A billet assembly process for a high compression ratio double-sided titanium composite coil

Abstract

This invention relates to the field of composite coil manufacturing technology, specifically to a billet assembly process for high-compression-ratio double-sided titanium composite coils. The process includes: Step 1, preparing the substrate; Step 2, surface treatment; Step 3, billet assembly; Step 4, vacuum electron beam welding; Step 5, hot rolling; and Step 6, cold rolling. This invention's billet assembly process for high-compression-ratio double-sided titanium composite coils enables large-scale mass production (up to 25 tons per single billet rolled). The process is simple, requiring only a combination of 3 layers of sheet metal and 2 transition layers, reducing rolling risks and difficulties. Compared to traditional cladding-type stacking rolling processes, it eliminates steps such as beveling, drilling vacuum holes, vacuuming, and applying release agents, improving work efficiency and reducing labor costs. Furthermore, only five layers of raw materials are required, reducing rolling difficulty; the yield rate can reach 98% ± 1%, saving significant raw material costs and achieving cost reduction and efficiency improvement.

Description

Technical Field

[0001] This invention relates to the field of composite coil preparation technology, and more specifically, to a blanking process for a high compression ratio double-sided titanium composite coil. Background Technology

[0002] Currently, the rolling technology for titanium composite plates is mainly based on cladding rolling, but the current cladding rolling technology still has some shortcomings.

[0003] For example, patent publication number CN109693430B discloses a method for preparing thin-layered double-sided titanium composite plates using a cladding-rolling process. This method requires seven layers: a cover plate, a release agent, a titanium cladding layer, a base layer, another titanium cladding layer, a release agent, and a cover plate. In this method, the cover plate becomes scrap after rolling, resulting in a yield of only 85% and significant waste of raw materials. Secondly, patent publication number CN102773670B discloses a method for preparing titanium-steel-titanium double-sided composite plates. This method also uses a rolling process, requiring 13 layers: three steel plates, four titanium plates, four transition layers, and two release agent layers. It involves beveling, drilling vacuum holes, applying release agent, and sealing, making the preparation process cumbersome, requiring a large amount of manual labor, and the yield is only around 80%, again wasting a significant amount of raw materials. Furthermore, the production capacity of cladding-rolling is low, with a single rolling slab weighing only 5-10 tons.

[0004] Therefore, there is an urgent need for a high compression ratio double-sided titanium composite coil assembly process to overcome the shortcomings of existing technologies. Summary of the Invention

[0005] The purpose of this invention is to provide a blanking process for high compression ratio double-sided titanium composite coils to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides a preforming process for high compression ratio double-sided titanium composite coils, comprising the following steps:

[0007] Step 1: Material Preparation: Prepare the base material, composite material, and edge welding plates. The composite material is a titanium plate, preferably a single-sided titanium plate. The thickness of the titanium plate is 10% of the thickness of the base material. The width of the titanium plate is equal to the width of the base material plus 40-60mm, and the length is equal to the length of the base material plus 40-60mm. By splicing these dimensions, a standard cuboid can be formed. Due to the chemical properties of titanium, it cannot be welded to the internal carbon steel. Only the welding plates can form a sealed cavity to achieve subsequent vacuum rolling. If the dimensions are not followed, it may lead to insufficient welding strength, damage to the sealed cavity during processing, and scrapping of the slab. Prepare two long and two short edge welding plates. The length of the long edge welding plate is equal to the length of the titanium plate, the width is equal to the thickness of the base material, and the thickness is equal to (titanium plate width - base material width) / 2. The length of the short edge welding plate is equal to the width of the titanium plate, the width is equal to the thickness of the base material, and the thickness is equal to (titanium plate length - base material length) / 2.

[0008] Step 2, Surface treatment: All six sides of the substrate are surface treated to remove the surface oxide layer and impurities. Only the contact surfaces of the titanium plate and edge welding plate are treated (the contact surfaces are machined by milling or grinding to achieve a surface roughness Ra≤35). The outer surfaces are not treated.

[0009] Step 3, Assembly: Apply a Ti-based brazing layer with a thickness of less than 1mm to all six sides of the substrate. Then, place the raw materials in the order of titanium plate, substrate, and titanium plate. Next, place the four edge welding plates in the designated positions to make the slab into a cuboid. In the prior art, a sealed cavity is usually manufactured outside the titanium plate. The method of assembling the slab in this invention is to directly use the titanium plate as the sealed cavity. This improves the material utilization rate, and the surface quality of the finished product is higher than that produced by the usual method. In addition, the production capacity is also greatly improved.

