Titanium composite plate welding process and structure

Abstract

The present invention relates to the field of titanium composite plate welding technology, specifically to a titanium composite plate welding process method and structure, including carbon steel welded together and a titanium plate welded on the carbon steel, a first titanium connecting plate is welded between adjacent titanium plates, the first titanium connecting plate is bent downward to form a convex arch in the middle, the two ends of the first titanium connecting plate are welded to the corresponding titanium plates, the first titanium connecting plate and the end of the titanium plate are smoothly transitioned, the middle position of the first titanium connecting plate is located directly above the center of the carbon steel weld, a second titanium connecting plate that is similarly bent is provided above the first titanium connecting plate, the two ends of the second titanium connecting plate are welded to the titanium plates on the corresponding side, and the second titanium connecting plate and the titanium plate are smoothly transitioned. The present application can ensure that the weld is not stretched, ensure the quality of the weld, and ensure that there will be no weld cracks.

Description

Technical Field

[0001] The invention belongs to the technical field of titanium composite plate welding, in particular to a titanium composite plate welding process method and structure. Background Art

[0002] The specific gravity of titanium is about half of that of stainless steel and carbon steel. It has good acid and corrosion resistance, especially in low-oxidizing and chloride-containing media. These advantages determine that titanium is widely used in various fine chemicals, metallurgy, petroleum, seawater desalination, etc. However, the price of titanium is much higher than that of stainless steel and carbon steel, and it is not very economical. Therefore, the titanium composite plate that came into being has a very broad market space. It has both the corrosion resistance of titanium and the high strength of carbon steel. Under the premise of ensuring the quality of the equipment, it reduces the production cost of the equipment and obtains good economic benefits.

[0003] During the long-term use of composite plates, the most common defects are composite plate welding defects, which mainly exist in the cylinder, tube sheet and head. Because the linear expansion coefficients of titanium and carbon steel are different, after heating and pressure increase, the expansion and contraction per unit length of titanium and carbon steel are different, which can easily cause cracks in the welds. In severe cases, the welds may break, affecting the normal use of the equipment.

[0004] At present, the common welding form is to add a flat titanium connecting plate between the titanium plates to be welded to ensure that there is a certain distance between the weld of the carbon steel and the weld of the titanium plate to ensure the welding quality. Under low temperature and low pressure conditions, this type of welding is not easy to produce weld cracks due to temperature changes. However, when the equipment is under high temperature and high pressure working conditions, the linear expansion coefficients of titanium and carbon steel are quite different. Within a unit length, the linear expansion of titanium is less than that of carbon steel, and as the temperature rises, the difference between the two increases, and the titanium clad layer and the titanium weld are subjected to tensile thermal stress. If the welding quality of the titanium weld is poor, the weld may crack. Summary of the invention

[0005] The invention provides a titanium composite plate welding structure to solve the defects in the prior art.

[0006] The present invention is achieved through the following technical solutions:

[0007] A titanium composite plate welding structure comprises carbon steel welded together and two titanium plates welded on the carbon steel, a first titanium connecting plate is welded between adjacent titanium plates, the first titanium connecting plate is bent downward into an arch with a convex middle, both ends of the first titanium connecting plate are welded to corresponding titanium plates, the first titanium connecting plate is narrow at the top and wide at the bottom at the welding point and has a smooth transition to the end of the titanium plate, the middle position of the first titanium connecting plate is located directly above the center of the carbon steel weld, a second titanium connecting plate that is similarly bent is provided above the first titanium connecting plate, both ends of the second titanium connecting plate are welded to the titanium plates on the corresponding sides, the weld at the second titanium connecting plate is narrow at the top and wide at the bottom and has a smooth transition to the upper surface of the titanium plate.

[0008] When the device is in use, since the first titanium connecting plate is arched and therefore longer than the horizontal titanium connecting plate, when the temperature rises, the linear expansion coefficient of carbon steel is greater than that of titanium, and the expansion and contraction of carbon steel is greater than that of titanium. The extra expansion and contraction of the two is compensated by the first titanium connecting plate, and the first titanium connecting plate will be stretched, ensuring that the weld is not stretched. At the same time, the first titanium connecting plate and the corresponding titanium plate weld have a smooth transition, ensuring the quality of the weld and ensuring that there will be no weld cracks. Among them, the second titanium connecting plate can not only further eliminate the expansion and contraction of carbon steel and titanium plates, but also play a dual anti-corrosion role. Even if there is a problem with the first titanium connecting plate, it can also play a better anti-corrosion role.

