A symmetrical blanking method for producing stainless steel clad plate by vacuum electron beam welding

Abstract

The present application relates to the technical field of metallurgy, and particularly relates to a symmetrical blanking method for producing stainless steel composite plate by vacuum electron beam welding, which comprises the following steps: selecting raw materials of stainless steel plate, carbon steel plate and L-shaped steel blank; milling the carbon steel plate to obtain a carbon steel base plate; stacking the stainless steel plate on the carbon steel base plate and performing vacuum sealing welding to obtain a single-sided composite blank; combining the L-shaped steel blanks; placing one single-sided composite blank with the stainless steel surface upward, placing two L-shaped steel blanks to form a "U" shaped outer frame, then brushing isolating agent, and finally stacking another single-sided composite blank with the stainless steel surface downward to form a to-be-welded stacked blank; welding the to-be-welded stacked blank; performing rolling and cooling; and cutting and separating to obtain two metal composite plate products of the same specification. The present application omits the processes of post-welding evacuation and drying of isolating agent and related equipment, can reduce production cost, improve production efficiency, and improve the internal quality of the stainless steel composite plate.

Description

Technical Field

[0001] This invention relates to the field of metallurgical technology, specifically to a symmetrical preform preparation method for producing stainless steel composite plates using vacuum electron beam welding. Background Technology

[0002] Metal composite plates are sheets made by metallurgically bonding metals with different properties at the interface. Compared to single metal materials, they can greatly improve and enhance properties such as thermal expansion, strength, toughness, wear resistance, and corrosion resistance, while saving on the amount of precious metals used and reducing material costs. Therefore, they are widely used in various industrial fields. Stainless steel composite plates are metal composite plates made by bonding a carbon steel base layer with a stainless steel cladding layer. They possess both the corrosion resistance of stainless steel and the good mechanical strength and processing performance of carbon steel, and have been successfully applied in industries such as petroleum, chemical, salt, and water conservancy and power.

[0003] In the preparation of stainless steel composite plates, due to the different materials and expansion coefficients of the carbon steel base layer and the stainless steel cladding, single-sided rolling is prone to warping and other problems, causing significant impact on the rolling mill, resulting in an unstable and difficult-to-control rolling process, and requiring extremely high precision in heating and rolling techniques. Therefore, existing technologies widely employ a symmetrical billet preparation method. To prevent adhesion between the stainless steel layers, a release agent is uniformly applied to the stainless steel surface before billet preparation. The stainless steel with the release agent is then dried as a whole. Next, carbon steel and stainless steel plates are stacked in a carbon steel-stainless steel-stainless steel-carbon steel stacking manner. Finally, the billet is welded around its perimeter using submerged arc welding, and a vacuum is applied after welding to obtain the composite billet. After rolling, the two layers are separated to obtain two stainless steel composite plates. Current technologies require uniformly applying a release agent to the stainless steel surface before drying. This drying process necessitates the use of a drying oven, resulting in high costs, long drying times, and low production efficiency. Furthermore, existing technologies often employ submerged arc welding followed by post-weld vacuum pumping to produce composite billets. However, submerged arc welding consumes large amounts of welding wire and flux, leading to high production costs. Additionally, using a mechanical pump to vacuum the post-weld composite billet makes it difficult to reduce the vacuum level between the stainless steel and carbon steel plates to 1.0*10. -2 As a result, the stainless steel composite plates produced are prone to internal quality fluctuations and low production efficiency. Summary of the Invention

[0004] To address the technical problems of existing symmetrical preform production processes using submerged arc welding followed by post-weld mechanical pump vacuuming for single-sided composite plates, such as difficulty in controlling low vacuum levels, high consumption of welding wire and flux, high production costs, and susceptibility to quality fluctuations, as well as the need for drying the release agent and low production efficiency, this invention provides a symmetrical preform production method for stainless steel composite plates using vacuum electron beam welding. This method involves vacuum sealing of stainless steel and carbon steel plates, saving welding materials, eliminating the need for post-weld vacuuming, improving production efficiency, and enhancing the internal quality of the stainless steel composite plate. Furthermore, the absence of drying after applying the release agent eliminates the need for drying the release agent and related equipment, further improving production efficiency and reducing production costs.