[0010] Step 4, Vacuum Electron Beam Welding: The assembled slab is sent into the vacuum chamber, and after the vacuum is removed, edge welding is performed (using a vacuum electron beam machine for welding, the penetration depth must be no less than the thickness of the welding plate) to form a composite slab. The vacuum value is controlled within the range of 1×10-2 Pa to 1×10-3 Pa. The lower the vacuum value, the higher the vacuum degree and the higher the welding quality, but considering the cost, this range is sufficient.

[0011] Step 5, Hot Rolling: The welded composite slab is fed into a heating furnace for heating, which is divided into a preheating section and a soaking section. The preheating section temperature is 400-700℃, and the preheating time is 60-120 minutes. The soaking section temperature is 850-950℃, and the heating time is 80-150 minutes. The total heating time should not exceed 1.2 minutes / mm × base material thickness + 1.5 minutes / mm × composite material thickness. Subsequently, six passes of rough rolling are performed. The initial rolling temperature is controlled at 850-900℃, and the minimum single-pass reduction rate of the first five rough rolling passes is controlled to be no less than 20%. The sixth rough rolling pass is adjusted according to the situation to ensure that the composite slab meets the requirements for entering the finishing mill. The finishing mill adopts a seven-stand continuous rolling mill, and the overall reduction rate is controlled at 50-90%. The initial rolling temperature of the finishing mill is no less than 780℃. After rolling, the slab is annealed and pickled to obtain hot-rolled double-sided titanium composite coil.

[0012] Step 6, Cold Rolling: The hot-rolled double-sided titanium composite coil is cold-rolled according to the conventional cold rolling process requirements for titanium materials to finally obtain a high compression ratio double-sided titanium composite coil.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0014] 1. The billet assembly process of this high compression ratio double-sided titanium composite coil enables large-scale mass production of double-sided titanium composite coils (the production weight of a single billet rolled in one operation can reach 25 tons). The process is simple, requiring only a combination of 3 layers of sheet and 2 layers of transition layer, which reduces the rolling risk and difficulty. Compared with the traditional cladding rolling process, it eliminates steps such as beveling, drilling vacuum holes, vacuuming, and applying release agent, thereby improving work efficiency and reducing labor costs.

[0015] 2. In the billet assembly process of this high compression ratio double-sided titanium composite coil, only five layers of raw materials are required, which reduces the rolling difficulty; the yield rate can reach 98%±1%, saving a lot of raw material costs and achieving the effect of cost reduction and efficiency improvement. At the same time, the average shear strength of this product can reach more than 250Mpa, the tensile strength can reach 470-490MPa, the yield strength can reach 360-378MPa, and the plate bonding rate can reach 100%, meeting the national Class 1 titanium composite plate standard (GB / T8547-2019). Attached Figure Description

[0016] Figure 1 This is an overall flowchart of Embodiment 1 of the present invention;

[0017] Figure 2 This is a schematic diagram of the assembly structure according to an embodiment of the present invention.

[0018] Meaning of each label in the diagram:

[0019] 10. Substrate; 20. Composite material; 30. Edge welding plate; 40. Ti-based brazing layer. Detailed Implementation

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0021] according to Figure 1 As shown, this embodiment of the invention provides a preforming process for a high compression ratio double-sided titanium composite coil, including the following steps:

[0022] Step 1: Prepare materials: Prepare base material 10, composite material 20, and edge welding plate 30. Composite material 20 is a titanium plate, specifically a single-sided titanium plate. The thickness of the titanium plate is 10% of the thickness of base material 10. The width of the titanium plate is equal to the width of base material 10 plus 40mm, and the length is equal to the length of base material 10 plus 40mm. Prepare two long and two short edge welding plates 30. The length of the long edge welding plate 30 is equal to the length of the titanium plate, the width is equal to the thickness of base material 10, and the thickness is equal to (titanium plate width - base material 10 width) / 2. The length of the short edge welding plate 30 is equal to the width of the titanium plate, the width is equal to the thickness of base material 10, and the thickness is equal to (titanium plate length - base material 10 length) / 2.

[0023] Step 2, Surface treatment: All six sides of the substrate 10 are surface treated to remove the surface oxide layer and impurities. The titanium plate and the edge welding plate 30 are only treated on the contact surface (the contact surface is machined by milling or grinding to achieve a surface roughness Ra≤35). The outer surface is not treated.

