CN116604899A

CN116604899A - Single-sided stainless steel composite board and preparation method thereof

Info

Publication number: CN116604899A
Application number: CN202310341388.0A
Authority: CN
Inventors: 镇凡; 曲锦波; 邵春娟; 杨浩
Original assignee: Jiangsu Shagang Group Co Ltd; Zhangjiagang Hongchang Steel Plate Co Ltd; Jiangsu Shagang Iron and Steel Research Institute Co Ltd
Current assignee: Jiangsu Shagang Group Co Ltd; Zhangjiagang Hongchang Steel Plate Co Ltd; Jiangsu Shagang Iron and Steel Research Institute Co Ltd
Priority date: 2023-04-03
Filing date: 2023-04-03
Publication date: 2023-08-18

Abstract

The invention discloses a stainless steel composite board and a preparation method thereof. Both sides of the composite board in the Y direction are positioned in the upper surface of the base layer. The preparation method comprises the following steps: preparing two carbon steel billets as two base materials, wherein the X-direction dimension is L1, and the Y-direction dimension is W1; preparing three stainless steel billets as a composite material A, a composite material B and a composite material C respectively; the X-direction dimensions of the three are L2, the thickness of the three are T2, and the Y-direction dimensions of the three are W21, W22 and W23 respectively; assembling the base materials according to the base materials, the composite material A, the composite material B, the composite material C and the base materials, and welding the sealing strips with the two base materials, wherein the sealing strips are enclosed on four sides of the middle layer; and vacuumizing, sealing, heating, rolling, cooling, separating and straightening the composite blank base blank to obtain the stainless steel composite plate. Therefore, the stainless steel composite board in use avoids the existing dissimilar welding problem, and has strong firmness, low production difficulty, low cost and high construction efficiency in use.

Description

Single-sided stainless steel composite board and preparation method thereof

Technical Field

The invention relates to a single-sided stainless steel composite board and a preparation method thereof, belonging to the technical field of steel material preparation.

Background

In recent years, with the continuous improvement of requirements on safety, long service life and the like of a steel bridge, the rust prevention and corrosion prevention problems of a steel bridge structure are more and more prominent, and if a layer of corrosion-resistant protective material is coated on the surface of bridge steel, the corrosion-resistant protective material is used for replacing a single bridge steel plate, so that the long-term corrosion prevention target which cannot be achieved by a spraying process can be realized. Accordingly, stainless steel composite panels have been developed.

The stainless steel composite board is a composite board which takes stainless steel as a composite layer and carbon steel or low alloy steel as a base layer, has the corrosion resistance of the composite layer and good mechanical properties of the base layer, can save resources and reduce cost on the premise of not reducing the using effect (mechanical strength, corrosion resistance and the like), realizes perfect combination of low cost and high performance, and has good economic and social benefits.

The existing stainless steel composite board for the bridge structure is required to be in butt joint with a steel plate for the bridge structure in the processing and using process of a downstream structural factory.

At the butt joint position, the base layer of the stainless steel composite board and the steel plate for the bridge structure belong to the same material, and the welding strength can be ensured. However, the stainless steel composite plate has the advantages that the stainless steel composite layer and the steel plate for the bridge structure are made of different materials, the welding difficulty is high, the firmness is poor, and the safety of the whole structural member is influenced to a certain extent; in addition, in order to avoid steps (height difference) between the edge of the stainless steel cladding layer and the steel plate for the bridge structure, a stainless steel plate is additionally added for transition, so that not only is the additional material cost increased, but also the added stainless steel plate is welded with the cladding layer of the stainless steel composite plate and the steel plate for the bridge structure, the welding workload is greatly increased, and the construction efficiency is influenced.

Disclosure of Invention

The invention aims to solve the problem of dissimilar welding of the existing stainless steel composite plate and provides a single-sided stainless steel composite plate and a preparation method thereof.

In order to achieve the above object, an embodiment of the present invention provides a single-sided stainless steel composite board. The composite board is formed by compounding a carbon steel base layer at the lower part and a stainless steel composite layer at the upper part, two side edges of the composite layer in the X direction are respectively flush with two side edges of the base layer in the X direction, and two side edges of the composite layer in the Y direction are both positioned in the upper surface of the base layer.

As a preferred embodiment, one or both sides of the clad layer in the Y direction are provided as oblique sides forming an obtuse angle with the upper surface of the clad layer.

As a preferred embodiment, the two sides of the cladding layer in the Y direction have the same angle with the upper surface of the cladding layer.

As a preferred embodiment, the total thickness of the composite board is 15-39 mm, the thickness of the base layer is 12-36 mm, and the thickness of the multiple layers is 3mm.

As a preferred embodiment, the unevenness of the composite plate is less than or equal to 2mm/m.

In order to achieve the above object, an embodiment of the present invention provides a method for manufacturing a single-sided stainless steel composite board. The preparation method comprises the following steps:

Preparing two carbon steel billets as two base materials, wherein the X-direction dimension is L1, and the Y-direction dimension is W1;

preparing three stainless steel billets as a composite material A, a composite material B and a composite material C respectively; the X-direction dimensions of the three are L2, the thickness of the three are T2, and the Y-direction dimensions of the three are W21, W22 and W23 respectively;

assembling according to the mode that one base material is used as an upper layer, the other base material is used as a lower layer, the composite material A, the composite material B and the composite material C are sequentially arranged side by side in the Y direction, are used as an intermediate layer, and are surrounded on four sides of the intermediate layer by seals and are welded with the two base materials together, so as to form a composite blank base blank; wherein, the non-to-be-compounded surfaces of the composite material A, the composite material B and the composite material C in the thickness direction and the connected side edges of the two adjacent composite materials are coated with isolating agents;

and vacuumizing, sealing, heating, rolling, cooling, separating and straightening the composite blank base blank to obtain the stainless steel composite plate.

As a preferred embodiment, the connected sides of the composite material A and the composite material B are oblique sides with the width V1, and in the composite blank base blank, the oblique sides of the composite material A and the composite material B are parallel and opposite.

As a preferred embodiment, the connected sides of the composite material B and the composite material C are oblique sides with a width V2, and in the composite blank base blank, the oblique sides of the composite material B and the composite material C which are connected are parallel and opposite.

As a preferred embodiment, both bevel edges of the composite material B form an obtuse angle with the non-composite surface of the composite material B.

As a preferred embodiment, l1=l2+90 to 150mm, w1=w21+w22+w23-v1-v2+90 to 150mm.

