Composite steel plate, preparation method thereof, composite steel pipe and application

Abstract

The invention relates to the technical field of pipeline production, and discloses a composite steel plate, a preparation method thereof, a composite steel pipe and application. The composite steel plate comprises a hydrogen permeation resisting layer and a reinforcing layer arranged on one side face of the hydrogen permeation resisting layer. Wherein the hydrogen permeation resisting layer and the reinforcing layer are made of pipeline steel, and the ratio of the yield strength of the hydrogen permeation resisting layer to the yield strength of the reinforcing layer is 1: (1.5-1.7). On the basis, the composite steel pipe is manufactured by forming and welding the composite steel plate. According to the composite steel pipe, the composite steel plate obtained by conducting composite rolling on the specific low-grade pipeline steel and the high-grade pipeline steel serves as a pipe manufacturing material, the hydrogen embrittlement resistance and the pipeline strength can be well considered, and the application requirement for large-air-volume, efficient and long-distance transportation of hydrogen energy is met.

Description

Technical Field

[0001] The present invention relates to the technical field of pipeline production, and in particular to a composite steel plate and a preparation method thereof, a composite steel pipe and applications thereof. Background Art

[0002] As an important chemical raw material, hydrogen energy is widely used in petrochemical, metallurgical, organic synthesis and other fields. In the industrial production and application of hydrogen energy, specifically, in the production stage of hydrogen energy, the hydrogen generated in the hydrogen generator needs to be transported to the hydrogen storage device; in the utilization stage of hydrogen energy, the hydrogen in the hydrogen storage device needs to be transported to the production unit or energy conversion unit for utilization. Conventional hydrogen energy transportation equipment is a long-tube trailer. This mode of transportation is increasingly difficult to meet the needs of use due to its short transportation distance and low transportation volume. Compared with long-tube trailers, pipeline transportation has important advantages such as larger gas transmission volume and low energy consumption, and is expected to become an alternative to the former.

[0003] At present, long-distance hydrogen pipelines have not been widely used in the market. The total mileage of hydrogen pipelines in the world is only about 4,600 km, of which the United States has the largest hydrogen pipeline, with a total mileage of 2,720 km. Currently, most hydrogen pipelines use seamless steel pipes, and the hydrogen pressure is generally 2-10 MPa. The pipeline material is mainly low-strength pipeline steel, and due to process reasons, the pipe diameter is small (the inner diameter is usually <610 mm), resulting in low hydrogen transmission efficiency and high pipeline construction costs. So far, large gas transmission and long-distance transportation have not been achieved, which greatly restricts the application effect of pipeline hydrogen transmission.

[0004] Therefore, developing a new type of hydrogen pipeline that combines excellent hydrogen embrittlement resistance and pipeline strength is of great significance for achieving large-volume, high-efficiency, and long-distance transportation of hydrogen energy. Summary of the invention

[0005] The purpose of the present invention is to overcome the problem that the existing hydrogen transmission pipeline cannot meet the requirements of large volume, high efficiency and long-distance transportation, and to provide a composite steel plate and a preparation method thereof, a composite steel pipe and application.

[0006] In order to achieve the above object, the present invention provides a composite steel plate in a first aspect, comprising a hydrogen permeation resistant layer and a reinforcement layer provided on one side of the hydrogen permeation resistant layer;

[0007] The material of the hydrogen permeation resistant layer and the reinforcement layer is pipeline steel, and the ratio of the yield strength of the hydrogen permeation resistant layer to the yield strength of the reinforcement layer is 1:(1.5-1.7).

[0008] A second aspect of the present invention provides a method for preparing a composite steel plate, comprising:

[0009] (1) superimposing and welding a first steel billet and a second steel billet to obtain a composite billet;

[0010] (2) rolling and cutting the composite billet to obtain a composite steel plate;

[0011] Wherein, the first steel billet and the second steel billet are made of pipeline steel;

[0012] In the composite steel plate, the yield strength ratio of the hydrogen permeation resistant layer formed by the first steel billet to the reinforcing layer formed by the second steel billet is 1:(1.5-1.7).

[0013] The third aspect of the present invention provides a composite steel plate produced by the method described in the second aspect.

[0014] The fourth aspect of the present invention provides a composite steel pipe, which is obtained by forming and welding the composite steel plate described in the first aspect or the third aspect;

[0015] Among them, the inner wall of the composite steel pipe is the anti-hydrogen permeation layer of the composite steel plate, and the outer wall of the composite steel pipe is the reinforcement layer of the composite steel plate.

[0016] The fifth aspect of the present invention provides application of the composite steel pipe described in the fourth aspect in the field of hydrogen energy transportation.

[0017] Through the above technical solution, the present invention can achieve the following beneficial effects:

[0018] (1) The composite steel pipe provided by the present invention uses a composite steel plate obtained by composite rolling of a specific low-grade pipeline steel and a high-grade pipeline steel as a pipe material, which can well balance the hydrogen embrittlement resistance and pipeline strength, and meet the application needs of large-volume, high-efficiency, long-distance and high-pressure transportation of hydrogen energy;

[0019] (2) The manufacturing process is simple, feasible, and cost-saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention but do not constitute a limitation of the present invention. In the accompanying drawings:

[0021] Figure 1 It is a schematic diagram of the layer structure of the composite steel plate provided by the present invention (side view).

[0022] Figure 2 The present invention provides a process flow chart for preparing the composite steel plate.

[0023] Figure 3 It is a schematic cross-sectional view of the composite steel pipe provided by the present invention.

[0024] Figure 4 The present invention provides a process flow chart for preparing the composite steel pipe.

[0025] Description of Reference Numerals

[0026] 1-Hydrogen permeation resistance layer 2-Reinforcement layer 3-Inner wall of composite steel pipe

[0027] 4-Outer wall of composite steel pipe 5-Inner wall weld of composite steel plate 6-Outer wall weld of composite steel plate DETAILED DESCRIPTION

[0028] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0029] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0030] A first aspect of the present invention provides a composite steel plate, the composite steel plate comprising a hydrogen permeation resistant layer, and a reinforcement layer disposed on one side of the hydrogen permeation resistant layer;

[0031] The material of the hydrogen permeation resistant layer and the reinforcement layer is pipeline steel, and the ratio of the yield strength of the hydrogen permeation resistant layer to the yield strength of the reinforcement layer is 1:(1.5-1.7).