[0009] Preferably, the center of the second titanium connecting plate is located directly above the center of the first titanium connecting plate, which can ensure that the stretching lengths of both ends of the second titanium connecting plate are consistent, thereby ensuring that the two welded carbon steels are subjected to the same force when stretched.

[0010] Preferably, the central angle of the second titanium connecting plate is greater than the central angle of the first titanium connecting plate, which can ensure that when the two welded carbon steels are stretched, the first titanium connecting plate first offsets the tensile force of the carbon steel. When the first titanium connecting plate cannot completely offset the tensile force of the carbon steel, the second titanium connecting plate further offsets the tensile force of the carbon steel, thereby ensuring that the number of times the second titanium connecting plate is used is less than the number of times the first titanium connecting plate is used, thereby better playing an anti-corrosion role.

[0011] Preferably, the length of the second titanium connecting plate is 2-3 times the length of the first titanium connecting plate, which can further ensure that the second titanium connecting plate starts to offset the tensile stress of the first titanium connecting plate before the tensile stress limit of the first titanium connecting plate, thereby ensuring the long-term use of the first titanium connecting plate.

[0012] Preferably, the distance from the center of the first titanium connecting plate to the carbon steel directly below, and the distance from the center of the second titanium connecting plate to the titanium plate directly below are both 2mm-3mm. The distance from the first titanium connecting plate to the carbon steel is 2mm-3mm, which can not only reduce the space occupied by the first titanium connecting plate above the carbon steel, but also reduce the first titanium connecting plate following the stretching of the carbon steel when the carbon steel is stretched. The distance from the center of the second titanium connecting plate to the titanium plate directly below is 2mm-3mm, which can effectively prevent the second titanium connecting plate from pushing the first titanium connecting plate downward when being stretched downward, and further prevent the first titanium connecting plate from being horizontally stretched.

[0013] Preferably, when the carbon steel weld angle is 60° and the thickness is 12 mm, when the lateral length of the first titanium connecting plate is 20 mm, the lateral length of the second titanium connecting plate is 50 mm, the thickness of the titanium plate, the first titanium connecting plate and the second titanium connecting plate are all 3 mm, the distance from the center of the first titanium connecting plate 3 to the carbon steel 1 is 2 mm, and the distance from the center of the second titanium connecting plate 4 to the titanium plate is 2 mm.

[0014] The beneficial effects of the present invention are as follows: when the device is in use, since the first titanium connecting plate is arched and therefore its length is greater than that of the horizontal titanium connecting plate, when the temperature rises, the linear expansion coefficient of the carbon steel is greater than that of the titanium material, and the expansion and contraction of the carbon steel is greater than that of the titanium material, and the excess expansion and contraction of the two is compensated by the first titanium connecting plate. Since the center of the first titanium connecting plate is located directly above the center of the carbon steel weld, the compensation amounts at both ends of the first titanium connecting plate are the same, and the first titanium connecting plate will be stretched to a horizontal state, ensuring that the weld is not stretched, and at the same time, the first titanium connecting plate and The corresponding titanium plate weld has a smooth transition, which ensures the quality of the weld and ensures that there will be no weld cracks; the second titanium connecting plate welded above the first titanium connecting plate can play a dual anti-corrosion performance on the basis of eliminating the difference in the expansion and contraction amount between the carbon steel and the titanium plate, and can better play an anti-corrosion performance even if there is a problem with the first titanium connecting plate. At the same time, the center of the second titanium connecting plate is located directly above the center of the first titanium connecting plate, which can ensure that the stretching lengths at both ends of the second titanium connecting plate are consistent, thereby ensuring that the two welded carbon steels are subjected to the same force when stretched. The center angle of the second titanium connecting plate is greater than the center angle of the first titanium connecting plate, which can ensure that when the two welded carbon steels are stretched, the first titanium connecting plate first offsets the tensile force of the carbon steel. When the first titanium connecting plate cannot completely offset the tensile force of the carbon steel, the second titanium connecting plate further offsets the tensile force of the carbon steel, thereby ensuring that the number of uses of the second titanium connecting plate is less than the number of uses of the first titanium connecting plate, thereby better playing an anti-corrosion role. The length of the second titanium connecting plate is 2-3 times that of the first titanium connecting plate, which can further ensure that the second titanium connecting plate starts to offset the tensile stress of the first titanium connecting plate before the tensile stress limit of the first titanium connecting plate, thereby ensuring the long-term use of the first titanium connecting plate.