As a preferred embodiment, the step of "vacuuming, sealing, heating, rolling, cooling, separating and straightening the composite blank base blank" specifically includes:

vacuumizing and sealing the composite blank base blank to obtain a composite blank;

heating the obtained composite blank, wherein the soaking temperature is 1150-1220 ℃, the total heating time is more than or equal to 1.2×tmin/mm, t is the thickness of the composite blank, and the heat preservation time of a soaking section is 30-50 min;

the method comprises the steps of adopting two-stage control rolling of rough rolling and finish rolling, wherein in the rough rolling stage, the initial rolling temperature is less than or equal to 1050 ℃, the final rolling temperature is more than or equal to 980 ℃, transverse rolling is performed firstly, then longitudinal rolling is performed, at least one pass of rolling reduction is more than or equal to 35mm in the longitudinal rolling process, the total rolling reduction of rough rolling is 40-60%, and the rough rolling stage is finished when the thickness of an intermediate blank is 2.5-3.5 times of the target thickness of a large plate of the composite plate; then, when the temperature is reached, watering and cooling are carried out during the period, and when the surface temperature of the intermediate billet is reduced to below 860 ℃, the finish rolling stage is started; the finishing temperature in the finish rolling stage is more than or equal to 780 ℃, and the total rolling reduction of the finish rolling is 55-75%, so that the composite board large plate is obtained.

five-stage heating of preheating, one heating, two heating, three heating and soaking is adopted for the obtained composite blank, the preheating temperature is less than or equal to 850 ℃, the retention time is (0.45-0.55) t min/mm, the heating temperature is 1030-1090 ℃, the retention time is (0.35-0.45) t min/mm, the two heating temperatures are 1100-1160 ℃, the retention time is (0.25-0.35) t min/mm, the three heating temperatures are 1140-1180 ℃, the retention time is (0.15-0.25) t min/mm, the soaking temperature is 1170-1210 ℃, the retention time is (0.10-0.20) t min/mm, and t is the thickness of the composite blank;

two-stage controlled rolling of rough rolling and finish rolling is adopted, longitudinal rolling is adopted in the 1 st pass, and rolling reduction is more than or equal to 46mm; the 2 nd pass starts to adopt transverse rolling until the n th pass rolls the composite blank to the target width of the final composite board large plate, and the rolling reduction of the 2 nd pass is more than or equal to 25mm; the n+1th pass adopts longitudinal rolling, and the rolling reduction of the n+1th pass is more than or equal to 30mm; in the whole rough rolling stage, the rolling temperature of the 1 st pass is more than or equal to 1060 ℃, the initial rolling temperature of the rest passes is less than or equal to 1050 ℃, and the final rolling temperature is more than or equal to 1000 ℃; finishing the rough rolling stage when the thickness of the intermediate blank is 2.5-3.5 times of the target thickness of the large composite board, carrying out water cooling during the temperature waiting, starting the finish rolling stage when the surface temperature of the intermediate blank is reduced to below 840 ℃, and finishing the rolling stage at the initial rolling temperature of 810-840 ℃ and the finishing temperature of 780-810 ℃.

after rolling is finished, the rolled piece plate enters an ultra-fast cooling system for intermittent cooling: the ultra-fast cooling system is provided with 24 groups of cooling headers which are arranged along a roller way at intervals of 1M, the cooling distance of each group of cooling headers is 1M, when a rolled piece plate passes through the ultra-fast cooling system, the opening and closing states of all 24 groups of cooling headers are controlled in a mode that N groups of cooling headers are opened every time and then M groups of cooling headers are not opened, the cooling water pressure is 0.15-0.30 MPa, the cooling speed is 3-15 ℃ per unit time, and the final cooling temperature is 380-590 ℃; wherein N takes on the value of 2, 3 or 4, and M takes on the value of 2, 3 or 4.

Compared with the prior art, the invention has the beneficial effects that: the middle part of the stainless steel composite board is a composite structure formed by carbon steel and stainless steel, so that the composite board has corrosion resistance of a composite layer as the existing composite board, and has good mechanical properties of a base layer; the two ends of the stainless steel composite board are pure carbon steel plates, the stainless steel composite board and the composite structure are directly integrally formed, and the carbon steel plates at the two ends can be directly used in engineering to save welding, so that the stainless steel composite board avoids the existing dissimilar welding problem in use, and has strong firmness, low production difficulty, low cost and high construction efficiency in use.

Drawings

In the various illustrations of the invention, certain dimensions of structures or portions are exaggerated relative to other structures or portions for clarity of illustration and description, and thus serve only to illustrate the basic structure of the inventive subject matter.

FIG. 1 is a schematic cross-sectional view of a single-sided stainless steel composite panel in an embodiment of the invention;

FIG. 2 is a flow chart of a method of manufacturing a stainless steel composite plate in an embodiment of the invention;

FIG. 3 is a schematic cross-sectional view of a substrate and composite in an embodiment of the invention;

FIG. 4 is a schematic cross-sectional view of a composite blank in an embodiment of the invention;

fig. 5 is a schematic cross-sectional view of a stainless steel composite panel obtained by the manufacturing method in one embodiment of the present invention.

Detailed Description

An embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Referring to fig. 1, an embodiment of the present invention provides a stainless steel composite plate, which is formed by combining a lower carbon steel base layer 100 and an upper stainless steel clad layer 200.

A pair of side edges 201, 202 of the composite layer are flush with a corresponding pair of side edges of the base layer 100; while the other pair of sides 203, 204 of the overlay are not flush with the corresponding other pair of sides of the base layer 100, but are located inwardly of the upper surface of the base layer 100. That is, the dimensions of the base layer 100 and the composite layer 200 are not uniform in one of the longitudinal direction (i.e., length direction) and the transverse direction (i.e., width direction) of the composite plate. Specifically, for example, the pair of side edges 203, 204 may be opposite sides of the composite panel in the transverse direction or opposite sides of the composite panel in the longitudinal direction.

Thus, the stainless steel composite board of the embodiment of the invention has the composite structure formed by carbon steel and stainless steel in the middle part, can be like the existing composite board, has the corrosion resistance of multiple layers and has good mechanical property of a base layer; the two ends of the stainless steel composite board are pure carbon steel plates, the stainless steel composite board and the composite structure are directly integrally formed, and the carbon steel plates at the two ends can be directly used in engineering to save welding, so that the stainless steel composite board avoids the existing dissimilar welding problem in use, and has strong firmness, low production difficulty, low cost and high construction efficiency in use.

Preferably, the sides 203 and 204 are disposed at an obtuse angled edge to the upper surface of the cladding 200, such that there is no right angle step between the angled edge and the carbon steel substrate 100 that would affect the layout of the bridge's overall structure. Further, the angle between the side 203 and the upper surface of the composite layer 200, and the angle between the side 204 and the upper surface of the composite layer 200 may be the same, or may be different. In addition, in a variant embodiment, it is also possible to provide one of the sides 203 and 204 as a beveled edge and the other as a right-angle edge.

Preferably, the total thickness of the composite board is 15-39 mm, the thickness of the base layer is 12-36 mm, and the thickness of the composite layer is 3mm.

Next, referring to fig. 2, an embodiment of the present invention further provides a method for manufacturing a stainless steel composite plate. The preparation method comprises the steps of preparing a steel billet, coating a separating agent, assembling the steel billet, vacuumizing, sealing, heating, rolling, cooling, separating plates, straightening and the like. Specifically comprising:

Thus, a single-sided stainless steel composite board can be prepared, as shown in figure 1, the middle part of the stainless steel composite board is a composite structure formed by carbon steel and stainless steel, and the composite board has corrosion resistance of a composite layer and good mechanical property of a base layer as the existing composite board; the two ends of the stainless steel composite board are pure carbon steel plates, the stainless steel composite board and the composite structure are directly integrally formed, and the carbon steel plates at the two ends can be directly used in engineering to save welding, so that the stainless steel composite board avoids the existing dissimilar welding problem in use, and has strong firmness, low production difficulty, low cost and high construction efficiency in use.