[0024] Step 3, Assembly: Apply a Ti-based brazing layer 40 with a thickness of less than 1mm to all six sides of the substrate 10. Adding the Ti-based brazing layer 40 can improve the bonding strength between the two plates, thereby improving the bonding rate, shear strength and other indicators of the finished product. Then, place the raw materials in the order of titanium plate, substrate 10, and titanium plate. Then, place the four edge welding plates 30 in the designated positions to make the slab into a cuboid.

[0025] Step 4, Vacuum Electron Beam Welding: The assembled slab is sent into the vacuum chamber, and after the vacuum is removed, edge welding is performed (using a vacuum electron beam machine for welding, the penetration depth must be not less than the thickness of the welding plate) to form a composite slab, and the vacuum value is controlled within the range of 1×10-2 Pa to 1×10-3 Pa.

[0026] Step 5, Hot Rolling: The welded composite slab is fed into a heating furnace for heating. The heating process is divided into a preheating section and a soaking section. The preheating temperature is 400℃ and the preheating time is 60 minutes. The soaking temperature is 900℃ and the heating time is 120 minutes. The total heating time does not exceed 1.2 minutes / mm × base material thickness 10 + 1.5 minutes / mm × composite material thickness 20. Subsequently, six passes of rough rolling are performed. The initial rolling temperature is controlled at 850℃. The minimum single-pass reduction rate of the first five rough rolling passes is controlled to be no less than 20%. The sixth rough rolling pass is adjusted according to the situation to ensure that the composite slab meets the requirements for entering the finishing mill. The finishing mill adopts a seven-stand continuous rolling mill, controlling the overall reduction rate at 70%. The initial rolling temperature of the finishing mill is 780℃. After rolling, the slab is annealed and pickled to obtain the hot-rolled double-sided titanium composite coil.

[0027] Step 6, Cold Rolling: The hot-rolled double-sided titanium composite coil is cold-rolled according to the conventional cold rolling process of titanium materials (the cold rolling process in this embodiment adopts the conventional cold rolling process of steel plate, which is the existing technology and will not be described in detail in this embodiment) to achieve the cold rolling of the double-sided titanium composite coil, and finally obtain a high compression ratio double-sided titanium composite coil. Example

[0028] This invention provides a preforming process for high compression ratio double-sided titanium composite coils, comprising the following steps:

[0029] Step 1: Prepare materials: Prepare base material 10, composite material 20, and edge welding plate 30. Composite material 20 is a titanium plate, specifically a single-sided titanium plate. The thickness of the titanium plate is 10% of the thickness of base material 10. The width of the titanium plate is equal to the width of base material 10 plus 50mm, and the length is equal to the length of base material 10 plus 50mm. Prepare two long and two short edge welding plates 30. The length of the long edge welding plate 30 is equal to the length of the titanium plate, the width is equal to the thickness of base material 10, and the thickness is equal to (titanium plate width - base material 10 width) / 2. The length of the short edge welding plate 30 is equal to the width of the titanium plate, the width is equal to the thickness of base material 10, and the thickness is equal to (titanium plate length - base material 10 length) / 2.

[0030] Step 2, Surface treatment: All six sides of the substrate 10 are surface treated to remove the surface oxide layer and impurities. The titanium plate and the edge welding plate 30 are only treated on the contact surface (the contact surface is machined by milling or grinding to achieve a surface roughness Ra≤35). The outer surface is not treated.

[0031] Step 3, Assembly: Apply a Ti-based brazing layer 40 with a thickness of less than 1mm to all six sides of the substrate 10. Adding the Ti-based brazing layer 40 can improve the bonding strength between the two plates, thereby improving the bonding rate, shear strength and other indicators of the finished product. Then, place the raw materials in the order of titanium plate, substrate 10, and titanium plate. Then, place the four edge welding plates 30 in the designated positions to make the slab into a cuboid.

[0032] Step 4, Vacuum Electron Beam Welding: The assembled slab is sent into the vacuum chamber, and after the vacuum is removed, edge welding is performed (using a vacuum electron beam machine for welding, the penetration depth must be not less than the thickness of the welding plate) to form a composite slab, and the vacuum value is controlled within the range of 1×10-2 Pa to 1×10-3 Pa.