[0015] The titanium composite plate welding process comprises the following steps:

[0016] (1) First, two pieces of carbon steel are welded together using a welding machine;

[0017] (2) Welding the titanium plates: placing the two titanium plates on the steel plates respectively and making the distance between the opposite ends of the titanium plates equal to the length of a first titanium connecting plate; then adjusting the distance between the opposite ends of the two titanium plates and the weld of the steel plates to be consistent and then welding the titanium plates to the carbon steel plates;

[0018] (3) Welding the first titanium connecting plate, placing the arched first titanium connecting plate with the arch center facing downward on the carbon steel plate between the two adjacent titanium plates and making the center of the first titanium connecting plate directly above the center of the weld of the carbon steel plate, then welding the two ends of the first titanium connecting plate to the corresponding ends of the titanium plates, and making the weld between the upper end surface of the first titanium connecting plate and the upper surface of the titanium plates smoothly transition;

[0019] (4) Welding the second titanium connecting plate. Place the arched second titanium connecting plate with the arch facing downward directly above the first titanium connecting plate so that the center of the first titanium connecting plate and the center of the second titanium connecting plate are on the same vertical line. Then, weld the two ends of the second titanium connecting plate to the upper surface of the corresponding titanium plate so that the upper surface of the second titanium connecting plate smoothly transitions to the upper surface of the titanium plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0021] Figure 1 It is a schematic diagram of the existing welding of titanium and carbon steel;

[0022] Figure 2 It is a schematic diagram of welding titanium material and carbon steel in this application.

[0023] As shown in the figure:

[0024] 1. Carbon steel, 2. Titanium plate, 3. First titanium connecting plate, 4. Second titanium connecting plate. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Titanium composite plate welding process and structure, such as Figure 2As shown. It includes a carbon steel plate 1 welded together with a narrow upper weld and a wide lower weld, and two titanium plates 2 welded to the carbon steel plate 1. The two ends of the first titanium connecting plate 3 are bent downward to form a convex arch in the middle. The bending center of the first titanium connecting plate 3 is located directly above the center of the weld of the two carbon steels 1. The two ends of the first titanium connecting plate 3 are welded to the corresponding titanium plates 2. The weld of the first titanium connecting plate 3 and the corresponding titanium plates 2 is wide at the top and narrow at the bottom, and the weld is smoothly transitioned. A second titanium connecting plate 4 is arranged above the first titanium connecting plate 3. The second titanium connecting plate 4 is arranged above the first titanium connecting plate 3. The center of the connecting plate 4 is located directly above the center of the first titanium connecting plate 3, and the two ends of the second titanium connecting plate 4 are welded to the upper surface of the titanium plate 2 on the corresponding side. The welding point between the second titanium connecting plate 4 and the upper surface of the titanium plate 2 has a smooth transition. The thickness of the first titanium connecting plate 3 is consistent with the thickness of the second titanium connecting plate 4. The thickness of the carbon steel 1 is 3-5 times the thickness of the first titanium connecting plate. The central angle of the second titanium connecting plate 4 is greater than the central angle of the first titanium connecting plate 3 and the length of the second titanium connecting plate 4 is 2-3 times the length of the first titanium connecting plate 3.