Further preferred embodiments of the preparation process are described below in terms of the individual steps.

< step of preparing billet >

Referring to fig. 3, this step is basically a step of preparing a base material and a composite material.

The method specifically comprises the following steps: two carbon steel billets were prepared as two substrates, such as substrate 1 and substrate 2 in fig. 3, having an X-direction dimension L1 and a Y-direction dimension W1. Wherein one of the X direction and the Y direction is a longitudinal direction (i.e. the length direction of the substrate) and the other is a transverse direction (i.e. the width direction of the substrate).

In addition, the thicknesses of the base material 1 and the base material 2 can be set to be the same or different, and if the thicknesses are set to be different, the stainless steel composite plates with different thickness specifications can be correspondingly prepared.

The method specifically comprises the following steps: preparing three stainless steel billets as a composite material A, a composite material B and a composite material C respectively, wherein the composite material A is marked as a composite material 3 in the figure, the composite material B is marked as a composite material 5 in the figure, and the composite material C is marked as a composite material 4 in the figure, for example, as shown in fig. 3; the three composite materials have the X-direction dimension of L2, the thickness of T2 and the Y-direction dimension of W21, W22 and W23 respectively.

That is, the dimensions of the composite 3, the composite 5, and the composite 4 in the X direction are the same, and the thicknesses are also the same; the dimensions of the composite material 3, the composite material 5, and the composite material 4 in the Y direction may be all the same (i.e., w21=w23=w22), or may be the same (i.e., w21=w23=w22, or w21=w22=w23), or may be different (i.e., w21=w22=w23).

As a further preferred embodiment, one side 33/in the Y direction of the composite material 3 is provided as the oblique side of the width V1, and correspondingly one side 53/in the Y direction of the composite material 5 is also provided as the oblique side of the width V1. Here, the sloping sides 33/, 53/i.e. the side where the composite 3 and the composite 5 meet each other in the assembling step, are shown in fig. 4. Thus, the composite panels finally produced with composite 3, composite 5 can be provided with beveled cladding (e.g., the stainless steel composite panel labeled as cladding 3 in fig. 5, and the stainless steel composite panel labeled as cladding 5).

Further, one side 43/of the composite material 4 in the Y direction is provided as the oblique side of the width V2, and the other side 54/of the composite material 5 in the Y direction is provided as the oblique side of the width V2. Here, the oblique sides 43/, 54/i.e. the side where the composite 4 and the composite 5 meet each other in the assembling step, are shown in fig. 4. Thus, the composite board finally produced with the composite material 4 (such as the stainless steel composite board labeled as the composite layer 4 in fig. 5) can be provided with a bevel composite layer; of course, the combination of the bevel edge 53/and the bevel edge 54/of the composite material 5 may enable the composite board (e.g. the stainless steel composite board labeled as the composite layer 5 in fig. 5) to be finally manufactured from the composite material 5, wherein both sides of the composite layer 5 in the Y direction are bevel edges.

More preferably, the bevel 53/54/of the composite 5 are at an obtuse angle to the non-composite surface 51/of the composite 5. Reference herein to a "non-surface to be compounded" refers to a surface that does not require interfacial bonding with a substrate. In addition, in view of the presence of oblique edges, the non-to-be-compounded surface 51 is of dimension W23-V1-V2 in the Y direction as shown in FIG. 3. Correspondingly, the other surface 52 of the composite 5/the surface constituting the composite 5 which subsequently needs to be interface-bonded with the substrate 1 is hereinafter referred to as the surface 52/.

The surface 32 of the composite material 3 is a larger surface with a dimension W21 in the Y direction, and the surface 32 is the surface 32/-to-be-compounded of the composite material 3 which is required to be subjected to interface bonding with the substrate 2 in the subsequent process; while the surface 31/is the smaller surface of dimension W21-V1 in the Y direction, the surface 31/constituting the composite 3 is the surface that subsequently does not need to be interface bonded with the substrate, hereinafter referred to as non-composite surface 31/.

Similarly, the surface 42/of the composite material 4 is the surface 42/, which has a dimension W22 in the Y direction, and the surface 41/is the surface 41/, which has a dimension W22-V2 in the Y direction.

As a further preferred embodiment, regarding the dimensional relationship of composite 3, composite 5, composite 4, and base 1, base 2, l1=l2+90 to 150mm, w1=w21+w22+w23-v1-v2+90 to 150mm.

In a further preferred embodiment, the step specifically further comprises: and (3) polishing one surface of each base material and the surface to be compounded of each composite material to remove surface oxide skin and expose metallic luster. Specifically, referring to fig. 3, for example, for the substrate 1 and the substrate 2, either one of the two surfaces in the thickness direction may be selected for polishing treatment, such as the surface 1/-of the substrate 1, the surface 2/-of the substrate 2, specifically polishing may be performed by using a grinder, a belt sander, or a milling machine; for the composite material 3, the composite material 5 and the composite material 4, polishing treatment is performed on the respective surfaces to be compounded, such as the surface 32/, the surface 52/, and the surface 42/, of the substrate 3, the substrate 5, and the substrate 4, and specifically, polishing may be performed by using a wire wheel. Therefore, the interface bonding strength of the finally obtained stainless steel composite board is improved through polishing.

Preferably, the two composite materials are austenitic stainless steel. The chemical components of the paint comprise the following components in percentage by mass: c is less than or equal to 0.15%, si is less than or equal to 1.00%, mn is less than or equal to 2.00%, P is less than or equal to 0.045%, S is less than or equal to 0.030%, ni:6.0 to 22.0 percent, cr:16.0 to 26.0 percent, mo is less than or equal to 3.0 percent, and the balance is Fe and unavoidable impurities. The stainless steel billet with the chemical composition can further ensure the performance of the composite board, especially the corrosion resistance of the composite board under the condition of the technical effects, for example, the composite board obtained by the method (namely obtained by rolling the composite board) is boiled in sulfuric acid-copper sulfate solution for 20 hours, and after 180 DEG bending, no intergranular corrosion cracks exist.

The chemical components of the two composite materials may be the same or different, and only one of the two composite materials may or may not use the chemical component provided by the preferred scheme.

As a preferred scheme, the chemical components of the base material are as follows by mass percent: c:0.03 to 0.16 percent, si:0.11 to 0.29 percent, mn:1.31 to 1.54 percent, P is less than or equal to 0.018 percent, S is less than or equal to 0.0030 percent, cr: 0.06-0.29%, nb: 0.011-0.034%, ti: 0.011-0.019%, al:0.030 to 0.040 percent, and the balance of Fe and unavoidable impurities.