[0032] The composite steel plate provided by the present invention has a composite layer structure, such as Figure 1 As shown, the composite steel plate includes an anti-hydrogen permeation layer 1 and a reinforcement layer 2, wherein the reinforcement layer 2 is provided on the surface of any one of the two side surfaces of the anti-hydrogen permeation layer 1. The anti-hydrogen permeation layer 1 has hydrogen embrittlement resistance, and the reinforcement layer 2 has high strength. The composite steel plate adopts a composite method of "same material type + different material grade" between different layer structures. Specifically, the materials of the anti-hydrogen permeation layer 1 and the reinforcement layer 2 are both pipeline steel, and the steel grade of the pipeline steel used in the anti-hydrogen permeation layer 1 is lower than the steel grade of the pipeline steel used in the reinforcement layer 2. Furthermore, the ratio of the yield strength of the anti-hydrogen permeation layer 1: the yield strength of the reinforcement layer 2 is 1: (1.5-1.7). The composite steel plate provided by the present invention has the above-mentioned layer structure and layer function, and can have excellent hydrogen embrittlement resistance, mechanical properties and processing properties.

[0033] According to the present invention, the anti-hydrogen permeation layer 1 has a hydrogen embrittlement resistance effect. In the present invention, the "hydrogen embrittlement" refers to the process in which the steel material is in long-term contact with hydrogen, hydrogen atoms diffuse and enter the metal lattice of the steel material, and the hydrogen atoms polymerize into hydrogen molecules, causing stress concentration, exceeding the strength limit of the steel material, forming fine cracks inside the steel material, and then deteriorating the mechanical properties of the steel material, resulting in embrittlement or even cracking.

[0034] According to the present invention, in the composite steel plate, the material of the anti-hydrogen permeation layer 1 can be selected from low-grade pipeline steel, preferably at least one of L290 pipeline steel, L320 pipeline steel, L360 pipeline steel and L390 pipeline steel. Under the condition of meeting the above material requirements, the anti-hydrogen permeation layer 1 can have excellent hydrogen embrittlement resistance and meet the processing and certain pressure requirements in terms of mechanical properties.

[0035] According to the present invention, in the composite steel plate, the material of the reinforcement layer 2 can be selected from high-grade pipeline steel, preferably L485 pipeline steel and / or L555 pipeline steel. When the above material requirements are met, the reinforcement layer 2 can have excellent mechanical properties, especially excellent strength and pressure bearing properties.

[0036] In the present invention, the L290 pipeline steel, L320 pipeline steel, L360 pipeline steel, L390 pipeline steel, L485 pipeline steel and L555 pipeline steel refer to the pipeline steel materials specified in GB / T 9711-2017 (Steel pipes for pipeline transportation systems in the petroleum and natural gas industry), where "L" is the L in "Pipeline" in English, and the number after "L" represents the yield strength. The pipeline steels of the above specifications can be prepared by conventional methods or purchased commercially.

[0037] According to the present invention, in the composite steel plate, the thickness of the anti-hydrogen permeation layer 1 can be 3-5 mm. If the thickness of the anti-hydrogen permeation layer 1 is too small, the ability to resist hydrogen permeation will be insufficient; if the thickness of the anti-hydrogen permeation layer 1 is too large, the overall structural strength of the composite steel plate will be insufficient.

[0038] According to the present invention, preferably, the thickness of the anti-hydrogen permeation layer 1 is 3.5-4.5 mm, such as 3.5 mm, 3.6 mm, 3.7 mm, 3.8 mm, 3.9 mm, 4.0 mm, 4.1 mm, 4.2 mm, 4.3 mm, 4.4 mm, 4.5 mm, and any value in the range of any two of the above values.

[0039] According to the present invention, in the composite steel plate, the thickness of the reinforcement layer 2 can be 10-30 mm. If the thickness of the reinforcement layer 2 is too small, the overall structural strength of the composite steel plate will be insufficient; if the thickness of the reinforcement layer 2 is too large, the composite steel plate's ability to resist hydrogen penetration will be affected.

[0040] According to the present invention, preferably, the thickness of the reinforcing layer 2 is 16.5-17.5 mm, for example, 16.5 mm, 16.6 mm, 16.7 mm, 16.8 mm, 16.9 mm, 17.0 mm, 17.1 mm, 17.2 mm, 17.3 mm, 17.4 mm, 17.5 mm, and any value in the range consisting of any two of the above values.

[0041] According to the present invention, in the composite steel plate, the anti-hydrogen permeation layer 1 and the reinforcement layer 2 each satisfy the above-mentioned thickness limitations. Preferably, the thickness ratio of the anti-hydrogen permeation layer 1: reinforcement layer 2 is 1: (3-10), thereby making the composite steel plate have better hydrogen embrittlement resistance, mechanical properties and processing properties.

[0042] According to the present invention, in the composite steel plate, the anti-hydrogen permeation layer 1 and the reinforcement layer 2 are composited by welding.

[0043] According to the present invention, the tensile property loss rate of the composite steel plate is ≤4%, and the composite steel plate has excellent hydrogen embrittlement resistance.

[0044] According to the present invention, the yield strength of the composite steel plate is ≥435 MPa, and more preferably 500-625 MPa, and has excellent strength and pressure bearing properties.

[0045] A second aspect of the present invention provides a method for preparing a composite steel plate, comprising:

[0046] (1) superimposing and welding a first steel billet and a second steel billet to obtain a composite billet;

[0047] (2) rolling and cutting the composite billet to obtain a composite steel plate;

[0048] Wherein, the first steel billet and the second steel billet are made of pipeline steel;

[0049] In the composite steel plate, the yield strength ratio of the hydrogen permeation resistant layer formed by the first steel billet to the reinforcing layer formed by the second steel billet is 1:(1.5-1.7).

[0050] According to the present invention, in step (1), the material of the first steel billet can be selected from low-grade pipeline steel, preferably at least one of L290 pipeline steel, L320 pipeline steel, L360 pipeline steel and L390 pipeline steel.

[0051] According to the present invention, in step (1), the material of the reinforcement layer 2 can be selected from high-grade pipeline steel, preferably L485 pipeline steel and / or L555 pipeline steel.

[0052] According to the present invention, in step (1), the overlapping process preferably first processes the first steel billet and the second steel billet to the same size, grinds the surfaces to be composited of the two, and then completely contacts the surfaces to be composited of the two to achieve overlapping.

[0053] According to the present invention, in step (1), the welding is preferably performed by vacuum electron beam welding, which can obtain better welding strength.

[0054] According to the present invention, the conditions for vacuum electron beam welding include: vacuum degree ≤ 5×10 -2 Pa; welding current is 20-60mA, welding voltage is 40-60kV, and welding speed is 0.6-1.2m / min.

[0055] According to the present invention, in step (2), the rolling includes rough rolling and finish rolling.

[0056] The starting rolling temperature of the rough rolling is 1175-1225°C, and the finishing rolling temperature is 885-915°C.

[0057] The start rolling temperature of the finish rolling is 825-875°C, and the final rolling temperature is 785-815°C.

[0058] According to the present invention, preferably, in the composite steel plate, the thickness of the hydrogen permeation resistant layer formed by the first steel billet is 3-5 mm.