[0005] The technical solution of this invention is as follows:

[0006] A symmetrical preform preparation method for producing stainless steel composite plates using vacuum electron beam welding includes the following steps:

[0007] (1) Material preparation: Select two stainless steel plates and two carbon steel plates of the same specifications according to the specifications of the required metal composite plate products. The length and width of the carbon steel plates are greater than those of the stainless steel plates. Select two longitudinal plain carbon steel strips and two transverse plain carbon steel strips of the same specifications. The length of the longitudinal plain carbon steel strips is the same as the length of the carbon steel plates. The width of the longitudinal plain carbon steel strips is 1 / 2 the difference between the width of the carbon steel plates and the width of the stainless steel plates. The thickness is greater than twice the thickness of the stainless steel plates and less than twice the sum of the thickness of the stainless steel plates and the thickness of the carbon steel plates. The length of the transverse plain carbon steel strips is the same as the width of the stainless steel plates. The width of the transverse plain carbon steel strips is 1 / 2 the difference between the length of the carbon steel plates and the length of the stainless steel plates. The thickness is the same as the thickness of the longitudinal plain carbon steel strips.

[0008] (2) Milling carbon steel: Milling the four sides of the top surface of each carbon steel plate with a uniform depth that is symmetrical in both length and width directions. The milling depth is 1 / 2 of the thickness of the ordinary carbon steel strip and the difference between the thickness of the stainless steel plate, thus producing a carbon steel substrate. A bonding plane is formed at the center of the top surface of the carbon steel substrate. The bonding plane is a rectangle with the same length and width as the stainless steel plate.

[0009] Since vacuum electron beam welding machines are difficult to use for vacuum electron beam welding of T-joints, the top of the carbon steel plate is milled. After milling, the stainless steel plate can be stacked on the mating plane on the top of the carbon steel plate, and the edge of the stainless steel plate can be strictly aligned with the edge of the mating plane to form a butt weld joint with an included angle of 180°, which facilitates vacuum electron beam welding.

[0010] (3) First sealing weld: A stainless steel plate is stacked on the joint plane of a carbon steel substrate. The edges of the stainless steel plate and the joint plane are strictly aligned. Then, it is sent into a vacuum electron beam welding machine to vacuum seal the joint between the stainless steel plate and the joint plane to obtain a single-sided composite blank with a cuboid protrusion in the center. Repeat the above operation to obtain two single-sided composite blanks of the same specifications.

[0011] Vacuum sealing welding of stacked stainless steel and carbon steel plates can ensure that there is a vacuum between the stainless steel plate and the bonding surface, ensuring that air will not enter during the rolling process, which will lead to insufficient fusion between stainless steel and carbon steel, avoid problems such as delamination and bubbles, and improve the internal quality of stainless steel composite plates.

[0012] (4) Assemble the L-shaped steel billets by vertically welding a transverse plain carbon steel bar to the side of a longitudinal plain carbon steel bar, so that the length direction of the transverse plain carbon steel bar is perpendicular to the length direction of the longitudinal plain carbon steel bar, and the thickness direction of the transverse plain carbon steel bar is the same as the thickness direction of the longitudinal plain carbon steel bar, to form an L-shaped steel billet with the same thickness; repeat the above operation to obtain two L-shaped steel billets.