[0027] During welding, the present application welds two pieces of carbon steel 1 together using a welding machine, and then places two titanium plates 2 on the carbon steel 1 respectively so that the distance between the opposite ends of the titanium plates 2 is the length of a first titanium connecting plate 3. Then, the distance between the opposite ends of the two titanium plates 2 and the weld of the steel plates is adjusted to be consistent, and then the titanium plates 2 are welded to the carbon steel 1. Then, the arched first titanium connecting plate 3 is placed with the arch center downward on the carbon steel 1 plate between the two adjacent titanium plates 2 so that the center of the first titanium connecting plate 3 is located directly above the center of the weld of the carbon steel 1 plate. Then, the two ends of the first titanium connecting plate 3 are welded to the corresponding ends of the titanium plates 2, and the titanium connecting plate 3 is welded to the corresponding ends of the titanium plates 2. The weld between the plate and the titanium plate 2 is a smooth transition. Finally, the arched second titanium connecting plate 4 is placed downward directly above the first titanium connecting plate 3 and the center of the first titanium connecting plate 3 and the center of the second titanium connecting plate 4 are located on the same vertical line. Then the two ends of the second titanium connecting plate 4 are welded together with the corresponding titanium plate 2 and the weld and the upper surface of the titanium plate are smoothly transitioned. The centers of the first titanium connecting plate 3 and the second titanium connecting plate 4 are both located directly above the welds of the two carbon steels 1. The distance from the center of the first titanium connecting plate 3 to the carbon steel 1 and the distance from the center of the second titanium connecting plate 4 to the first titanium connecting plate directly below are both 1mm-2mm.

[0028] Among them, this welding form is also applicable to other special metal materials.

[0029] The advantage of this process is that since the first titanium connecting plate 3 is arched, its length is greater than that of the horizontal titanium connecting plate. Therefore, when the temperature rises, the linear expansion coefficient of the carbon steel 1 is greater than that of the titanium material, and the expansion and contraction of the carbon steel 1 is greater than that of the titanium material. The excess expansion and contraction of the two is compensated by the first titanium connecting plate 3. Since the center of the first titanium connecting plate 3 is located directly above the center of the weld of the carbon steel 1, the compensation amounts at both ends of the first titanium connecting plate 3 are the same, and the first titanium connecting plate 3 will be stretched to a horizontal state, ensuring that the weld is not stretched. At the same time, the weld of the first titanium connecting plate 3 and the corresponding titanium plate 2 has a smooth transition, which ensures the quality of the weld and ensures that there will be no weld cracks. The second The titanium connecting plate 4 can play a dual anti-corrosion role on the basis of eliminating the difference in expansion and contraction between the carbon steel 1 and the titanium plate 2. Even if there is a problem with the first titanium connecting plate 3, it can still play a better anti-corrosion role. At the same time, the central angle of the second titanium connecting plate 4 is greater than the central angle of the first titanium connecting plate 3, which can ensure that when the two welded carbon steels 1 are stretched, the first titanium connecting plate 3 first offsets the stretching force of the carbon steel 1. When the first titanium connecting plate 3 cannot completely offset the stretching force of the carbon steel 1, the second titanium connecting plate 4 further offsets the stretching force of the carbon steel 1, thereby ensuring that the number of times the second titanium connecting plate 4 is used is less than the number of times the first titanium connecting plate 3 is used, thereby ensuring that the second titanium connecting plate 4 can play a better anti-corrosion role. The length of the second titanium connecting plate 4 is greater than that of the first titanium connecting plate 3, which can ensure that when the first titanium connecting plate 2 is stretched, it can further ensure that before the first titanium connecting plate 3 reaches the tensile stress limit, the second titanium connecting plate 4 begins to offset the tensile stress of the first titanium connecting plate 3, thereby ensuring the long-term use of the first titanium connecting plate 3, and the center of the second titanium connecting plate 4 is located directly above the center of the first titanium connecting plate 3. It can ensure that the stretching lengths of both ends of the second titanium connecting plate 4 are consistent, thereby ensuring that the second titanium connecting plate 4 can be stretched horizontally. After the equipment stops working, the temperature will drop, and the carbon steel 1 and the titanium plate 2 will return to their original state. The expansion and contraction between the two will also be compensated by the titanium connecting plate, and the first titanium connecting plate 3 and the second titanium connecting plate 4 will return from horizontal to bent state, and this cycle can effectively ensure the quality of the weld. The distance from the first titanium connecting plate 3 to the carbon steel 1 is 2mm-3mm, which can not only reduce the space occupied by the first titanium connecting plate 3 above the carbon steel 1, but also reduce the stretching of the first titanium connecting plate 3 following the carbon steel 1 when the carbon steel 1 is stretched. The distance from the center of the second titanium connecting plate 4 to the first titanium connecting plate 3 directly below is 2mm-3mm, which can effectively prevent the second titanium connecting plate 4 from pushing the first titanium connecting plate 3 to move downward when being stretched, and further prevent the first titanium connecting plate 3 from being horizontally stretched.