[0059] According to the present invention, preferably, in the composite steel plate, the thickness of the reinforcement layer formed by the second steel billet is 10-30 mm.

[0060] In the present invention, the method for preparing the composite steel plate comprises the above steps (1) and (2). Specifically, according to a preferred embodiment of the present invention, Figure 2 The process flow shown implements the method for preparing the composite steel plate:

[0061] (1-1) pre-treating the first steel billet (thickness 3-5 mm) and the second steel billet (thickness 10-30 mm), wherein the pre-treating includes cutting the first steel billet and the second steel billet into the same size and grinding the surfaces to be composited;

[0062] (1-2) The surfaces of the first steel billet and the second steel billet to be composited after the raw material pretreatment are brought into contact, so that the first steel billet and the second steel billet are completely overlapped and combined into a blank to be welded, and then welded to obtain a composite billet; in the specific implementation process, one sheet of the first steel billet and one sheet of the second steel billet can be overlapped, or a plurality of sheets can be overlapped, preferably a plurality of sheets are overlapped, for example, two sheets of the first steel billet and two sheets of the second steel billet are each taken, and the stacking is carried out in the order of "second steel billet → first steel billet → first steel billet → second steel billet" from bottom to top; during the overlapping process, a high temperature resistant insulating agent is injected between two adjacent first steel billets; the composite billet obtained by this overlapping method contains two groups of "first steel billet + second steel billet", which can ensure the symmetry of the subsequent rolling stress, thereby ensuring the uniformity of rolling deformation and the dimensional accuracy of the composite steel plate finally obtained; the welding is preferably carried out by vacuum electron beam welding (welding conditions include: vacuum degree ≤5×10 -2 Pa; welding current is 20-60mA, welding voltage is 40-60kV, welding speed is 0.6-1.2m / min);

[0063] (1-3) heating the composite billet to 1150-1250° C. and keeping the temperature for 2-6 hours, wherein the uniformity of the overall temperature of the rolled billet can be ensured by the heating treatment; then descaling the composite billet, preferably by high-pressure water descaling;

[0064] (2-1) symmetrically rolling the dephosphorized composite billet, specifically, sequentially performing rough rolling (the starting rolling temperature of the rough rolling is 1175-1225° C., and the final rolling temperature is 885-915° C.), finishing rolling (the starting rolling temperature of the finishing rolling is 825-875° C., and the final rolling temperature is 785-815° C.), and cooling and hot straightening the rolled sheet to obtain a rolled product;

[0065] (2-2) heating the rolled piece to 450-550° C. and keeping the temperature for 1-2 hours. The heat treatment can eliminate the stress between the composite layers in the rolled piece and improve the intergranular corrosion resistance. Then, pre-cutting and separating the rolled piece. Preliminary control of the product size is achieved through pre-cutting and separation. For the case where multiple groups are stacked in step (1-2), the multiple groups of "first steel plate + second steel plate" in the rolled piece can also be separated through pre-cutting and separation to obtain multiple composite steel plate pre-products (for the case where a first steel billet and a second steel billet are stacked in step (1-2), a composite steel plate pre-product is obtained here accordingly). Then, the composite steel plate pre-product is subjected to cold straightening and ultrasonic flaw detection to obtain a rough product.

[0066] (2-3) The rough product is sequentially subjected to fine shearing, fine straightening and surface treatment to obtain a composite steel plate; the composite steel plate obtained comprises an anti-hydrogen permeation layer and a reinforcement layer arranged on one side of the anti-hydrogen permeation layer; wherein the anti-hydrogen permeation layer and the reinforcement layer are made of pipeline steel, and the ratio of the yield strength of the anti-hydrogen permeation layer to the yield strength of the reinforcement layer is 1:(1.5-1.7); the thickness of the anti-hydrogen permeation layer is 3-5 mm, and the thickness of the reinforcement layer is 10-30 mm.

[0067] The third aspect of the present invention provides a composite steel plate produced by the method described in the second aspect.

[0068] According to the present invention, the structure and performance of the composite steel plate prepared by the method described in the second aspect are the same as those of the composite steel plate described in the first aspect of the present invention, and will not be described in detail herein.

[0069] The fourth aspect of the present invention provides a composite steel pipe, which is obtained by forming and welding the composite steel plate described in the first aspect or the third aspect;

[0070] Among them, Figure 3 As shown, the inner wall 3 of the composite steel pipe is the anti-hydrogen permeation layer of the composite steel plate, and the outer wall 4 of the composite steel pipe is the reinforcement layer of the composite steel plate.

[0071] According to the present invention, in the preparation method of the composite steel pipe, the conventional straight seam steel pipe forming, welding process and parameters can be used for pipe making and welding, preferably the JCOE (straight seam double-sided submerged arc welded pipe) process is used for pipe making and welding, and it is further preferred to use low-grade steel wire in the internal welding process during the welding process. Specifically, the low-grade steel wire is required to obtain the inner wall weld 5 of the composite steel plate with pearlite structure as the main structure after welding, so that the strength of the inner wall weld 5 of the composite steel plate is equivalent to the strength of the anti-hydrogen penetration layer in the composite steel plate, and high-grade steel wire is used in the external welding process. It is required that the high-grade steel wire is required to obtain the outer wall weld 6 of the composite steel plate with ferrite structure as the main structure after welding, so that the strength of the outer wall weld 6 of the composite steel plate is equivalent to the strength of the reinforcement layer in the composite steel plate).

[0072] According to a preferred embodiment of the present invention, it is possible to use Figure 4 The process flow shown implements the preparation method of the composite steel pipe:

[0073] (I) Ultrasonic plate detection: The composite steel plate is subjected to full plate ultrasonic inspection to ensure that there is no excess Delamination defects of the equivalent size of a flat-bottom hole (i.e. 6mm diameter);

[0074] (II) Edge milling: using an edge milling machine to mill the two edges of the composite steel plate to achieve the target plate width, plate edge parallelism and groove shape;

[0075] (III) Pre-bending: Use a pre-bending machine to pre-bend the edge of the composite steel plate after edge milling so that the inner diameter chord height within 150mm of the plate edge meets the inner diameter chord height of the corresponding pipe diameter to ensure the curvature of the pipe body;

[0076] (IV) Forming: The pre-bent composite steel plate is punched and bent using a JCOE forming machine to form a tube body with an opening in an "O" shape;

[0077] (V) Pre-welding: joining the above-formed pipe bodies and performing continuous welding;

[0078] (VI) Internal welding: the inner side of the pipe body is welded by submerged arc welding (welding conditions include: welding current of 500-1000A, welding voltage of 30-42V, welding speed of 1.35-1.7m / min); wherein the welding wire used obtains a weld structure mainly composed of pearlite after welding, so that the strength of the weld is equivalent to the strength of the anti-hydrogen permeation layer in the composite steel plate, for example, H08MnA welding wire can be used;

