thickness of 30 mm. The substrate to be compounded in the groove surrounded by the seal A circular lamination is placed every 0.5 m, the lamination is φ10×1.0 mm, and the lamination is fixed on the lower blank to be composited by spot welding; then the two non-composite surfaces of the cladding are superposed and placed in Inside the slot. Then, another base material is used as the upper blank, and the laminated piece is spot-welded at the same position as the symmetrical composite surface to be composited, and then the upper blank is to be composited face down, and is placed on the top of the two laminated cladding materials to ensure the upper and lower base. The four sides of the material are flush with the outside of the seal, so that a composite blank to be sealed is formed.

VI, electron beam sealing welding: the assembled composite blank is sent to the vacuum chamber, and then the vacuum chamber is evacuated. When the vacuum chamber vacuum reaches 3×10 ^-2 Pa, the electron beam is used to seal the seal between the substrate and the substrate. The gap is welded, and the welding depth of the upper and lower blanks is 40 mm, so that a composite blank having a total thickness of 226 mm is obtained.

V. Heating: The composite blank is sent to a step furnace for heating, the heating temperature is 930 ° C, and the total heating time is 350 min.

VI, rolling and cooling: rolling in a conventional manner, descaling without descaling, rolling descaling for the first pass. The total rolling reduction ratio is 85.8%, the maximum rolling reduction rate is 27%, the final rolling thickness is 32 mm, and the finishing rolling temperature is controlled at about 800 °C. After high-speed steel casting after rolling, the composite plate quickly enters ultra-fast cooling for cooling, the cooling rate is 20 ° C / s, and the red return temperature is 400 ° C.

VII. Straightening and cutting the sub-board: After straightening, the upper cooling bed is cooled, and the surface temperature is lowered to 300 ° C. After cutting the head, tail and cutting, the upper and lower single-layer composite panels are separated, and then the single-layer composite panel is straightened, and then the surface of the cladding is polished to obtain a TA1/X70 pipeline with a finished thickness of 2+14 mm. Titanium steel composite board products.

After testing, the shear strength of TA1/X70 composite board is about 268MPa, which has high bonding performance.

Comparative example 1

The preparation method is the same as that of the second embodiment. The difference is that the laminate is not symmetrically added in the step III, and the intermediate layer nickel foil is added. The specific process is as follows: firstly, two additional dimensions are prepared in accordance with the length and width dimensions of the cladding material, and the thickness is 0.5mm nickel foil, clean the oxide layer on the upper and lower surfaces of the nickel foil to ensure the upper and lower surfaces are clean. One of the substrates is selected as the blank, and the four sides of the surface to be composited are fixed by spot welding with a seal width of 45 mm and a thickness of 21 mm. One nickel is placed on the substrate to be composited in the groove surrounded by the seal. Foil; then, the two clad material non-composite surfaces are superposed, placed on the nickel foil in the trough, and another nickel foil is placed on the two superposed clad materials. Then, another substrate is used as the upper blank, and the upper blank is to be faced with the composite surface facing downward, and is covered on the nickel foil, and at the same time, the four sides of the upper and lower substrates are ensured to be flush with the outer edge of the seal, so that a composite blank to be sealed is formed. After stepwise electron beam sealing, a composite blank having a total thickness of 221 mm is obtained. Then, after heating, rolling and cooling, straightening and cutting the split plate, a TA2/Q345B composite plate with a thickness of 2+20 mm added with an intermediate layer of nickel foil can be obtained, and the shear strength is 243 MPa after testing, as shown in Table 1. Shown.

Comparative example 2

The preparation method is the same as that of the second embodiment. The difference is that the straight composite is used in the symmetric combination of the blanks in the step III, and the TA2/Q345B composite plate with a thickness of 2+20 mm is prepared without adding a laminate or an intermediate layer. After testing, the titanium steel composite plate TA2/Q345B with direct blanking has a shear strength of only 178 MPa, as shown in Table 1.