[0030] Example 1

[0031] In the present application, when the weld angle of the carbon steel 1 is 60° and the thickness is 12 mm, the lateral length of the first titanium connecting plate 3 is 20 mm, the lateral length of the second titanium connecting plate 4 is 50 mm, the thickness of the titanium plate 2, the first titanium connecting plate 3 and the second titanium connecting plate 4 are all 3 mm, the distance from the center of the first titanium connecting plate 3 to the carbon steel 1 is 2 mm, and the distance from the center of the second titanium connecting plate 4 to the titanium plate is 2 mm.

[0032] In this embodiment, the length, thickness and gap corresponding to the first titanium connecting plate 3 and the second titanium connecting plate 4 can effectively offset the tensile stress of the carbon steel 1 in the embodiment, prevent gaps from appearing at the weld of the carbon steel 1, and ensure the long-term use of the welding plates.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A titanium composite plate welding structure, comprising carbon steel welded together and a titanium plate welded on the carbon steel, wherein a first titanium connecting plate is welded between adjacent titanium plates, characterized in that: The first titanium connecting plate is bent downward to form an arch with a convex middle. The two ends of the first titanium connecting plate are welded to the corresponding ends of the titanium plate. The first titanium connecting plate and the ends of the titanium plate are smoothly transitioned. The middle position of the first titanium connecting plate is located directly above the center of the carbon steel weld. A second titanium connecting plate that is also bent is provided above the first titanium connecting plate. The two ends of the second titanium connecting plate are welded to the titanium plates on the corresponding sides. The second titanium connecting plate and the upper surface of the titanium plate are smoothly transitioned. The bending center of the second titanium connecting plate is located directly above the bending center of the first titanium connecting plate.

2. The titanium composite plate welding structure according to claim 1, characterized in that: The central angle of the second titanium connecting plate is greater than the central angle of the first titanium connecting plate.

3. The titanium composite plate welding structure according to claim 1, characterized in that: The length of the second titanium material connecting plate is 2-3 times the length of the first titanium material connecting plate.

4. The titanium composite plate welding structure according to claim 3, characterized in that: The distance from the center of the first titanium connecting plate to the carbon steel directly below, and the distance from the center of the second titanium connecting plate to the first titanium connecting plate directly below are both 2mm-3mm.

5. The titanium composite plate welding structure according to claim 1, characterized in that: When the carbon steel weld angle is 60° and the thickness is 12mm, when the lateral length of the first titanium connecting plate is 20mm, the lateral length of the second titanium connecting plate is 50mm, the thickness of the titanium plate, the first titanium connecting plate and the second titanium connecting plate are all 3mm, the distance from the center of the first titanium connecting plate to the carbon steel is 2mm, and the distance from the center of the second titanium connecting plate to the titanium plate is 2mm.

6. The welding process method of the titanium composite plate welding structure according to any one of claims 1 to 5, characterized in that: The following steps are involved: (1) First, two pieces of carbon steel are welded together using a welding machine; (2) Welding the titanium plates: placing the two titanium plates on the steel plates respectively and making the distance between the opposite ends of the titanium plates equal to the length of a first titanium connecting plate; then adjusting the distance between the opposite ends of the two titanium plates and the weld of the steel plates to be consistent and then welding the titanium plates to the carbon steel plates; (3) Welding the first titanium connecting plate, placing the arched first titanium connecting plate with the arch center facing downward on the carbon steel plate between the two adjacent titanium plates and making the center of the first titanium connecting plate directly above the center of the weld of the carbon steel plate, then welding the two ends of the first titanium connecting plate to the corresponding ends of the titanium plates, and making the weld between the upper end surface of the first titanium connecting plate and the upper surface of the titanium plates smoothly transition; (4) Welding the second titanium connecting plate. Place the arched second titanium connecting plate with the arch facing downward directly above the first titanium connecting plate so that the center of the first titanium connecting plate and the center of the second titanium connecting plate are on the same vertical line. Then, weld the two ends of the second titanium connecting plate to the upper surface of the corresponding titanium plate so that the upper surface of the second titanium connecting plate smoothly transitions to the upper surface of the titanium plate.

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