[0033] Step 5, Hot Rolling: The welded composite slab is fed into a heating furnace for heating. The heating process is divided into a preheating section and a soaking section. The preheating temperature is 500℃ and the preheating time is 90 minutes. The soaking temperature is 950℃ and the heating time is 150 minutes. The total heating time does not exceed 1.2 minutes / mm × base material thickness 10 + 1.5 minutes / mm × composite material thickness 20. Subsequently, six passes of rough rolling are performed. The initial rolling temperature is controlled at 880℃. The minimum single-pass reduction rate of the first five rough rolling passes is controlled to be no less than 20%. The sixth rough rolling pass is adjusted according to the situation to ensure that the composite slab meets the requirements for entering the finishing mill. The finishing mill adopts a seven-stand continuous rolling mill, controlling the overall reduction rate at 60%. The initial rolling temperature of the finishing mill is no less than 800℃. After rolling, the slab is annealed and pickled to obtain hot-rolled double-sided titanium composite coil.

[0034] Step 6, Cold Rolling: The hot-rolled double-sided titanium composite coil is cold-rolled according to the conventional cold rolling process of titanium materials (the cold rolling process in this embodiment adopts the conventional cold rolling process of steel plate, which is the existing technology and will not be described in detail in this embodiment) to achieve the cold rolling of the double-sided titanium composite coil, and finally obtain a high compression ratio double-sided titanium composite coil. Example

[0035] This invention provides a preforming process for high compression ratio double-sided titanium composite coils, comprising the following steps:

[0036] Step 1: Prepare materials: Prepare base material 10, composite material 20, and edge welding plate 30. Composite material 20 is a titanium plate, specifically a single-sided titanium plate. The thickness of the titanium plate is 10% of the thickness of base material 10. The width of the titanium plate is equal to the width of base material 10 plus 60mm, and the length is equal to the length of base material 10 plus 60mm. Prepare two long and two short edge welding plates 30. The length of the long edge welding plate 30 is equal to the length of the titanium plate, the width is equal to the thickness of base material 10, and the thickness is equal to (titanium plate width - base material 10 width) / 2. The length of the short edge welding plate 30 is equal to the width of the titanium plate, the width is equal to the thickness of base material 10, and the thickness is equal to (titanium plate length - base material 10 length) / 2.

[0037] Step 2, Surface treatment: All six sides of the substrate 10 are surface treated to remove the surface oxide layer and impurities. The titanium plate and the edge welding plate 30 are only treated on the contact surface (the contact surface is machined by milling or grinding to achieve a surface roughness Ra≤35). The outer surface is not treated.

[0038] Step 3, Assembly: Apply a Ti-based brazing layer 40 with a thickness of less than 1mm to all six sides of the substrate 10. Adding the Ti-based brazing layer 40 can improve the bonding strength between the two plates, thereby improving the bonding rate, shear strength and other indicators of the finished product. Then, place the raw materials in the order of titanium plate, substrate 10, and titanium plate. Then, place the four edge welding plates 30 in the designated positions to make the slab into a cuboid.

[0039] Step 4, Vacuum Electron Beam Welding: The assembled slab is sent into the vacuum chamber, and after the vacuum is removed, edge welding is performed (using a vacuum electron beam machine for welding, the penetration depth must be not less than the thickness of the welding plate) to form a composite slab, and the vacuum value is controlled within the range of 1×10-2 Pa to 1×10-3 Pa.

[0040] Step 5, Hot Rolling: The welded composite slab is fed into a heating furnace for heating. The heating process is divided into a preheating section and a soaking section. The preheating temperature is 600℃ and the preheating time is 75 minutes. The soaking temperature is 900℃ and the heating time is 120 minutes. The total heating time does not exceed 1.2 minutes / mm × base material thickness 10 + 1.5 minutes / mm × composite material thickness 20. Subsequently, six passes of rough rolling are performed. The initial rolling temperature is controlled at 870℃. The minimum single-pass reduction rate of the first five rough rolling passes is controlled to be no less than 20%. The sixth rough rolling pass is adjusted according to the situation to ensure that the composite slab meets the requirements for entering the finishing mill. The finishing mill adopts a seven-stand continuous rolling mill, controlling the overall reduction rate at 80%. The initial rolling temperature of the finishing mill is 790℃. After rolling, the slab is annealed and pickled to obtain hot-rolled double-sided titanium composite coil.