[0079] (VII) External welding: The outer side of the pipe body is welded by submerged arc welding (welding conditions include: welding current of 500-1000A, welding voltage of 30-42V, welding speed of 1.35-1.7m / min); wherein the welding wire used obtains a weld structure mainly composed of ferrite after welding, so that the strength of the weld is equivalent to the strength of the reinforcement layer in the composite steel plate, for example, H08MnMoTiB welding wire can be used;

[0080] (VIII) First ultrasonic continuous testing: inspect the inner and outer welds and both sides of the welds of the pipe body;

[0081] (IX) First X-ray TV inspection: X-ray industrial TV inspection of the inner and outer welds of the pipe body;

[0082] (X) Mechanical expansion: The entire length of the pipe is expanded to improve the dimensional accuracy of the pipe and the distribution of stress in the pipe;

[0083] (XI) Flat head: The two end faces of the tube body are machined to ensure the sealing effect of the subsequent water pressure test;

[0084] (XII) Hydrostatic test: Use a hydrostatic test machine to test the pipe body after mechanical expansion to ensure that it meets the allowable pressure required by the steel grade specified in GB / T9711;

[0085] (XIII) Chamfering: The pipe body that has passed the water pressure test is processed at the pipe end to achieve the target pipe end groove size;

[0086] (XIV) Second ultrasonic test: ultrasonic test is performed on the pipe body again to check for possible defects in the pipe body after mechanical expansion and water pressure test;

[0087] (XV) Second X-ray TV inspection: Filming or DR digital image extraction inspection of the weld area at the pipe end with a length of not less than 250 mm;

[0088] (XVI) Inspection of finished products.

[0089] According to the present invention, preferably, the inner diameter of the composite steel pipe may be 400-1500 mm.

[0090] According to the present invention, the tensile property loss rate of the composite steel pipe is less than 5%.

[0091] According to the present invention, the yield strength of the composite steel pipe is ≥435 MPa, and more preferably 500-625 MPa.

[0092] In the present invention, the tensile property loss rate and yield strength of the composite steel plate and composite steel pipe are determined according to the method specified in GB / T34542-2018.

[0093] The composite steel pipe provided by the present invention adopts a composite steel plate obtained by composite rolling of specific low-grade pipeline steel and high-grade pipeline steel as a pipe making material, which can well take into account both hydrogen embrittlement resistance and pipeline strength, can be used for large-volume, high-efficiency, long-distance and high-pressure transportation of hydrogen energy, and has a simple manufacturing process and is easy to implement.

[0094] The fifth aspect of the present invention provides application of the composite steel pipe described in the fourth aspect in the field of hydrogen energy transportation.

[0095] The present invention will be described in detail below by way of examples. In the following examples, unless otherwise specified, all materials used are common commercially available products.

[0096] Example 1

[0097] Preparation of composite steel plate:

[0098] (1-1) Pre-processing a first steel billet (material L290, thickness 15 mm) and a second steel billet (L485, thickness 80 mm), wherein the pre-processing includes cutting the first steel billet and the second steel billet into the same size and grinding the surfaces to be composited;

[0099] (1-2) contacting the surfaces of the first steel billet and the second steel billet to be composited after raw material pretreatment, so that the first steel billet and the second steel billet are completely overlapped and assembled into a blank to be welded, and then welding is performed to obtain a composite billet; wherein, a plurality of sheets are overlapped, two sheets of the first steel billet and the second steel billet are taken, and the four billets are overlapped from bottom to top in the order of "second steel billet→first steel billet→first steel billet→second steel billet", and during the overlapping process, a high temperature resistant isolation agent is injected between two adjacent first steel billets to prevent the two from being subsequently rolled together; vacuum electron beam welding is performed (welding conditions include: vacuum degree of 4.5×10 -2 Pa; welding current is 50mA, welding voltage is 50kV, welding speed is 0.6m / min), welding is performed along the contact line of the first steel billet and the second steel billet in the blank to be welded to achieve fixation;

[0100] (1-3) heating the composite blank to 1200°C and keeping the temperature for 4 hours, and then descaling;

[0101] (2-1) the dephosphorized composite billet is subjected to rough rolling (start rolling temperature is 1175-1225° C., and final rolling temperature is 885-915° C.) and finish rolling (start rolling temperature is 825-875° C., and final rolling temperature is 785-815° C.), and the rolled sheet is cooled and hot straightened to obtain a rolled product;

[0102] (2-2) The rolled piece is heated to 550° C. and kept at this temperature for 1 hour, and then the rolled piece is pre-cut and separated. The product size is preliminarily regulated by the pre-cut and separation. Due to the presence of the isolation agent, after the edges of the rolled piece are trimmed, the two groups of “first steel billet + second steel billet” are naturally separated to obtain two composite steel plate pre-products. The composite steel plate pre-products are then cold straightened and ultrasonically inspected to obtain a rough product.

[0103] (2-3) The rough product is sequentially subjected to fine shearing, fine straightening and surface treatment to obtain a composite steel plate (denoted as S1);

[0104] S1 has an anti-hydrogen permeation layer, and a reinforcement layer is arranged on one side of the anti-hydrogen permeation layer; wherein the thickness of the anti-hydrogen permeation layer is 3 mm, and the thickness of the reinforcement layer is 17.5 mm; the ratio of the yield strength of the anti-hydrogen permeation layer to the yield strength of the reinforcement layer is 1:1.6.

[0105] The tensile property loss rate of the composite steel plate S1 is 3.5%, and the yield strength is 500 MPa.

[0106] Preparation of composite pipe using composite steel plate S1:

[0107] (I) Ultrasonic plate detection: The composite steel plate S1 is subjected to full plate ultrasonic inspection to ensure that there is no excess Delamination defects of the equivalent size of flat bottom holes;

[0108] (II) Edge milling: The two edges of the composite steel plate are milled by an edge milling machine to achieve the target plate width, plate edge parallelism and groove shape;

[0109] (III) Pre-bending: Use a pre-bending machine to pre-bend the edge of the composite steel plate after edge milling so that the inner diameter chord height within 150mm of the plate edge meets the inner diameter chord height of the corresponding pipe diameter to ensure the curvature of the pipe body;

[0110] (IV) Forming: The pre-bent composite steel plate is punched and bent using a JCOE forming machine to form a tube body with an opening in an "O" shape;

[0111] (V) Pre-welding: joining the above-formed pipe bodies and performing continuous welding;