It can be seen from the comparison of the data in Table 1 that by adding the laminate, the titanium steel composite plate with high bonding property can be prepared, and the shear strength is equivalent to the shear strength of the added intermediate layer nickel foil, and far exceeds the titanium steel prepared by the direct preform. Shear strength of the composite panel. However, by adding the laminated blank, the process is simple and the cost is low; while the intermediate layer of nickel foil is added, the nickel foil is expensive, and the operation of cleaning the upper and lower surfaces of the nickel foil is cumbersome and costly.

Table 1 Comparison of shear strength of titanium steel composite sheets prepared by adding laminated sheets, adding intermediate layer nickel foil and directly forming blanks

Other than the above-described embodiments, the present invention may have other embodiments. Any technical solution formed by equivalent replacement or equivalent transformation falls within the protection scope of the present invention.

Claims

A method for preparing a titanium steel composite panel, comprising the steps of:

(1) subjecting the surface to be composited of the substrate and the covering blank to a surface treatment;

(2) coating the non-composite surface of the cladding material obtained in the step (1) with a release agent, and drying;

(3) Selecting a piece of substrate obtained in step (1) as a blank, and the four sides of the blank to be composited surface are fixed by spot welding, enclosing a groove, and spot welding on the composite surface of the blank in the groove a plurality of laminations, then placing the non-composite surface of the two superposed materials obtained in the step (2) in the groove, and then using the other substrate obtained in the step (1) as the upper blank, the upper blank to be composited Spot welding fixed a plurality of laminations, and the upper blank to be composited facing down on the two covering materials, ensuring that the outer peripheral edges of the upper and lower blanks are flush with the outer edge of the sealing strip to form a symmetrical composite blank;

(4) welding the symmetric composite blank obtained in the step (3) under a vacuum environment;

(5) heating the symmetric composite blank obtained in the step (4);

(6) subjecting the symmetric composite blank obtained in the step (5) to hot rolling and cooling;

(7) Straightening the symmetrical composite blank obtained in the step (6) and cutting the split plate to obtain a titanium steel composite plate.
The preparation method according to claim 1, wherein the substrate in the step (1) is carbon steel or low-alloy high-strength steel, the covering material is industrial pure titanium; and the surface treatment method is abrasive belt. Grinding or milling machine processing.
The preparation method according to claim 1, wherein the main component of the release agent in the step (2) is MgO powder.
The preparation method according to claim 1, wherein the composition of the seal in step (3) is consistent with the substrate, the width of the seal is 30 to 60 mm, and the height of the seal is two stacks. The sum of the thickness of the clad material and the thickness of the two laminate sheets.
The preparation method according to claim 1, wherein the composition of the laminate in step (3) is identical to the substrate, the laminate is a circular laminate, and the laminate has a diameter of 10 ～30mm, the thickness is 0.5～2mm; the laminations on the under-composite composite surface and the upper blank to be composited are placed in the same manner, and one lamination is placed every 0.5~1.5m.
The preparation method according to claim 1, wherein in step (4), the blank and the blank of the symmetric composite blank are welded to the gaps of the seal, the seal and the seal by vacuum electron beam welding, and the welding depth is uniform. It is 30 to 60 mm, and the degree of vacuum during welding is less than 5 × 10 -2 Pa.
The preparation method according to claim 1, wherein the heating temperature in the step (5) is 850 to 930 ° C, and the heating time is controlled in accordance with the thickness of the composite blank by 10 to 30 min/cm.
The preparation method according to claim 1, wherein the finishing rolling temperature of the hot rolling in the step (6) is ≥700 ° C, and the total rolling reduction ratio is ≥80%, wherein the single pass maximum reduction ratio ≥20%.
The preparation method according to claim 1, wherein the cooling in the step (6) is rapid cooling or natural cooling of the air; the rapid cooling is performed at a speed of 2 to 20 ° C / s, and the reddening temperature is controlled at 400～700°C; when the total thickness of rolling is >16mm, rapid cooling is adopted; when the total thickness of rolling is ≤16mm, rapid cooling or natural cooling of air is adopted.
The preparation method according to claim 1, wherein the titanium steel composite plate in the step (7) has a total thickness of 6 to 60 mm, wherein the thickness of the cladding material is 0.5 to 5 mm.