[0041] Step 6, Cold Rolling: The hot-rolled double-sided titanium composite coil is cold-rolled according to the conventional cold rolling process of titanium materials (the cold rolling process in this embodiment adopts the conventional cold rolling process of steel plate, which is the existing technology and will not be described in detail in this embodiment) to achieve the cold rolling of the double-sided titanium composite coil, and finally obtain a high compression ratio double-sided titanium composite coil.

[0042] Comparative Example 1

[0043] This comparative example adopts a method for preparing thin cladding double-sided titanium composite plates by cladding and rolling, which is prior art and will not be described in detail here.

[0044] Comparative Example 2

[0045] This comparative example uses a method for preparing a titanium-steel-titanium double-sided composite plate disclosed in patent publication number CN102773670B. This is prior art, and will not be described in detail here.

[0046] Table 1. Comparison of yield rates between the examples and the comparative examples

[0047] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Average yield (%) 97 99 98 85 80

[0048] As can be seen from Table 1, the average yield of the high compression ratio double-sided titanium composite coil assembly process provided in Examples 1-3 of this invention is higher than that of the methods provided in Comparative Examples 1 and 2, with a yield at least 10% higher. This indicates that the process of this invention is an important factor affecting the yield of double-sided titanium composite coils.

[0049] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A billet assembly process for high compression ratio double-sided titanium composite coils, characterized in that, Includes the following steps: Step 1: Prepare the substrate (10), composite material (20) and edge welding plate (30). The composite material (20) is a single-sided titanium plate. The thickness of the titanium plate is 10% of the thickness of the substrate (10). The width of the titanium plate is equal to the width of the substrate (10) plus 40-60mm, and the length is equal to the length of the substrate (10) plus 40-60mm. The edge welding plate (30) has two long and two short sides. The length of the long side welding plate (30) is equal to the length of the titanium plate, and the width is equal to the thickness of the substrate (10). The thickness is equal to (titanium plate width - substrate (10) width) / 2. The length of the short side welding plate (30) is equal to the width of the titanium plate, and the width is equal to the thickness of the substrate (10). The thickness is equal to (titanium plate length - substrate (10) length) / 2. Step 2: Surface treatment is performed on all six sides of the substrate (10) to remove the surface oxide layer and impurities. Only the contact surfaces of the titanium plate and the edge welding plate (30) are treated, and the outer surfaces are not treated. Step 3: Apply TI-based brazing layer (40) to all six sides of the substrate (10), then place the raw materials in the order of titanium plate, substrate (10), and titanium plate, and then place the four edge welding plates (30) in the designated position to make the slab into a cuboid. Step 4: The assembled slab is sent into the vacuum chamber, and after the vacuum is removed, the edges are welded to form a composite slab. Step 5: The welded composite slab is sent into a heating furnace for heating, which is divided into a preheating section and a soaking section; then, six passes of rough rolling are performed; the finish rolling is carried out using a seven-stand continuous rolling mill. After rolling, the hot-rolled double-sided titanium composite coil is obtained after annealing and pickling. Step 6: The hot-rolled double-sided titanium composite coil is cold-rolled according to the cold rolling process to finally obtain a high compression ratio double-sided titanium composite coil. In step four, the vacuum value ranges from 1×10⁻⁶. -2 Pa to 1×10 -3 Within the Pa interval; In step five, the preheating temperature is 400-700℃, the preheating time is 60-120min, the uniform heating temperature is 850-950℃, the heating time is 80-150min, and the total heating time does not exceed 1.2min / mm×substrate (10) thickness + 1.5min / mm×composite (20) thickness; In step five, the initial rolling temperature is controlled at 850-900℃, and the minimum single reduction rate of the first five rough rolling passes is not less than 20%. In step five, the overall reduction rate of finishing rolling is 50-90%, and the starting temperature of finishing rolling is not lower than 780℃.

2. The assembly process of the high compression ratio double-sided titanium composite coil according to claim 1, characterized in that: In step two, the contact surface is machined using either milling or grinding to achieve a surface roughness Ra≤35.

3. The assembly process of the high compression ratio double-sided titanium composite coil according to claim 1, characterized in that: In step three, the thickness of the TI-based solder layer (40) is less than 1 mm.

4. The assembly process of the high compression ratio double-sided titanium composite coil according to claim 1, characterized in that: In step four, a vacuum electron beam machine is used for edge welding, and the penetration depth is not less than the thickness of the welding plate.

Images