[0112] (VI) Internal welding: The inner side of the pipe body is welded by submerged arc welding (three welding wires are used, the welding current of the first welding wire is 850A, and the welding voltage is 32V; the welding current of the second welding wire is 600A, and the welding voltage is 36V; the welding current of the third welding wire is 500A, and the welding voltage is 38V; the welding speed is 1.5m / min); wherein, the three welding wires are all H08MnA welding wires, and after welding, a weld structure mainly composed of pearlite is obtained, so that the strength of the weld is equivalent to the strength of the hydrogen permeation resistance layer in the composite steel plate;

[0113] (VII) External welding: The outer side of the pipe body is welded by using a submerged arc welding process (four welding wires are used, the welding current of the first welding wire is 1000A, and the welding voltage is 32V; the welding current of the second welding wire is 850A, and the welding voltage is 36V; the welding current of the third welding wire is 600A, and the welding voltage is 38V; the welding current of the fourth welding wire is 500A, and the welding voltage is 40V; the welding speed is 1.6m / min); wherein, the four welding wires are all H08MnMoTiB welding wires, and after welding, a weld microstructure mainly composed of ferrite is obtained, so that the strength of the weld is equivalent to the strength of the reinforcement layer in the composite steel plate;

[0114] (VIII) First ultrasonic continuous testing: inspect the inner and outer welds and both sides of the welds of the pipe body;

[0115] (IX) First X-ray TV inspection: X-ray industrial TV inspection is carried out on the inner and outer welds of the pipe body. A single-wall single-shadow fixed X-ray equipment (with a DR flat panel device installed) is used to carry out 100% full weld radiographic inspection of the pipe body, mainly to find volume defects;

[0116] (X) Mechanical expansion: The entire length of the pipe is expanded to improve the dimensional accuracy of the pipe and the distribution of stress in the pipe;

[0117] (XI) Flat head: The two end faces of the tube body are machined to ensure the sealing effect of the subsequent water pressure test;

[0118] (XII) Hydrostatic test: Use a hydrostatic test machine to test the pipe body after mechanical expansion to ensure that it meets the allowable pressure required by the steel grade specified in GB / T9711;

[0119] (XIII) Chamfering: The pipe body that has passed the water pressure test is processed at the pipe end to achieve the target pipe end groove size;

[0120] (XIV) Second ultrasonic test: ultrasonic test is performed on the pipe body again to check for possible defects in the pipe body after mechanical expansion and water pressure test;

[0121] (XV) Second X-ray TV inspection: DR digital image extraction inspection of the weld area at the pipe end with a length of not less than 250 mm;

[0122] (XVI) Finished product inspection: a finished composite steel pipe (denoted as T1) is obtained.

[0123] The inner diameter of T1 is 780mm; the tensile performance loss rate of T1 is 3.5%, and the yield strength is 500MPa, which can meet the requirements of large-volume, high-efficiency, long-distance and high-pressure transportation of hydrogen energy.

[0124] Example 2

[0125] Preparation of composite steel plate:

[0126] (1-1) Pre-processing a first steel billet (material L290, thickness 15 mm) and a second steel billet (L555, thickness 80 mm), wherein the pre-processing includes cutting the first steel billet and the second steel billet into the same size and grinding the surfaces to be composited;

[0127] (1-2) contacting the surfaces of the first steel billet and the second steel billet to be composited after raw material pretreatment, so that the first steel billet and the second steel billet are completely overlapped and assembled into a blank to be welded, and then welding is performed to obtain a composite billet; wherein, a plurality of sheets are overlapped, two sheets of the first steel billet and the second steel billet are taken, and the four billets are overlapped from bottom to top in the order of "second steel billet→first steel billet→first steel billet→second steel billet", and during the overlapping process, a high temperature resistant isolation agent is injected between two adjacent first steel billets to prevent the two from being subsequently rolled together; vacuum electron beam welding is performed (welding conditions include: vacuum degree of 4.5×10 -2 Pa; welding current is 50mA, welding voltage is 50kV, welding speed is 0.6m / min), welding is performed along the contact line of the first steel billet and the second steel billet in the blank to be welded to achieve fixation;

[0128] (1-3) heating the composite blank to 1180°C and keeping the temperature for 4 hours, and then descaling;

[0129] (2-1) the dephosphorized composite billet is subjected to rough rolling (start rolling temperature is 1175-1225° C., and final rolling temperature is 885-915° C.) and finish rolling (start rolling temperature is 825-875° C., and final rolling temperature is 785-815° C.), and the rolled sheet is cooled and hot straightened to obtain a rolled product;

[0130] (2-2) The rolled piece is heated to 550° C. and kept at this temperature for 1 hour, and then the rolled piece is pre-cut and separated. The product size is preliminarily regulated by the pre-cut and separation. Due to the presence of the isolation agent, after the edges of the rolled piece are trimmed, the two groups of “first steel billet + second steel billet” are naturally separated to obtain two composite steel plate pre-products. The composite steel plate pre-products are then cold straightened and ultrasonically inspected to obtain a rough product.

[0131] (2-3) The rough product is sequentially subjected to fine shearing, fine straightening and surface treatment to obtain a composite steel plate (denoted as S2);

[0132] S2 has an anti-hydrogen permeation layer, and a reinforcement layer is arranged on one side of the anti-hydrogen permeation layer; wherein the thickness of the anti-hydrogen permeation layer is 3 mm, and the thickness of the reinforcement layer is 15 mm; the ratio of the yield strength of the anti-hydrogen permeation layer to the yield strength of the reinforcement layer is 1:1.66.

[0133] The tensile property loss rate of the composite steel plate S2 is 4%, and the yield strength is 550 MPa.

[0134] Preparation of composite pipe using composite steel plate S2:

[0135] (I) Ultrasonic plate detection: The composite steel plate S2 is subjected to full plate ultrasonic inspection to ensure that there is no excess Delamination defects of the equivalent size of flat bottom holes;

[0136] (II) Edge milling: The two edges of the composite steel plate are milled by an edge milling machine to achieve the target plate width, plate edge parallelism and groove shape;

[0137] (III) Pre-bending: Use a pre-bending machine to pre-bend the edge of the composite steel plate after edge milling so that the inner diameter chord height within 150mm of the plate edge meets the inner diameter chord height of the corresponding pipe diameter to ensure the curvature of the pipe body;

[0138] (IV) Forming: The pre-bent composite steel plate is punched and bent using a JCOE forming machine to form a tube body with an opening in an "O" shape;

[0139] (V) Pre-welding: joining the above-formed pipe bodies and performing continuous welding;

[0140] (VI) Internal welding: The inner side of the pipe body is welded by submerged arc welding (three welding wires are used, the welding current of the first welding wire is 850A, and the welding voltage is 32V; the welding current of the second welding wire is 600A, and the welding voltage is 36V; the welding current of the third welding wire is 500A, and the welding voltage is 38V; the welding speed is 1.5m / min); wherein, the three welding wires are all H08MnA welding wires, and after welding, a weld structure mainly composed of pearlite is obtained, so that the strength of the weld is equivalent to the strength of the hydrogen permeation resistance layer in the composite steel plate;

[0141] (VII) External welding: The outer side of the pipe body is welded by using a submerged arc welding process (four welding wires are used, the welding current of the first welding wire is 1000A, and the welding voltage is 32V; the welding current of the second welding wire is 850A, and the welding voltage is 36V; the welding current of the third welding wire is 600A, and the welding voltage is 38V; the welding current of the fourth welding wire is 500A, and the welding voltage is 40V; the welding speed is 1.6m / min); wherein, the four welding wires are all H08MnMoTiB welding wires, and after welding, a weld microstructure mainly composed of ferrite is obtained, so that the strength of the weld is equivalent to the strength of the reinforcement layer in the composite steel plate;

[0142] (VIII) First ultrasonic continuous testing: inspect the inner and outer welds and both sides of the welds of the pipe body;

[0143] (IX) First X-ray TV inspection: X-ray industrial TV inspection is carried out on the inner and outer welds of the pipe body. A single-wall single-shadow fixed X-ray equipment (with a DR flat panel device installed) is used to carry out 100% full weld radiographic inspection of the pipe body, mainly to find volume defects;

[0144] (X) Mechanical expansion: The entire length of the pipe is expanded to improve the dimensional accuracy of the pipe and the distribution of stress in the pipe;

[0145] (XI) Flat head: The two end faces of the tube body are machined to ensure the sealing effect of the subsequent water pressure test;

[0146] (XII) Hydrostatic test: Use a hydrostatic test machine to test the pipe body after mechanical expansion to ensure that it meets the allowable pressure required by the steel grade specified in GB / T9711;

[0147] (XIII) Chamfering: The pipe body that has passed the water pressure test is processed at the pipe end to achieve the target pipe end groove size;

[0148] (XIV) Second ultrasonic test: ultrasonic test is performed on the pipe body again to check for possible defects in the pipe body after mechanical expansion and water pressure test;

[0149] (XV) Second X-ray TV inspection: DR digital image extraction inspection of the weld area at the pipe end with a length of not less than 250 mm;

[0150] (XVI) Finished product inspection: a finished composite steel pipe (denoted as T2) is obtained.

[0151] The inner diameter of T2 is 980mm; the tensile performance loss rate of T2 is 4%, and the yield strength is 550MPa, which can meet the requirements of large-volume, high-efficiency, long-distance and high-pressure transportation of hydrogen energy.

[0152] Example 3

[0153] Preparation of composite steel plate:

[0154] (1-1) Pre-processing a first steel billet (material L360, thickness 15 mm) and a second steel billet (L485, thickness 80 mm), wherein the pre-processing includes cutting the first steel billet and the second steel billet into the same size and grinding the surfaces to be composited;

[0155] (1-2) contacting the surfaces of the first steel billet and the second steel billet to be composited after raw material pretreatment, so that the first steel billet and the second steel billet are completely overlapped and assembled into a blank to be welded, and then welding is performed to obtain a composite billet; wherein, a plurality of sheets are overlapped, two sheets of the first steel billet and the second steel billet are taken, and the four billets are overlapped from bottom to top in the order of "second steel billet→first steel billet→first steel billet→second steel billet", and during the overlapping process, a high temperature resistant isolation agent is injected between two adjacent first steel billets to prevent the two from being subsequently rolled together; vacuum electron beam welding is performed (welding conditions include: vacuum degree of 4.5×10 -2 Pa; welding current is 50mA, welding voltage is 50kV, welding speed is 0.6m / min), welding is performed along the contact line of the first steel billet and the second steel billet in the blank to be welded to achieve fixation;

[0156] (1-3) heating the composite blank to 1180°C and keeping the temperature for 4 hours, and then descaling;

[0157] (2-1) the dephosphorized composite billet is subjected to rough rolling (start rolling temperature is 1175-1225° C., and final rolling temperature is 885-915° C.) and finish rolling (start rolling temperature is 825-875° C., and final rolling temperature is 785-815° C.), and the rolled sheet is cooled and hot straightened to obtain a rolled product;

[0158] (2-2) The rolled piece is heated to 550° C. and kept at this temperature for 1 hour, and then the rolled piece is pre-cut and separated. The product size is preliminarily regulated by the pre-cut and separation. Due to the presence of the isolation agent, after the edges of the rolled piece are trimmed, the two groups of “first steel billet + second steel billet” are naturally separated to obtain two composite steel plate pre-products. The composite steel plate pre-products are then cold straightened and ultrasonically inspected to obtain a rough product.

[0159] (2-3) The rough product is sequentially subjected to fine shearing, fine straightening and surface treatment to obtain a composite steel plate (denoted as S3);

[0160] S3 has an anti-hydrogen permeation layer, and a reinforcement layer is arranged on one side of the anti-hydrogen permeation layer; wherein the thickness of the anti-hydrogen permeation layer is 4 mm, and the thickness of the reinforcement layer is 17 mm; the ratio of the yield strength of the anti-hydrogen permeation layer to the yield strength of the reinforcement layer is 1:1.5.

[0161] The tensile property loss rate of the composite steel plate S3 is 3.5%, and the yield strength is 500 MPa.

[0162] Preparation of composite pipe using composite steel plate S3:

[0163] (I) Ultrasonic plate detection: The composite steel plate S3 is subjected to full plate ultrasonic inspection to ensure that there is no excess Delamination defects of the equivalent size of flat bottom holes;

[0164] (II) Edge milling: The two edges of the composite steel plate are milled by an edge milling machine to achieve the target plate width, plate edge parallelism and groove shape;

[0165] (III) Pre-bending: Use a pre-bending machine to pre-bend the edge of the composite steel plate after edge milling so that the inner diameter chord height within 150mm of the plate edge meets the inner diameter chord height of the corresponding pipe diameter to ensure the curvature of the pipe body;

[0166] (IV) Forming: The pre-bent composite steel plate is punched and bent using a JCOE forming machine to form a tube body with an opening in an "O" shape;

[0167] (V) Pre-welding: joining the above-formed pipe bodies and performing continuous welding;

[0168] (VI) Internal welding: The inner side of the pipe body is welded by submerged arc welding (three welding wires are used, the welding current of the first welding wire is 850A, and the welding voltage is 32V; the welding current of the second welding wire is 600A, and the welding voltage is 36V; the welding current of the third welding wire is 500A, and the welding voltage is 38V; the welding speed is 1.5m / min); wherein, the three welding wires are all H08MnA welding wires, and after welding, a weld structure mainly composed of pearlite is obtained, so that the strength of the weld is equivalent to the strength of the hydrogen permeation resistance layer in the composite steel plate;

[0169] (VII) External welding: The outer side of the pipe body is welded by using a submerged arc welding process (four welding wires are used, the welding current of the first welding wire is 1000A, and the welding voltage is 32V; the welding current of the second welding wire is 850A, and the welding voltage is 36V; the welding current of the third welding wire is 600A, and the welding voltage is 38V; the welding current of the fourth welding wire is 500A, and the welding voltage is 40V; the welding speed is 1.6m / min); wherein, the four welding wires are all H08MnMoTiB welding wires, and after welding, a weld microstructure mainly composed of ferrite is obtained, so that the strength of the weld is equivalent to the strength of the reinforcement layer in the composite steel plate;

[0170] (VIII) First ultrasonic continuous testing: inspect the inner and outer welds and both sides of the welds of the pipe body;

[0171] (IX) First X-ray TV inspection: X-ray industrial TV inspection is carried out on the inner and outer welds of the pipe body. A single-wall single-shadow fixed X-ray equipment (with a DR flat panel device installed) is used to carry out 100% full weld radiographic inspection of the pipe body, mainly to find volume defects;

[0172] (X) Mechanical expansion: The entire length of the pipe is expanded to improve the dimensional accuracy of the pipe and the distribution of stress in the pipe;

[0173] (XI) Flat head: The two end faces of the tube body are machined to ensure the sealing effect of the subsequent water pressure test;

[0174] (XII) Hydrostatic test: Use a hydrostatic test machine to test the pipe body after mechanical expansion to ensure that it meets the allowable pressure required by the steel grade specified in GB / T9711;

[0175] (XIII) Chamfering: The pipe body that has passed the water pressure test is processed at the pipe end to achieve the target pipe end groove size;

[0176] (XIV) Second ultrasonic test: ultrasonic test is performed on the pipe body again to check for possible defects in the pipe body after mechanical expansion and water pressure test;

[0177] (XV) Second X-ray TV inspection: DR digital image extraction inspection of the weld area at the pipe end with a length of not less than 250 mm;

[0178] (XVI) Finished product inspection: a finished composite steel pipe (denoted as T3) is obtained.

[0179] The inner diameter of T3 is 980mm; the tensile performance loss rate of T3 is 3.5%, and the yield strength is 500MPa, which can meet the requirements of large-volume, high-efficiency, long-distance and high-pressure transportation of hydrogen energy.

[0180] Example 4

[0181] Preparation of composite steel plate:

[0182] (1-1) Pre-processing a first steel billet (material L360, thickness 15 mm) and a second steel billet (L555, thickness 80 mm), wherein the pre-processing includes cutting the first steel billet and the second steel billet into the same size and grinding the surfaces to be composited;

[0183] (1-2) contacting the surfaces of the first steel billet and the second steel billet to be composited after raw material pretreatment, so that the first steel billet and the second steel billet are completely overlapped and assembled into a blank to be welded, and then welding is performed to obtain a composite billet; wherein, a plurality of sheets are overlapped, two sheets of the first steel billet and the second steel billet are taken, and the four billets are overlapped from bottom to top in the order of "second steel billet→first steel billet→first steel billet→second steel billet", and during the overlapping process, a high temperature resistant isolation agent is injected between two adjacent first steel billets to prevent the two from being subsequently rolled together; vacuum electron beam welding is performed (welding conditions include: vacuum degree of 4.5×10 -2 Pa; welding current is 50mA, welding voltage is 50kV, welding speed is 0.6m / min), welding is performed along the contact line of the first steel billet and the second steel billet in the blank to be welded to achieve fixation;

[0184] (1-3) heating the composite blank to 1180°C and keeping the temperature for 4 hours, and then descaling;

[0185] (2-1) the dephosphorized composite billet is subjected to rough rolling (start rolling temperature is 1175-1225° C., and final rolling temperature is 885-915° C.) and finish rolling (start rolling temperature is 825-875° C., and final rolling temperature is 785-815° C.), and the rolled sheet is cooled and hot straightened to obtain a rolled product;

[0186] (2-2) The rolled piece is heated to 550° C. and kept at this temperature for 1 hour, and then the rolled piece is pre-cut and separated. The product size is preliminarily regulated by the pre-cut and separation. Due to the presence of the isolation agent, after the edges of the rolled piece are trimmed, the two groups of “first steel billet + second steel billet” are naturally separated to obtain two composite steel plate pre-products. The composite steel plate pre-products are then cold straightened and ultrasonically inspected to obtain a rough product.

[0187] (2-3) The rough product is sequentially subjected to fine shearing, fine straightening and surface treatment to obtain a composite steel plate (denoted as S4);

[0188] S4 has an anti-hydrogen permeation layer, and a reinforcement layer is arranged on one side of the anti-hydrogen permeation layer; wherein the thickness of the anti-hydrogen permeation layer is 4 mm, and the thickness of the reinforcement layer is 18 mm; the ratio of the yield strength of the anti-hydrogen permeation layer to the yield strength of the reinforcement layer is 1:1.53.

[0189] The tensile property loss rate of the composite steel plate S4 is 4%, and the yield strength is 550 MPa.

[0190] Preparation of composite pipe using composite steel plate S4:

[0191] (I) Ultrasonic plate detection: The composite steel plate S4 is subjected to full plate ultrasonic inspection to ensure that there is no excess Delamination defects of the equivalent size of flat bottom holes;

[0192] (II) Edge milling: The two edges of the composite steel plate are milled by an edge milling machine to achieve the target plate width, plate edge parallelism and groove shape;

[0193] (III) Pre-bending: Use a pre-bending machine to pre-bend the edge of the composite steel plate after edge milling so that the inner diameter chord height within 150mm of the plate edge meets the inner diameter chord height of the corresponding pipe diameter to ensure the curvature of the pipe body;

[0194] (IV) Forming: The pre-bent composite steel plate is punched and bent using a JCOE forming machine to form a tube body with an opening in an "O" shape;

[0195] (V) Pre-welding: joining the above-formed pipe bodies and performing continuous welding;

[0196] (VI) Internal welding: The inner side of the pipe body is welded by submerged arc welding (three welding wires are used, the welding current of the first welding wire is 850A, and the welding voltage is 32V; the welding current of the second welding wire is 600A, and the welding voltage is 36V; the welding current of the third welding wire is 500A, and the welding voltage is 38V; the welding speed is 1.5m / min); wherein, the three welding wires are all H08MnA welding wires, and after welding, a weld structure mainly composed of pearlite is obtained, so that the strength of the weld is equivalent to the strength of the hydrogen permeation resistance layer in the composite steel plate;