Here, the chemical components of the two substrates may be the same or different, and only one of the two substrates may or may not use the chemical component provided by the above preferred embodiment.

< step of applying Release agent >

The method specifically comprises the following steps: and coating a release agent on the non-to-be-compounded surfaces of the three composite materials, and coating the release agent on the connected side edges of the two adjacent composite materials in the subsequent assembly step.

For example, referring to fig. 3, the oblique side 33 of the composite material 3 and the oblique side 53 of the composite material 5 are used as the joining side edges of the two in the subsequent assembling step, and the oblique side 43 of the composite material 4 and the oblique side 54 of the composite material 5 are used as the joining side edges of the two in the subsequent assembling step. Thus, in this release agent application step, release agents are applied to the non-to-be-compounded surface 31/and the bevel edge 33/, the non-to-be-compounded surface 51/, the bevel edge 53/and the bevel edge 54/, and the non-to-be-compounded surface 41/and the bevel edge 43/, respectively, of the composite material 3, the composite material 5.

Therefore, unexpected compounding of the non-to-be-compounded surfaces and adjacent composite materials can be avoided in the follow-up heating, rolling and other steps through the release agent, and finally, the surfaces which do not need to be compounded are separated from each other.

Regarding the chemical composition of the release agent, the first embodiment is: a coating liquid comprising silicon oxide and magnesium oxide, wherein the mass ratio of silicon oxide to magnesium oxide is 3:1. The preparation method of the release agent comprises the following steps: the method comprises the following steps of mixing release agent powder, binder powder and water according to a mass ratio of 27:3:70, mixing to obtain the fluid release agent coating liquid. Wherein the isolating agent powder is silicon oxide and magnesium oxide, and the mass ratio is 3:1. The binder powder is polyvinyl alcohol and thermosetting phenolic resin, and the mass ratio is 1: 1.

The isolating agent of the embodiment can achieve good isolating effectAnd the separation of the two subsequent composite board small plates is ensured. With the release agent, the coating amount of each surface was 20ymg/m ² I.e. the release agent 20ymg is coated on each square meter surface, wherein y is the ratio of the thickness of the composite billet produced in the composite billet preparation step to the thickness of the large composite plate formed by subsequent rolling, which is also called the composite billet rolling compression ratio. After finishing coating the release agent and before the subsequent assembly step, the composite material coated with the release agent is placed in a trolley furnace for heating and drying, wherein the drying temperature is 340-360 ℃ and the drying time is 35-45 min.

Regarding the chemical composition of the release agent, a second embodiment is: the components are 25 to 35 percent of silicon nitride, 5 to 10 percent of thermosetting amino resin and 55 to 70 percent of water according to the weight ratio. Compared with the existing isolating agent and even compared with the first embodiment of the isolating agent, the isolating agent of the embodiment not only can achieve good isolating effect and ensure the subsequent separation of two composite board small plates, but also has strong chemical stability, high temperature resistance and thermal shock resistance of the active ingredient silicon nitride, and the thermosetting amino resin serving as the binder can be cured at low temperature, has no toxicity and can achieve stronger bonding effect with little consumption, thus the isolating agent is low in cost as a whole, simple to operate and good in isolating and attaching effects.

There is provided a preferred method of preparing the release agent of the second embodiment, comprising: firstly, placing 5-10% of silicon nitride (in percentage by weight) into a container such as a beaker, and then pouring 15-25% of water for stirring; after the silicon nitride has no granular feel and no bubble, pouring 2-3% of thermosetting amino resin, and continuing stirring; when the mixture is in a viscous state, continuously pouring the residual silicon nitride and water, stirring for 3-5 min, and pouring the residual thermosetting amino resin; and (5) stirring to be sticky, and preparing the release agent.

For the release agent of the second embodiment, each surface is painted with a thickness of 0.2 to 0.5 mm; after finishing coating the release agent and before the subsequent assembly step, heating and drying the composite material coated with the release agent at the temperature of 100-250 ℃ for 20-40 min.

In fig. 4, the thickness of the release agent coating layer is very small for each steel sheet, and therefore the release agent coating layer is not illustrated in the drawing.

< step of assembling >

Specifically, the method comprises the following steps: and assembling according to the mode that one base material is taken as an upper layer, the other base material is taken as a lower layer, the composite material 3, the composite material 5 and the composite material 4 are sequentially arranged side by side in the Y direction, and the base material is taken as an intermediate layer, and seals are wrapped on four sides of the intermediate layer and welded with the two base materials together to form a composite blank base blank.

As can be seen in connection with fig. 4, the composite green body formed is:

1) A substrate 1 as an upper layer and a substrate 2 as a lower layer;

2) The composite material 3, the composite material 5 and the composite material 4 are sequentially arranged side by side in the Y direction to form an intermediate layer together, namely, the three are tiled between the base material 1 and the composite material 2;

3) The seals 6 are enclosed on four sides of the middle layer; specifically, two sides of the middle layer in the Y direction are respectively one side of the composite material 3 and one side of the composite material 4, one side of the middle layer in the X direction is respectively formed by one side of the composite material 3, one side of the composite material 5 and one side of the composite material 4, and the other side of the middle layer in the X direction is also respectively formed by the other side of the composite material 3, the other side of the composite material 5 and the other side of the composite material 4; four seals 6 surround four sides of the middle layer and are approximately surrounded to form four frames;

4) The upper edge of the seal 6 is welded to the lower surface of the base material 1, and the lower edge of the seal 6 is welded to the upper surface of the base material 2.

While the basic structure of the composite green body has been described above, it will be appreciated that the composite green body may be formed in a number of ways, such as: firstly stacking the base materials 2, the composite materials 3, the composite materials 5, the composite materials 4 and the base materials 1 in sequence, then wrapping four seals 6 around the composite materials 3, the composite materials 5 and the composite materials 4, and finally welding the upper edge and the lower edge of the seals 6 with the base materials 1 and 2; or, the seal 6 and the base material 1 may be welded first, so that a four-sided frame surrounded by the seal 6 is formed on the surface of the base material 1, then the base material 2, the composite material 3+composite material 5+composite material 4 and the base material 1 are stacked in sequence, the four-sided frame on the surface of the base material 1 is buckled around the composite material 3+composite material 5+composite material 4 in the stacking, and finally the lower edge of the seal 6 and the base material 2 are welded. The present invention is not limited to this, as long as the above-described composite green body can be formed, by way of example only.

Thus, according to the preparation method of the invention, the preparation of the steel billet, the coating of the isolating agent and the assembly are carried out, and the obtained composite billet base blank is vacuumized, sealed, heated, rolled, cooled, split and straightened, so that the stainless steel composite plate finished product shown in figure 5 can be obtained, the dissimilar welding problem existing in the prior art can be solved, and the preparation method has the advantages of strong use firmness, low production difficulty, low cost and high construction efficiency compared with the existing composite plate.

In a further preferred embodiment, in the case where the base material is provided with a bevel edge as described above, in the composite blank obtained in this step, the bevel edges of two adjacent composite materials are parallel-opposed, for example, the bevel edge 33 of the composite material 3 is parallel-opposed to the bevel edge 53 of the composite material 5, and the bevel edge 43 of the composite material 4 is parallel-opposed to the bevel edge 54 of the composite material 5.