[0013] (5) Assemble the stacked blanks to be welded. Place a single-sided composite blank horizontally with the stainless steel side facing up. Place two L-shaped steel blanks on each blank, so that the corners of the two L-shaped steel blanks are located on the outside of the two diagonal corners of the cuboid protrusion on the top surface of the single-sided composite blank. The long side of each L-shaped steel blank is in contact with one long side of the single-sided composite blank, and the short side of each L-shaped steel blank is in contact with one short side of the single-sided composite blank. The two L-shaped steel blanks are combined to form a "U" shaped outer frame. Then, apply a release agent evenly to the stainless steel surface of the single-sided composite blank to form a release layer. Finally, stack another single-sided composite blank with the stainless steel side facing down, so that the stainless steel surfaces of the two single-sided composite blanks are strictly aligned, the inner side of the L-shaped steel blank is in close contact with the cuboid protrusion of the single-sided composite blank, and the outer side of the L-shaped steel blank is flush with the outer side of the single-sided composite blank to form a cuboid stacked blank to be welded.

[0014] Two L-shaped steel billets are sandwiched between two opposing single-sided composite billets. The contact area between the two L-shaped steel billets is not welded, and the resulting gap is equivalent to two pre-reserved vent holes. The gas generated by the release agent during heating can be discharged through the gap between the two L-shaped steel billets, thereby avoiding excessive gas residue between the two single-sided composite billets and the occurrence of phenomena such as "bulging". Therefore, there is no need to dry the release agent separately, which improves production efficiency.

[0015] (6) Second sealing welding: The stacked blanks to be welded are sent into a vacuum electron beam welding machine to weld the joints of the L-shaped steel blanks and the upper and lower single-sided composite blanks respectively to obtain the composite blanks.

[0016] (7) Rolling: The composite billet is heated and then fed into a rolling mill for rolling and cooling to obtain a composite steel plate;

[0017] (8) Cutting and separating: Cut the four sides of the composite steel plate and remove the part containing plain carbon steel. The steel plate will naturally separate to obtain two metal composite plate products of the same specifications.

[0018] Furthermore, the length of the carbon steel plate is 50-200mm longer than that of the stainless steel plate, the width of the carbon steel plate is 50-200mm wider than that of the stainless steel plate, and the thickness of the longitudinal plain carbon steel strip is twice the thickness of the stainless steel plate plus 40-100mm.

[0019] Furthermore, in step (3), the surface of the stainless steel plate and the mating plane are first polished to remove all the iron oxide scale on the stainless steel plate and the mating plane, and then stacked and vacuum sealed.

[0020] Furthermore, in step (3), after the stainless steel plate is strictly aligned with the edge of the mating plane, the gap width at the joint between the stainless steel plate and the mating plane is ≤0.4mm.

[0021] Furthermore, in step (3), the gas pressure is controlled to be ≤1.0*10 inside the vacuum electron beam welder. -2 Pa is used for sealing; in step (6), the gas pressure is controlled to be ≤1.0*10 in the vacuum electron beam welding machine. -2 Pa is used for sealing.

[0022] Furthermore, after vacuum sealing in step (3), the penetration depth of the single-sided composite blank welded joint is tested to ensure that the penetration depth is ≥10mm; if the penetration depth is >10mm, the single-sided composite blank is sent back into the vacuum electron beam welder for vacuum sealing until the penetration depth is ≥10mm.

[0023] Furthermore, the thickness of the isolation layer in step (5) is 0.5~1.0 mm.

[0024] Furthermore, after welding in step (6), the weld depth of the composite billet is tested to ensure that the weld depth is ≥30mm; if the weld depth is <30mm, the single-sided composite billet is sent back into the vacuum electron beam welding machine for vacuum sealing until the weld depth is ≥30mm.

[0025] Beneficial effects

[0026] The beneficial effects of this invention are as follows:

[0027] 1. The symmetrical billet preparation method for producing stainless steel composite plates using vacuum electron beam welding provided by the present invention performs vacuum sealing welding on stainless steel plates and carbon steel plates in a vacuum electron beam welding machine. After welding, there is no need to perform vacuuming treatment on the billet to ensure that the stainless steel plate and the bonding surface are in a vacuum state. This saves the post-weld vacuuming process and avoids quality problems caused by air between the stainless steel plate and the carbon steel plate or air entering during the rolling process, thereby improving production efficiency and improving the internal quality of stainless steel composite plates.