[0197] (VII) External welding: The outer side of the pipe body is welded by using a submerged arc welding process (four welding wires are used, the welding current of the first welding wire is 1000A, and the welding voltage is 32V; the welding current of the second welding wire is 850A, and the welding voltage is 36V; the welding current of the third welding wire is 600A, and the welding voltage is 38V; the welding current of the fourth welding wire is 500A, and the welding voltage is 40V; the welding speed is 1.6m / min); wherein, the four welding wires are all H08MnMoTiB welding wires, and after welding, a weld microstructure mainly composed of ferrite is obtained, so that the strength of the weld is equivalent to the strength of the reinforcement layer in the composite steel plate;

[0198] (VIII) First ultrasonic continuous testing: inspect the inner and outer welds and both sides of the welds of the pipe body;

[0199] (IX) First X-ray TV inspection: X-ray industrial TV inspection is carried out on the inner and outer welds of the pipe body. A single-wall single-shadow fixed X-ray equipment (with a DR flat panel device installed) is used to carry out 100% full weld radiographic inspection of the pipe body, mainly to find volume defects;

[0200] (X) Mechanical expansion: The entire length of the pipe is expanded to improve the dimensional accuracy of the pipe and the distribution of stress in the pipe;

[0201] (XI) Flat head: The two end faces of the tube body are machined to ensure the sealing effect of the subsequent water pressure test;

[0202] (XII) Hydrostatic test: Use a hydrostatic test machine to test the pipe body after mechanical expansion to ensure that it meets the allowable pressure required by the steel grade specified in GB / T9711;

[0203] (XIII) Chamfering: The pipe body that has passed the water pressure test is processed at the pipe end to achieve the target pipe end groove size;

[0204] (XIV) Second ultrasonic test: ultrasonic test is performed on the pipe body again to check for possible defects in the pipe body after mechanical expansion and water pressure test;

[0205] (XV) Second X-ray TV inspection: DR digital image extraction inspection of the weld area at the pipe end with a length of not less than 250 mm;

[0206] (XVI) Finished product inspection: a finished composite steel pipe (denoted as T4) is obtained.

[0207] The inner diameter of T4 is 980mm; the tensile performance loss rate of T4 is 4%, and the yield strength is 550MPa, which can meet the requirements of large-volume, high-efficiency, long-distance and high-pressure transportation of hydrogen energy.

[0208] Comparative Example 1

[0209] Preparation of composite steel plate:

[0210] The composite steel plate was prepared according to the method of Example 1, except that the second steel billet in step (1-1) was L290 pipeline steel with a thickness of 80 mm. Other conditions and parameters were the same as those of Example 1. A composite steel plate (denoted as DS1) was obtained;

[0211] DS1 has an anti-hydrogen permeation layer, and a reinforcement layer is arranged on one side of the anti-hydrogen permeation layer; wherein the thickness of the anti-hydrogen permeation layer is 3 mm, and the thickness of the reinforcement layer is 17.5 mm; the ratio of the yield strength of the anti-hydrogen permeation layer to the yield strength of the reinforcement layer is 1:1.

[0212] The tensile property loss rate of the composite steel plate DS1 is 3%, and the yield strength is 280 MPa.

[0213] A composite pipe was prepared using the composite steel plate DS1 according to the method and parameters of Example 1 to obtain a composite steel pipe product (denoted as DT1).

[0214] The inner diameter of DT1 is 780mm; the tensile performance loss rate of DT1 is 3%, and the yield strength is 280MPa, which cannot meet the requirements of large-volume, high-efficiency, long-distance and high-pressure transportation of hydrogen energy.

[0215] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A composite steel plate, characterized in that: The composite steel plate comprises a hydrogen permeation resistant layer and a reinforcement layer disposed on one side of the hydrogen permeation resistant layer; The material of the hydrogen permeation resistant layer and the reinforcement layer is pipeline steel, and the ratio of the yield strength of the hydrogen permeation resistant layer to the yield strength of the reinforcement layer is 1:(1.5-1.7).

2. The composite steel plate according to claim 1, wherein: The hydrogen permeation resistant layer is selected from at least one of L290 pipeline steel, L320 pipeline steel, L360 pipeline steel and L390 pipeline steel; And / or, the reinforcement layer is selected from L485 pipeline steel and / or L555 pipeline steel.

3. The composite steel plate according to claim 1 or 2, wherein: The thickness of the anti-hydrogen permeation layer is 3-5 mm, preferably 3.5-4.5 mm; And / or, the thickness of the reinforcement layer is 10-30 mm, preferably 16.5-17.5 mm.

4. A method for preparing a composite steel plate, comprising: (1) superimposing and welding a first steel billet and a second steel billet to obtain a composite billet; (2) rolling and cutting the composite billet to obtain a composite steel plate; Wherein, the first steel billet and the second steel billet are made of pipeline steel; In the composite steel plate, the yield strength ratio of the hydrogen permeation resistant layer formed by the first steel billet to the reinforcing layer formed by the second steel billet is 1:(1.5-1.7).

5. The method according to claim 4, wherein: The material of the first steel billet is selected from at least one of L290 pipeline steel, L320 pipeline steel, L360 pipeline steel and L390 pipeline steel; And / or, the material of the second steel billet is selected from L485 pipeline steel and / or L555 pipeline steel.

6. The method according to claim 4 or 5, wherein: The thickness of the anti-hydrogen permeation layer is 3-5 mm; And / or, the thickness of the reinforcement layer is 10-30 mm.

7. The method according to any one of claims 4 to 6, wherein: The welding adopts vacuum electron beam welding; Preferably, the vacuum electron beam welding conditions include: vacuum degree ≤ 5×10 -2 Pa; welding current is 20-60mA, welding voltage is 40-60kV, and welding speed is 0.6-1.2m / min.

8. The method according to any one of claims 4 to 7, wherein: The rolling includes rough rolling and finish rolling; The starting rolling temperature of the rough rolling is 1175-1225°C, and the final rolling temperature is 885-915°C; The start rolling temperature of the finish rolling is 825-875°C, and the final rolling temperature is 785-815°C.

9. A composite steel plate obtained by the method according to any one of claims 4 to 8.

10. A composite steel pipe, obtained by forming and welding the composite steel plate according to any one of claims 1 to 3 and 9; in, The inner wall of the composite steel pipe is the anti-hydrogen permeation layer of the composite steel plate, and the outer wall of the composite steel pipe is the reinforcement layer of the composite steel plate.

11. The composite steel pipe according to claim 10, wherein: The inner diameter of the composite steel pipe is 400-1500 mm.

12. The composite steel pipe according to claim 10 or 11, wherein: The tensile performance loss rate of the composite steel pipe is less than 5%; Preferably, the yield strength of the composite steel pipe is ≥435 MPa, more preferably 500-625 MPa.

13. Use of the composite steel pipe according to any one of claims 10 to 12 in the field of hydrogen energy transportation.

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