In a further preferred embodiment, the seal 6 is selected from a steel billet, and specifically, for example, the same steel type as the base material 1 and the base material 2.

Further, regarding the dimensions of the four seals 6, the width of the seal 6 (i.e., the span in the thickness direction of the composite blank base) is from T2-2mm to T2, that is, the width is equal to the thickness T2 of the composite material or is within about 2mm less than the thickness T2 of the composite material; the thickness of the seal 6 is 12-15 mm.

At the two side edges of the composite blank in the Y direction, the length of the seal 6 is L2-2 mm-L2, namely, the length is equal to the dimension L2 of the composite material in the X direction or is less than about 2mm in the X direction; and the lengths of the seals 6 at the two side edges in the X direction of the composite blank base are W21+W22+W23-V1-V2-2 mm-W21+W22+W23-V1-V2. I.e. the length is equal to or less than about 2mm of the Y-direction dimension of the corresponding side of the intermediate layer of composite 3+ composite 5+ composite 4.

The forming mode of each seal strip can be directly cut out on a steel plate according to the thickness without welding, or can be formed by splicing a plurality of seal strips with different lengths through welding.

In a further preferred embodiment, the lower surface of the substrate 1 on the upper layer is the surface 1/, which is subjected to polishing treatment as described above, so that the surface 1/and the surface 42/which is contacted with the surface are subjected to polishing treatment, and the bonding quality of the composite interface is good; similarly, the upper surface of the lower substrate 2 is the surface 2/, which is subjected to polishing treatment as described above, so that the surface 2/and the surface 32/which is contacted with the surface are subjected to polishing treatment, and the bonding quality of the composite interface is good.

In a further preferred embodiment, in this step, the upper edge of the seal 6 is welded to the lower surface of the substrate 1, and the lower edge of the seal 6 is welded to the upper surface of the substrate 2 by gas shielded welding. Preferably, the welding speed in gas shielded welding is 300-360 mm/min, and the inter-channel temperature is controlled at 135-175 ℃. Before the gas shielded welding, the substrate 1 and the substrate 2 are preferably preheated and baked by a flame gun, respectively, at a baking temperature of 100 to 200 ℃.

In a further preferred embodiment, the intermediate layer of composite 3, composite 5 and composite 4 is placed centrally with respect to the substrate. In this regard, the dimensional relationships between the composite materials 3, 5, 4 and the substrates 1, 2 are described as l1=l2+90 to 150mm, w1=w21+w22+w23-v1-v2+90 to 150mm, and when assembled, the distances from the two sides of the intermediate layer in the X direction to the corresponding two sides of the substrates are equal, for example, half of L1-L2, and the distances from the two sides of the intermediate layer in the Y direction to the corresponding two sides of the substrates are equal, for example, half of w1- (w21+w22+w23-v1-V2).

In a further preferred embodiment, the four sides of the composite blank base have grooves formed between the two substrates, outside the seal 6. The method specifically comprises the following steps: processing a circular through hole on a seal 6 at one side edge of the composite blank base blank, and sealing and welding a circular tube with the same diameter as the through hole in the through hole; and overlaying the grooves on the four sides of the composite blank base blank.

Wherein, the overlaying can be specifically submerged arc overlaying. It will be appreciated that, outside the four-sided frame formed by the seal 6, a filling layer in the shape of a four-sided frame is formed by the build-up welding in this step, see fig. 4, in which the filling layer formed by the build-up welding is denoted by 7.

As a preferred mode, before surfacing welding, the flux is baked for 2 hours at 350 ℃ and then is kept at 150 ℃ for 1 hour; in the welding process, the temperature between control channels is 135-165 ℃, the welding current is 570-630A, the welding voltage is 28-32V, and the welding speed is 420-480 mm/min. Therefore, the submerged arc surfacing technology combines the sealing strip surrounding and gas shielded welding to jointly realize the stable connection of four billets, ensures the connection strength, avoids cracking abnormality in the subsequent composite billet rolling step, and further improves the interface bonding effect of the final composite plate.

In addition, in the process of surfacing welding, before each welding construction, welding bead attachments need to be cleaned, and welding beads are kept clean; and after the surfacing welding is finished, covering with heat-insulating cotton to insulate heat.

< step of evacuating >

In the vacuumizing step, an air suction port of the vacuum pump is in butt joint with a round pipe, and the round pipe is communicated with a space (such as a surface gap between a composite material and a base material, an end surface gap between the composite material and a seal strip and the like) in the composite blank base blank so as to discharge air in the space until the vacuum degree is less than or equal to 10 ^-1 Pa, and then maintaining the pressure for more than 4 hours. Therefore, air in the space can be avoided, surface oxidation at the composite interface is caused in the subsequent rolling of the composite blank, and the bonding quality of the composite interface is ensured.

< sealing step >

In the sealing step, the round tube is sealed, and thus, a composite blank is prepared. The sealing mode can be implemented in the existing feasible mode in the steel field, for example, a seamless steel pipe is heated by a flame gun and clamped flat, so that sealing is realized.

The above processes of preparing the steel billet, coating the parting agent, assembling, vacuumizing and sealing can be summarized as a composite billet preparation stage, and the specific embodiment of the composite billet preparation stage is described in detail above. The heating, rolling and cooling processes can be summarized as a clad-stock rolling stage, and various preferred embodiments of the clad-stock rolling stage are provided herein, and are described separately below.

< first embodiment >

In this embodiment, the composite billet rolling stage includes the following steps.

And a heating step: heating the obtained composite blank, wherein the soaking temperature is 1150-1220 ℃, the total heating time is more than or equal to 1.2 Xt min/mm, t is the thickness of the composite blank, and the heat preservation time of a soaking section is 30-50 min;

and (3) rolling: two-stage controlled rolling by rough rolling and finish rolling, wherein in the rough rolling stage, the initial rolling temperature is adopted

The final rolling temperature is equal to or less than 1050 ℃, the transverse rolling is carried out firstly, then the longitudinal rolling is carried out, the reduction of at least one pass is equal to or more than 35mm during the longitudinal rolling, the total reduction of rough rolling is 40-60%, and the rough rolling stage is finished when the thickness of the intermediate billet is 2.5-3.5 times of the target thickness of the large composite plate; then, when the temperature is reached, watering and cooling are carried out during the period, and when the surface temperature of the intermediate billet is reduced to below 860 ℃, the finish rolling stage is started; the finishing temperature in the finish rolling stage is more than or equal to 780 ℃, and the total rolling reduction of the finish rolling is 55-75%;

and (3) a cooling step: after exiting the rolling mill, the rolled piece plate enters an ultra-fast cooling system for cooling, the cooling temperature is more than or equal to 730 ℃, the cooling speed is 6-20 ℃ per unit time, and the final cooling temperature is 480-590 ℃; directly feeding the rolled piece plate into a straightener after leaving an ultra-fast cooling system, straightening for 1-3 times at the temperature, then naturally cooling by a cooling bed, and cold straightening by a cooling bed when the surface temperature of the rolled piece plate is below 200 ℃ to obtain a large composite plate.