[0028] 2. This invention uses a symmetrical blanking process to produce stainless steel composite plates. After uniformly applying the release agent between two opposite single-sided composite blanks, there is no need to dry the release agent, which saves the process and related equipment for drying the release agent, further improving production efficiency and reducing production costs.

[0029] 3. The present invention uses a vacuum electron beam welding machine for vacuum sealing, which can fully and uniformly weld stainless steel plates and carbon steel plates, as well as carbon steel plates and L-shaped steel billets, without the need for additional welding wire and flux. The welding process does not introduce impurities, the welding quality is good, and welding materials such as welding wire and flux are saved.

[0030] 4. This invention is simple to operate. It optimizes the production process, improves production efficiency, and reduces production costs based on the traditional stainless steel composite plate blanking process. It can obtain stainless steel composite plates with high composite strength and good internal quality with a lower production cost and in combination with traditional rolling process. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the structure of the single-sided composite blank in Example 1.

[0033] Figure 2 This is a schematic diagram of the L-shaped steel billet in Example 1.

[0034] Figure 3 This is a cross-sectional view of the composite blank in Example 1.

[0035] Figure 4 This is a horizontal cross-sectional view of the composite billet in Example 1.

[0036] In the diagram, 1-carbon steel substrate, 2-stainless steel plate, 3-L-shaped steel billet. Detailed Implementation

[0037] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0038] Example 1

[0039] A symmetrical preform preparation method for producing stainless steel composite plates using vacuum electron beam welding, wherein the target size of the stainless steel composite plate is 15*1220*12000mm, includes the following steps:

[0040] (1) Material preparation: Select two stainless steel plates with a specification of 12*1220*2440mm and two carbon steel plates with a specification of 75*1320*2540mm; select two longitudinal plain carbon steel bars with a specification of 64*50*2540mm and two transverse plain carbon steel bars with a specification of 64*50*1220mm;

[0041] (2) Milling carbon steel: Milling the four sides of the top surface of each carbon steel plate with a uniform depth symmetrical in both length and width directions. The milling depth is 20mm to obtain carbon steel substrate 1. A rectangular joint plane is formed at the center of the top surface of carbon steel substrate 1. The dimensions of the joint plane are 1220*2440mm, which are the same as the length and width of the stainless steel plate.

[0042] (3) For the first sealing weld, the surfaces of the carbon steel substrate 1 and the stainless steel plate 2 are first ground to remove all the iron oxide scale on the surfaces of the carbon steel substrate 1 and the stainless steel plate 2. Then, a stainless steel plate 2 is stacked on the joint plane of a carbon steel substrate 1. The edges of the stainless steel plate 2 and the joint plane are strictly aligned. After alignment, the gap width at the joint of the stainless steel plate 2 and the joint plane is ≤0.4mm. Then, it is sent into the vacuum electron beam welding machine to perform vacuum sealing weld on the joint between the stainless steel plate 2 and the joint plane to obtain a single-sided composite blank with a cuboid protrusion in the center. Then, the penetration depth of the welded part of the single-sided composite blank is tested to ensure that the penetration depth is ≥10mm. If the penetration depth is <10mm, the single-sided composite blank is sent back into the vacuum electron beam welding machine for vacuum sealing weld until the penetration depth is ≥10mm. Repeat the above operation to obtain two single-sided composite blanks of the same specifications.

[0043] (4) Assemble the L-shaped steel billets by vertically welding a transverse plain carbon steel bar to the side of a longitudinal plain carbon steel bar, so that the length direction of the transverse plain carbon steel bar is perpendicular to the length direction of the longitudinal plain carbon steel bar, and the thickness direction of the transverse plain carbon steel bar is the same as the thickness direction of the longitudinal plain carbon steel bar, to form an L-shaped steel billet 3 with the same thickness; repeat the above operation to obtain two L-shaped steel billets 3.