According to the embodiment, the heating and rolling technology is adopted, and parameters such as the heating temperature, the heating time, the heat preservation time, the temperature in rolling, the rolling reduction, the temperature in cooling, the cooling speed and the like are controlled, so that the mechanical property of the finally obtained composite board can be ensured, and the reduction of the corrosion resistance of the composite board due to the preparation process of the composite board can be avoided.

< second embodiment >

This embodiment is identical to the first embodiment of the composite-blank rolling stage described above in terms of the heating and rolling steps, and differs in that: and (3) a cooling step. Only this cooling step will be described below.

Specifically, the cooling step in this embodiment is:

after exiting the rolling mill, the rolled piece plate enters an ultra-fast cooling system for intermittent cooling; the ultra-fast cooling system has 24 sets of cooling headers arranged at 1m intervals along the roller table, each set of cooling headers having a cooling distance of 1m. When the rolled piece plate passes through the ultra-fast cooling system, the opening and closing states of all 24 groups of cooling headers are controlled in a mode that N groups of cooling headers are opened every time and then M groups of cooling headers are not opened, the cooling water pressure is 0.15-0.30 MPa, the cooling speed is 3-15 ℃ per unit of time, and the final cooling temperature is 380-590 ℃; wherein N takes the value of 2, 3 or 4, M takes the value of 2, 3 or 4;

And (5) naturally cooling the rolled piece plate to room temperature by a cooling bed after leaving the ultra-rapid cooling system to obtain the large composite plate.

In addition to the advantages of the first embodiment, the present embodiment may also be used to make the composite board large board travel in the cooling header and the cooling header that are alternately turned on and not turned off when the composite board large board passes through the ultra-fast cooling system by adopting the intermittent cooling mode, so that each part of the composite board large board is cooled, reddened, cooled and reddened … … is circulated until the composite board large board leaves the ultra-fast cooling system; in this way, in the cooling-reddening cycle of the composite board large board, the carbon steel substrate continuously generates the phase change and self-tempering effects, and the phase change reaction gradually permeates into the core until the whole carbon steel substrate is phase-changed; the intermittent cooling process is different from the conventional reciprocating cooling, the reversion and self-tempering of the reciprocating cooling are carried out after the phase change of the surface layer or the near surface layer is finished, the difference of the temperature difference or the cooling speed between the surface layer and the core is larger, the difference of the tissue and the mechanical property is also larger, but the intermittent cooling process of the embodiment is that the composite board big board is in a cooling state at the same time, and the reversion/self-tempering is carried out at some parts, and each part of the composite board big board is alternately cooled and reversion/self-tempered along with time, so that the difference of the temperature, the cooling speed, the tissue, the performance and the like of the composite board big board on the surface layer and the core is smaller, for example, the difference of Vickers hardness in the thickness direction of the base layer of the finally obtained composite board is less than or equal to 10, the difference of the strength between the head and the tail is less than or equal to 40MPa, and the strength difference of the whole board is less than or equal to 40 MPa. Meanwhile, the shape of the composite board can be further improved through intermittent cooling, namely, the unevenness is low, and even if the composite board is cooled by a cooling bed directly without straightening after cooling is finished, the excellent shape can be obtained.

Further preferably, during the intermittent cooling process: if the thickness of the rolled piece plate is below 54mm, for example, the thickness is 10-54 mm, the roller speed of the ultra-rapid cooling system is 0.4-0.8 m//, the cooling headers of the 1 st-4 th group are opened, the cooling headers of the 5 th-6 th group are not opened, the cooling headers of the 7 th-8 th group are opened, the cooling headers of the 9 th-10 th group are not opened, the cooling headers of the 11 th-12 th group are opened, the cooling headers of the 13 th-14 th group are not opened, the cooling headers of the 15 th-16 th group are opened, the cooling headers of the 17 th-18 th group are not opened, the cooling headers of the 19 th-20 th group are opened, the cooling headers of the 21 st-22 th group are not opened, and the cooling headers of the 23-24 th group are opened; the rolled piece plate passes through the ultra-fast cooling system once to finish intermittent cooling.

Further preferably, in the intermittent cooling: if the thickness of the rolled piece plate is more than 54mm, the roller way speed of the ultra-fast cooling system is more than 0.2m// and less than 0.6m// and the cooling headers of the 1 st to 4 th groups are opened, the cooling headers of the 5 th to 8 th groups are not opened, the cooling headers of the 9 th to 12 th groups are opened, the cooling headers of the 13 th to 16 th groups are not opened, the cooling headers of the 17 th to 20 th groups are opened, the cooling headers of the 21 st to 22 th groups are not opened, and the cooling headers of the 23 rd to 24 th groups are opened; the rolled piece plate passes through the ultra-fast cooling system once to finish intermittent cooling. Thus, the control of the plate shape and the uniformity of the thick plate of the stainless steel composite plate are realized, and the production difficulty of the thick plate of the conventional stainless steel composite plate is overcome.

< third embodiment >

This embodiment is identical to the second embodiment of the composite-blank rolling stage described above in terms of the cooling step, except that: a heating step and a rolling step. Only the heating step and the rolling step will be described below.

Specifically, in this embodiment, the heating step is:

five-stage heating of preheating, one heating, two heating, three heating and soaking is adopted for the obtained composite blank, the preheating temperature is less than or equal to 850 ℃, the retention time is (0.45-0.55) t min/mm, the heating temperature is 1030-1090 ℃, the retention time is (0.35-0.45) t min/mm, the two heating temperatures are 1100-1160 ℃, the retention time is (0.25-0.35) t min/mm, the three heating temperatures are 1140-1180 ℃, the retention time is (0.15-0.25) t min/mm, the soaking temperature is 1170-1210 ℃, the retention time is (0.10-0.20) t min/mm, and t is the thickness of the composite blank.

The rolling steps are as follows:

Compared with the prior art, the intermittent cooling is adopted in the embodiment similar to the second embodiment, and the intermittent cooling process and the stacking cooling process have the beneficial effects. Further, compared with the prior art, the heating technology of the embodiment can better control the heating rate of the composite blank in each section, ensure the blank to be heated uniformly, avoid cracking and air leakage of the composite blank caused by the difference of the material thermal properties of the base material and the composite material of the composite blank, and further ensure the interface bonding effect; moreover, the rolling process of the embodiment adopts the modes of longitudinal rolling, transverse rolling and longitudinal rolling, so that the realization of rolling under high pressure can be ensured, the core of the composite blank can be effectively permeated, the deformation of the core is promoted, and the combination rate of a composite interface is ensured; when the temperature is reached, an instant cooling device is adopted for cooling, so that the temperature reaching time is reduced, the rolling efficiency is improved, and meanwhile, the overlength of the temperature reaching time is avoided, and the crystal grains of the carbon steel base material grow; and the temperature control in the finish rolling stage can refine grains and ensure that the thick plate of the composite plate has good low-temperature impact toughness.

It will be appreciated that, as a further alternative embodiment, the heating step and rolling step provided in this embodiment may also be combined with the cooling step of the first embodiment described above to produce a composite board panel, and the advantages achieved in this embodiment may also be achieved accordingly.

The above description of the rolling stage of the composite billet is detailed, and the preparation method further includes a dividing step and a straightening step. These two steps are described in detail below.

< step of separating plate >

Cutting the edge of the obtained large composite board by a plasma cutting machine to remove the part outside the seal, wherein the large composite board is separated into an upper composite board small board and a lower composite board small board; as shown in fig. 5, one of the composite board platelets is a single-sided stainless steel composite board platelet composed of a base layer 1 (made of a base material 1) and a composite layer 5 (made of a composite material 5), and the other composite board platelet is a single-sided stainless steel composite board platelet composed of a base layer 2 (made of a base material 2), a composite layer 3 (made of a composite material 3) and a composite layer 4 (made of a composite material 4).

In this step, it may further include: the single-sided stainless steel composite board panel composed of the base layer 2 (made of the base material 2), the clad layer 3 (made of the clad material 3) and the clad layer 4 (made of the clad material 4) is further divided into a single-sided stainless steel composite board panel composed of a part 2a of the base layer 2 and the clad layer 3, and a single-sided stainless steel composite board panel composed of another part 2b of the base layer 2 and the clad layer 4.

It will be appreciated that the dividing positions of the portions 2a and 2b of the base layer 2 may be located between the hypotenuse of the ply 3 and the hypotenuse of the ply 4 as shown in fig. 5, i.e. the dividing boundary is spaced from the hypotenuse of the ply 3 by a distance in the Y-direction, while the hypotenuse of the ply 4 is also spaced from the hypotenuse by a distance in the Y-direction. This is the case: in the single-sided stainless steel composite board small plate formed by a part 2a of the base layer 2 and the composite layer 3, three sides of the composite layer 3 are flush with three sides of the part 2a of the base layer 2, and the bevel edge of the composite layer 3 is positioned in the middle of the surface of the part 2a of the base layer 2; in the single-sided stainless steel composite board small plate formed by the other part 2b of the base layer 2 and the composite layer 4, three sides of the composite layer 4 are flush with three sides of the part 2b of the base layer 2, and the bevel edge of the composite layer 4 is positioned in the middle of the surface of the part 2b of the base layer 2. In this way, one end of the two formed stainless steel composite boards (as shown in figure 5) is a composite structure formed by carbon steel and stainless steel, and the end can be like the existing composite board, has the corrosion resistance of a composite layer and has good mechanical properties of a base layer; the other end is a carbon steel plate, so that the problem of the conventional dissimilar welding is avoided in the use process of the stainless steel composite plate, the firmness in the use process is high, the production difficulty is low, the cost is low, the construction efficiency is high, and the layout of the whole structural member of the bridge is influenced because no step exists between the edge of the stainless steel composite layer and the steel plate for the bridge structure.

Instead, as an alternative embodiment, the dividing positions of the portion 2a and the portion 2b of the base layer 2 may be set by taking the lower edge of the hypotenuse of the composite layer 3 as the dividing boundary, so that: in the single-sided stainless steel composite board small plate formed by a part 2a of the base layer 2 and the composite layer 3, four sides of the composite layer 3 are flush with four sides of the part 2a of the base layer 2; in the single-sided stainless steel composite board small plate formed by the other part 2b of the base layer 2 and the composite layer 4, three sides of the composite layer 4 are flush with three sides of the part 2b of the base layer 2, and the bevel edge of the composite layer 4 is positioned in the middle of the surface of the part 2b of the base layer 2.

< straightening step >

In the step, the stainless steel composite board obtained by splitting is subjected to sizing, flattening and cold straightening, and a single-sided stainless steel composite board finished product is obtained.

Further, an embodiment of the present invention also provides a single-sided stainless steel composite plate, which is prepared by the preparation method described above, and is composed of a carbon steel base layer 1 and a stainless steel cladding layer 5 as shown in fig. 1 or 5. The pair of side edges of the clad layer 5 in the X direction are flush with the pair of side edges of the base layer 1 in the X direction, and the pair of side edges of the clad layer 5 in the Y direction are located in the middle of the surface of the base layer 1. This type of composite plate may be referred to as a middle stainless steel composite plate. Therefore, the middle part of the stainless steel composite board is a composite structure formed by the carbon steel base layer 1 and the stainless steel composite layer 5, so that the stainless steel composite board has the corrosion resistance of the composite layer 5 as the existing composite board, and has good mechanical properties of the base layer 1; the two ends of the stainless steel composite board are purely carbon steel base layers 1 which are directly integrally formed with the composite structure, and the carbon steel base layers 1 at the two ends can be directly used in engineering to save welding, so that the stainless steel composite board avoids the existing dissimilar welding problem in use, and has strong firmness, low production difficulty, low cost and high construction efficiency in use.

The pair of sides of the composite layer 5 in the Y direction are inclined sides forming an obtuse angle with the upper surface of the composite layer 5, so that a right-angle step is not formed between the inclined sides and the carbon steel base layer 1 to influence the layout of the bridge integral structural member.

Furthermore, the stainless steel composite plate also has excellent mechanical property and corrosion resistance, and has excellent plate shape, interface bonding quality, uniformity, impact toughness and surface quality compared with the prior art. Specifically, the unevenness of the composite board is less than or equal to 3mm/m, even less than or equal to 2mm/m; the bonding rate of the composite interface is 100%, and the shearing strength is more than or equal to 300MPa; the yield strength is more than or equal to 345MPa, the tensile strength is more than or equal to 490MPa, the elongation after breaking is more than or equal to 18%, and the yield ratio is less than or equal to 0.86; the Vickers hardness difference in the thickness direction of the base layer 1 of the composite board is less than or equal to 10, the strength difference between the head and the tail is less than or equal to 40MPa, and the strength difference of the whole board is less than or equal to 40MPa; the impact energy at 0 ℃ is more than or equal to 240J, the impact energy at-20 ℃ is more than or equal to 200J, and the impact energy at-40 ℃ is more than or equal to 150J; the outer bending is 180 degrees free of cracks, and the inner bending is 180 degrees free of cracks; after boiling in sulfuric acid-copper sulfate solution for 20h and bending at 180 DEG, the composite layer 5 has no intergranular corrosion cracks.

In addition, an embodiment of the present invention provides another single-sided stainless steel composite board, which is prepared by the preparation method described above, and is composed of a carbon steel base layer 2 for bridge construction and a stainless steel composite layer 3 (or 4) as shown in fig. 5. Three sides (for example, two sides in the X direction and one side in the Y direction) of the clad layer 3 (or 4) are flush with the three sides of the base layer 2; the other side edge (e.g., the other side edge in the Y direction) of the clad layer 3 (or 4) is located in the middle of one surface of the base layer 2. This type of composite panel may be referred to as a single ended stainless steel composite panel. Therefore, one end of the stainless steel composite board is a composite structure formed by the carbon steel base layer 2 and the stainless steel composite layer 3 (or 4), and the stainless steel composite board has the corrosion resistance of the composite layer 3 (or 4) and good mechanical property of the base layer 2 as the existing composite board; the other end of the stainless steel composite board is a pure carbon steel base layer 2, the stainless steel composite board and the composite structure are directly integrally formed, and the stainless steel composite board can be directly used in engineering to save welding, so that the stainless steel composite board avoids the existing dissimilar welding problem in use, and has strong firmness, low production difficulty, low cost and high construction efficiency in use.