[0044] (5) Assemble the stacked blanks to be welded. Place a single-sided composite blank horizontally with the stainless steel side facing up. Place two L-shaped steel blanks 3 on each blank, so that the corners of the two L-shaped steel blanks 3 are located on the outside of the two diagonal corners of the cuboid protrusion on the top surface of the single-sided composite blank. The long side of each L-shaped steel blank is in contact with one long side of the single-sided composite blank, and the short side of each L-shaped steel blank is in contact with one short side of the single-sided composite blank. The two L-shaped steel blanks are combined to form a "U" shaped outer frame. Then, apply a release agent evenly to the stainless steel surface of the single-sided composite blank to form a release layer with a thickness of 0.5 mm. Finally, stack another single-sided composite blank with the stainless steel side facing down, so that the stainless steel surfaces of the two single-sided composite blanks are strictly aligned, the inner side of the L-shaped steel blank 3 is in close contact with the cuboid protrusion of the single-sided composite blank, and the outer side of the L-shaped steel blank 3 is flush with the outer side of the single-sided composite blank to form a cuboid stacked blank to be welded.

[0045] (6) Second sealing welding: The stacked blanks to be welded are sent into the vacuum electron beam welding machine, and the joints of the L-shaped steel blank 3 and the upper and lower single-sided composite blanks are welded to obtain the composite blank. After welding, the penetration depth of the welded part of the composite blank is tested to ensure that the penetration depth is ≥30mm. If the penetration depth is <30mm, the composite blank is sent back into the vacuum electron beam welding machine for vacuum sealing welding until the penetration depth is ≥30mm. The size of the composite blank is 174*1320*2540mm.

[0046] (7) Rolling: After heating the composite billet, it is fed into the rolling mill for rolling and cooling to produce a composite steel plate with a specification of 30*1320*14500mm.

[0047] (8) Cutting and separating: Cut the four sides of the composite steel plate and remove the part containing ordinary carbon steel. The steel plate will separate naturally to obtain two metal composite plate products with a specification of 15*1220*12000mm.

[0048] Although the present invention has been described in detail with reference to the accompanying drawings and preferred embodiments, the present invention is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the present invention by those skilled in the art without departing from the spirit and essence of the invention, and such modifications or substitutions should all be within the scope of the present invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should also be covered within the protection scope of the present invention.

Claims

1. A symmetrical preform preparation method for producing stainless steel composite plates using vacuum electron beam welding, characterized in that, It includes the following steps: It includes the following steps: (1) Select two stainless steel plates and two carbon steel plates of the same specification according to the specification of the required metal composite plate product. The length and width of the carbon steel plates are both greater than those of the stainless steel plates. Select two longitudinal common carbon steel bars and two transverse common carbon steel bars of the same specification. The length of the longitudinal common carbon steel bar is the same as the length of the carbon steel plate. The width of the longitudinal common carbon steel bar is 1 / 2 of the difference between the width of the carbon steel plate and the width of the stainless steel plate, and the thickness is greater than twice the thickness of the stainless steel plate and less than twice the sum of the thickness of the stainless steel plate and the thickness of the carbon steel plate. The length of the transverse common carbon steel bar is the same as the width of the stainless steel plate. The width of the transverse common carbon steel bar is 1 / 2 of the difference between the length of the carbon steel plate and the length of the stainless steel plate, and the thickness is the same as the thickness of the longitudinal common carbon steel bar; The length of the carbon steel plate is 50 - 200 mm more than the length of the stainless steel plate, the width of the carbon steel plate is 50 - 200 mm more than the width of the stainless steel plate, and the thickness of the longitudinal common carbon steel bar is 2 times the thickness of the stainless steel plate + 40 - 100 mm; (2) Perform milling on the four sides of the top surface of each carbon steel plate symmetrically along the length direction and the width direction with uniform depth. The milling depth is the difference between 1 / 2 of the thickness of the common carbon steel bar and the thickness of the stainless steel plate, and a carbon steel substrate is obtained. A bonding plane is formed at the center of the top surface of the carbon steel substrate, and the bonding plane is a rectangle with the same length and width as the stainless steel plate; (3) A stainless steel plate is stacked on the mating plane of a carbon steel substrate, with the edges of the stainless steel plate and the mating plane strictly aligned. Then, it is fed into a vacuum electron beam welding machine to vacuum seal the joint between the stainless steel plate and the mating plane. Specifically, the gas pressure in the vacuum electron beam welding machine is controlled to be ≤1.0*10. -2 Pa performs sealing welding to obtain a single-sided composite blank with a cuboid protrusion in the center; repeat the above operation to obtain two single-sided composite blanks of the same specifications. (4)Vertically weld a transverse common carbon steel bar to the side of a longitudinal common carbon steel bar, so that the length direction of the transverse common carbon steel bar is perpendicular to the length direction of the longitudinal common carbon steel bar, and the thickness direction of the transverse common carbon steel bar is the same as the thickness direction of the longitudinal common carbon steel bar, forming an L-shaped billet with uniform thickness; Repeat the above operation to obtain two L-shaped billets; (5)Horizontally place a single-sided composite blank with the stainless steel surface facing up, and place two L-shaped billets respectively, so that the corners of the two L-shaped billets are located outside the two diagonal corners of the cuboid protrusion on the top surface of the single-sided composite blank, and the long side of each L-shaped billet is fitted to one long side of the single-sided composite blank, and the short side of each L-shaped billet is fitted to one short side of the single-sided composite blank. The two L-shaped billets are combined into a "return" - shaped outer frame; Then evenly apply a release agent on the stainless steel surface of the single-sided composite blank to form a release layer; Finally, stack another single-sided composite blank with the stainless steel surface facing down, so that the stainless steel surfaces of the two single-sided composite blanks are strictly aligned, the inner side of the L-shaped billet is closely attached to the cuboid protrusion of the single-sided composite blank, and the outer side of the L-shaped billet is flush with the outer side of the single-sided composite blank, forming a cuboid welded stack blank; (6) The stacked blanks to be welded are fed into the vacuum electron beam welding machine, and the joints between the L-shaped steel blank and the upper and lower single-sided composite blanks are welded respectively. Specifically, the gas pressure is controlled to be ≤1.0*10 in the vacuum electron beam welding machine. -2 Pa is used for sealing welding to obtain a composite blank; (7)Heat the composite blank and then send it into a rolling mill for rolling and cooling to obtain a composite steel plate; (8)Cut the four sides of the composite steel plate, cut off the part containing common carbon steel, and the steel plates are naturally separated to obtain two metal composite plate products of the same specification.

2. The symmetrical preform preparation method as described in claim 1, characterized in that, In step (3), first polish the surface and the bonding plane of the stainless steel plate respectively to remove all mill scale on the stainless steel plate and the bonding plane, and then stack and vacuum seal - weld them.

3. The symmetrical preform preparation method as described in claim 1, characterized in that, In step (3), after the stainless steel plate is strictly aligned with the edge of the mating plane, the gap width at the joint between the stainless steel plate and the mating plane is ≤0.4mm.

4. The symmetrical preform preparation method as described in claim 1, characterized in that, Step (3) After vacuum sealing, the penetration depth of the single-sided composite blank welded joint is tested to ensure that the penetration depth is ≥10mm; if the penetration depth is <10mm, the single-sided composite blank is sent back into the vacuum electron beam welder for vacuum sealing until the penetration depth is ≥10mm.

5. The symmetrical preform preparation method as described in claim 1, characterized in that, The thickness of the isolation layer in step (5) is 0.5~1.0mm.

6. The symmetrical preform preparation method as described in claim 1, characterized in that, Step (6) After welding, the weld depth of the composite billet is tested to ensure that the weld depth is ≥30mm; if the weld depth is <30mm, the single-sided composite billet is sent back into the vacuum electron beam welding machine for vacuum sealing until the weld depth is ≥30mm.

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