The side edge of the composite layer 3 (or 4) located in the middle of the surface of the base layer 2 is provided with an obtuse angle bevel edge with the upper surface of the composite layer 3 (or 4), so that a right angle step is not formed between the bevel edge and the carbon steel base layer 2 to influence the layout of the bridge integral structural member.

Furthermore, the stainless steel composite plate also has excellent mechanical property and corrosion resistance, and has excellent plate shape, interface bonding quality, uniformity, impact toughness and surface quality compared with the prior art. Specifically, the unevenness of the composite board is less than or equal to 3mm/m, even less than or equal to 2mm/m; the bonding rate of the composite interface is 100%, and the shearing strength is more than or equal to 300MPa; the yield strength is more than or equal to 345MPa, the tensile strength is more than or equal to 490MPa, the elongation after breaking is more than or equal to 18%, and the yield ratio is less than or equal to 0.86; the Vickers hardness difference in the thickness direction of the base layer 2 of the composite board is less than or equal to 10, the strength difference between the head and the tail is less than or equal to 40MPa, and the strength difference of the whole board is less than or equal to 40MPa; the impact energy at 0 ℃ is more than or equal to 240J, the impact energy at-20 ℃ is more than or equal to 200J, and the impact energy at-40 ℃ is more than or equal to 150J; the outer bending is 180 degrees free of cracks, and the inner bending is 180 degrees free of cracks; after boiling in sulfuric acid-copper sulfate solution for 20h and bending at 180 °, the clad layer 3 (or 4) is free of intergranular corrosion cracking.

The above detailed description is merely illustrative of possible embodiments of the present invention, which should not be construed as limiting the scope of the invention, and all equivalent embodiments or modifications that do not depart from the spirit of the invention are intended to be included in the scope of the invention.

The advantages of the invention will be further illustrated by the following examples, which are, of course, only some, but not all of the many variations encompassed by the invention.

Examples 1 to 6

In these examples, the steel grade/chemical composition of the selected composite and substrate materials are shown in table 1, respectively. Wherein, the "-" is characterized in that no corresponding element (the content is zero or close to zero) is actively added in the preparation process of the steel billet.

TABLE 1

The preparation method according to an embodiment of the present invention was carried out with the base material and the composite material in table 1 above. For each example, the base material and composite material used are shown in table 2; examples 1 to 2 were carried out according to the first embodiment of the clad-rolling stage, examples 3 to 4 were carried out according to the second embodiment of the clad-rolling stage, and examples 5 to 6 were carried out according to the third embodiment of the clad-rolling stage in examples 1 to 6.

Examples 1 to 6 each produced three single-sided stainless steel composite board products, as shown in fig. 5, comprising a middle composite board with both ends being purely carbon steel base layer, middle being carbon steel base layer and stainless steel cladding, two single-sided composite boards with one end being purely carbon steel base layer, and the other end being carbon steel base layer and stainless steel cladding, the total thickness, base layer thickness, cladding thickness, and composite board type of the produced single-sided stainless steel composite board products are shown in table 2.

TABLE 2

Sampling and testing all three stainless steel composite plates obtained in each embodiment, wherein the interface bonding rate of each composite plate is 100%, and the shearing strength is more than or equal to 300MPa; the inner bending is qualified by 180 degrees (no crack), and the outer bending is qualified by 180 degrees (no crack); and the composite layer has no intergranular corrosion cracks after being boiled in sulfuric acid-copper sulfate solution for 20 hours and bent by 180 degrees; the impact energy at 0 ℃ is more than or equal to 240J, the impact energy at-20 ℃ is more than or equal to 200J, and the impact energy at-40 ℃ is more than or equal to 150J; the yield strength is more than or equal to 345MPa, the tensile strength is more than or equal to 490MPa, the elongation after breaking is more than or equal to 18%, and the yield ratio is less than or equal to 0.86; and, the unevenness was not more than 3mm/m, examples 3 to 6 and even not more than 2mm/m.

Claims

1. The utility model provides a single face stainless steel composite sheet, its characterized in that, the composite sheet is formed by the complex of the carbon steel basic unit of below and the stainless steel complex layer of top, the complex layer in the X direction both sides limit with the basic unit is in the X direction both sides limit respectively flushes, the complex layer in the Y direction both sides limit all is located the inside of the upper surface of basic unit.

2. The single-sided stainless steel composite panel according to claim 1, wherein one or both sides of the clad layer in the Y direction are provided as oblique sides having an obtuse angle with respect to the upper surface of the clad layer.

3. The single-sided stainless steel composite panel according to claim 1, wherein both sides of the clad layer in the Y direction are at the same angle as the upper surface of the clad layer.

4. The single-sided stainless steel composite panel according to claim 1, wherein the composite panel has a total thickness of 15-39 mm, a base layer thickness of 12-36 mm, and a multi-layer thickness of 3mm.

5. The single-sided stainless steel composite panel according to claim 1, wherein the composite panel has a flatness of 2mm/m or less.

6. The preparation method of the single-sided stainless steel composite board is characterized by comprising the following steps of:

7. The method of manufacturing a single-sided stainless steel composite panel according to claim 6, wherein the joined sides of composite material a and composite material B are each oblique sides of width V1, and in the composite blank base, the joined oblique sides of composite material a and composite material B are parallel and opposite.

8. The method of manufacturing a single-sided stainless steel composite panel according to claim 7, wherein the joined sides of the composite material B and the composite material C are each oblique sides of the width V2, and in the composite blank base, the joined oblique sides of the composite material B and the composite material C are parallel and opposite.

9. The method for manufacturing a single-sided stainless steel composite plate according to claim 8, wherein both oblique sides of the composite material B form an obtuse angle with the non-to-be-composite surface of the composite material B.

10. The method for producing a single-sided stainless steel composite sheet according to claim 6, wherein l1=l2+90 to 150mm, w1=w21+w22+w23-v1-v2+90 to 150mm.

11. The method for preparing the single-sided stainless steel composite plate according to claim 6, wherein the step of vacuumizing, sealing, heating, rolling, cooling, separating and straightening the composite blank substrate comprises the following steps:

12. The method for preparing the single-sided stainless steel composite plate according to claim 6, wherein the step of vacuumizing, sealing, heating, rolling, cooling, separating and straightening the composite blank substrate comprises the following steps:

13. The method for preparing the single-sided stainless steel composite plate according to claim 6, wherein the step of vacuumizing, sealing, heating, rolling, cooling, separating and straightening the composite blank substrate comprises the following steps: