A forged and welded cable saddle welding method

Abstract

This invention discloses a forged and welded cable saddle welding method, comprising at least two forged steel parts used as forming the saddle groove bottom plate; including: 1. fixing the forged steel parts one and two to be joined on a shaping fixture, forming a butt joint between the forged steel parts one and two with a narrow bottom and wide opening, and no gap at the bottom; 2. preheating the forged steel parts one and two before welding; 3. performing heat preservation treatment on the preheated parts; 4. performing penetration welding at the butt joint to form an integral bent forged steel part on the shaping fixture; 5. stress relief and flaw detection treatment on the integral bent forged steel part; if there are other forged steel parts to be welded, repeat steps 1 to 5; after welding is completed, remove the shaping fixture and proceed to subsequent processing. This invention forms an arc-shaped arched saddle groove bottom plate by welding multiple forged steel parts. The formed saddle groove bottom plate has reliable quality and excellent mechanical properties. The forming method is simple and easy to implement, which helps to reduce machining work and material waste, resulting in significant economic benefits.

Description

Technical Field

[0001] This invention relates to a method for forming cable saddles for suspension bridges, specifically a welding method for a forged and welded cable saddle, or more precisely, a method for welding the saddle groove bottom plate of a forged and welded cable saddle using forged steel parts. Background Technology

[0002] In suspension bridge structures, cable saddles (including main cable saddles and auxiliary cable saddles) are key load-bearing components that support and steer the main cables. Traditionally, the saddle head is formed from a casting. However, due to the relatively loose internal structure of castings, castings often have casting defects such as shrinkage cavities, porosity, and air holes. As a result, the mechanical properties of cast cable saddles are poor, making them difficult to meet the load-bearing requirements of large suspension bridges.

[0003] In view of this, in recent years, applicants have attempted to use forged steel parts with dense internal structure and excellent mechanical properties as the forming structure of the cable saddle head, that is, using forged steel parts as the bottom plate of the cable saddle groove and steel plates as the wall plates of the cable saddle groove, thus forming a forged and welded cable saddle structure. For example, the Chinese patent documents published under the titles of "A forged and welded main cable saddle structure for suspension bridges" (Publication No. CN 214245370 U, Publication Date September 21, 2021), "A forged and welded pendulum-type cable saddle structure for suspension bridges" (Publication No. CN215801030 U, Publication Date February 11, 2022), and "A forged and welded seat-type cable saddle structure for suspension bridges" (Publication No. CN 215801031 U, Publication Date February 11, 2022), etc.

[0004] However, since forged steel parts are formed by repeated vertical forging using a hydraulic press hammer, resulting in a cylindrical or cuboid shape, while the saddle groove bottom plate of the cable saddle has an arched curved surface structure, there is currently no effective method for machining the cylindrical or cuboid forged steel parts into an arched structure. The current processing technology is the traditional cutting and shaping method, which involves gradually machining the cylindrical or cuboid forged steel parts, matching the width and length of the saddle groove bottom plate, into an arched structure. This inevitably increases the amount of machining work significantly, generates a large amount of forged steel scrap, drastically reduces the manufacturing efficiency of the cable saddle, and significantly increases manufacturing costs, resulting in poor economic benefits. Furthermore, this method relies on large-sized integral forged steel parts, which further increases the technical difficulty and cost of cable saddle manufacturing.

[0005] In summary, based on the above-mentioned design structure of the cable saddle formed from forged steel parts, and the special characteristics of forged steel parts themselves, it is necessary to independently develop an economical, practical, and reliable operating method based on the cable saddle formed from forged steel parts. Summary of the Invention

[0006] The technical objective of this invention is to provide a simple, reliable, and practical welding method for forged and welded cable saddles, taking into account the design structure of cable saddles formed from forged steel parts and the special characteristics of forged steel parts themselves. More precisely, it is a method for welding the saddle groove bottom plate of a forged and welded cable saddle with forged steel parts.

[0007] The technical objective of this invention is achieved through the following technical solution: a forged and welded cable saddle welding method, comprising at least two forged steel parts used as the bottom plate of the forming cable saddle groove; The welding method includes the following process steps: Step 1. Fix the forged steel parts 1 and 2 to be joined on a common shaping fixture, forming a joint between the forged steel parts 1 and 2 with a narrow bottom and wide opening and no gap at the bottom; Step 2. Perform preheating treatment on forged steel part one and forged steel part two before welding; Step 3. Transfer the preheated forged steel parts 1 and 2 to the welding station, and perform heat insulation treatment on the butt joint between forged steel parts 1 and 2. Step 4. Perform penetration welding at the joint until forged steel part one and forged steel part two are welded into an integral bent forged steel part on the shaping fixture; Step 5. Perform stress-relieving heat treatment and weld flaw detection on the integral bent forged steel part; If the flaw detection is qualified, and there are other forged steel parts to be welded, repeat steps 1 to 5 to form a new integral bent forged steel part on the shaping tooling. If the flaw detection is qualified, and all the forged steel parts constituting the bottom plate of the cable saddle groove are welded, the shaping tooling is removed, and the whole bent forged steel part is transferred to subsequent machining processing.

[0008] The above-mentioned technical measures address the design structure of the cable saddle formed from forged steel parts. Due to the unique characteristics of the forged steel part structure itself and the arched shape of the bottom plate of the cable saddle groove, the forged steel part forming the bottom plate of the saddle groove is formed by segmented butt joint assembly structure, without relying on a large-sized integral forged steel part. This approach helps to reduce the technical difficulty of manufacturing cable saddles from forged steel parts, ensures the forging quality of the forged steel parts, controls the manufacturing cost of the cable saddle, and makes the design of manufacturing cable saddles from forged steel parts more practical and feasible.

[0009] Based on the relatively independent segmentation of the forged steel parts of the formed saddle groove bottom plate, the above-mentioned technical measures use a fixed tooling to specifically clamp and position the two relative forged steel parts that need to be combined, so as to ensure that the overall linear contour of the combined forged steel parts can reliably meet the arched arc structure of the saddle groove bottom plate, while ensuring the precise forming of the butt joint between the forged steel parts, preventing relative deformation of the butt joint during the welding process, which is conducive to high-quality welding, and ensuring that the machining allowance of the bottom surface of the forged steel parts is not affected by welding. The above-mentioned technical measures, through preheating before welding, heat preservation during welding, and stress relief after welding of the forged steel parts to be welded on the fixed tooling, enable the high-quality forming of the weld between the relative forged steel parts, eliminate internal structural stress defects, and meet the internal quality requirements of the forged steel parts.

[0010] Therefore, the above-mentioned technical measures form the saddle groove bottom plate with an arc-shaped arch structure by welding multiple sections of forged steel. The formed saddle groove bottom plate has reliable quality and excellent mechanical properties. The forming method is simple and easy to implement, which helps to reduce the amount of machining work and material waste. Compared with the cutting and shaping method of large-size forged steel parts, the above-mentioned technical measures are more efficient, economical and practical, with significant economic benefits.

[0011] In step 1, the first forged steel part and the second forged steel part are fixed to the shaping fixture by segment welding. Each welding position of the segment weld adopts a double-sided fillet weld, the length of each segment weld is 250-350mm, and the spacing between two adjacent segments weld is 100-150mm.

[0012] The above-mentioned technical measures address the unique challenges of forged steel parts requiring clamping and positioning on a shaping fixture, the need for the fixture to work in conjunction with the forged steel parts for heat treatment and welding, and the requirement to remove the shaping fixture from the forged steel parts after welding. By fixing the forged steel parts to the shaping fixture using segmented welding, the bottom surface of the forged steel parts can form a tight fit with the top surface of the shaping fixture. This segmented welding method not only meets the technical requirements for stable clamping and positioning of the forged steel parts on the shaping fixture, but also facilitates the removal of the shaping fixture after welding. Furthermore, it ensures that the shaping fixture does not interfere with the heat treatment and welding operations of the forged steel parts, thus helping to ensure welding quality.

[0013] The shaping tooling mainly consists of multiple longitudinal ribs and multiple transverse ribs forming a frame structure in a longitudinal and transverse interwoven structure; Multiple longitudinal ribs are arranged at intervals in the width direction corresponding to the bottom plate of the saddle groove; Multiple transverse ribs are divided into multiple groups. The transverse ribs in each group are arranged at intervals along the length direction corresponding to the bottom plate of the saddle groove. Each transverse rib in each group is arranged sequentially between two adjacent longitudinal ribs along the width direction. The bottom of the shaping fixture is a flat bottom structure, and the top is an arched structure adapted to the arc-shaped contour of the saddle groove. The forged steel parts one and two are arranged according to the designed bending structure and fixed at the arch of the shaping fixture.

[0014] The aforementioned fixture is specifically designed for the saddle groove base plate assembled from forged steel parts. Its structure is simple and stable, and the main contour of the forged steel parts clamped and positioned by it is adapted to the main design contour of the saddle groove base plate, demonstrating strong specificity. Furthermore, the fixture structure facilitates balanced and reliable heat treatment and insulation of the forged steel parts.

[0015] In step 1, the butt joint formed between the first forged steel part and the second forged steel part is a U-shaped blunt-edge butt joint; the thickness of the blunt edge of the butt joint is 4-6 mm. This technical measure, while meeting the welding operation requirements, helps to reduce the amount of deposited metal and also helps to reduce welding deformation and welding workload.

[0016] Furthermore, at the bottom of the butt joint between the forged steel parts one and two, an anti-burn-through gasket is provided between the shaping fixture and the forged steel parts one and two. This technical measure can reliably prevent burn-through at the butt joint of the forged steel parts, thereby ensuring the quality of the weld.

[0017] The forged steel parts 1 and 2 at one end of the joint are connected to an outwardly extending arc-guiding unit that elongates the joint. The arc-guiding unit mainly consists of an arc-guiding side plate connected to the corresponding surfaces of the forged steel parts 1 and 2, and an arc-guiding bottom plate connected between the bottoms of the two arc-guiding side plates. It extends outward in a U-shape at the end of the joint. The forged steel parts 1 and 2 at the other end of the joint are connected to an outwardly extending arc-extinguishing unit that elongates the joint. The arc-extinguishing unit mainly consists of an arc-extinguishing side plate connected to the corresponding surfaces of the forged steel parts 1 and 2, and an arc-extinguishing bottom plate connected between the bottoms of the two arc-extinguishing side plates. The arc-extinguishing unit extends outward in a U-shape at the end of the joint.

[0018] The aforementioned forming structure of the arc-starting and arc-extinguishing units at both ends of the butt joint ensures the uniformity of the welding structure at the butt joint between forged steel parts, avoids the arc-starting and arc-extinguishing ends from adversely affecting the main welding quality, and thus ensures the welding quality between forged steel parts.

[0019] In step 2, the preheating treatment before welding involves sending the shaping fixture together with the fixed forged steel part one and forged steel part two into the heating furnace as a whole, heating the workpiece as a whole to 280~320℃ in the heating furnace at a heating rate of ≤70℃ / h, and then holding it at that temperature for 2~3h. After the flux is dried at 280-320℃ for 2-3 hours, it is placed in an insulated container for storage.

[0020] The aforementioned preheating treatment, applied to the full penetration welding operation between the forged steel parts, helps ensure high-quality weld formation and eliminates residual stress inside the weld.

[0021] In step 3, the heat preservation treatment of the preheated workpiece is achieved by inserting a heating tube onto the shaping fixture below the butt joint. The shaping fixture has at least two sets of heating tube insertion holes spaced below the butt joint.

[0022] The above-mentioned technical measures can provide even and reliable heat insulation for the joints of forged steel parts.

[0023] In step 4, the penetration welding process is performed using a narrow-gap submerged arc automatic welding machine; The welding current for the root pass is 470–490A, the welding voltage is 28–32V, and the welding speed is 480–520mm / min. The welding current for the remaining layers is 520–540A, the welding voltage is 30–34V, and the welding speed is 320–340mm / min. During the welding process, for each weld layer with a bevel width of less than 30mm, welding is performed by welding one pass on the left and one pass on the right; for each weld layer with a bevel width exceeding 30mm, welding is performed by welding one pass on the left, one pass in the middle, and one pass on the right. During the welding process, the flux initiates the arc at the arc-initiating unit outside the butt joint, and the flux extinguishes the arc at the arc-extinguishing unit outside the butt joint. During the welding process, after each weld layer is completed, the weld seam is cleaned to remove slag and flux residue.

[0024] The above-mentioned full penetration welding treatment is designed for the special characteristics of the high-depth butt joints between the forged steel parts, in order to form a high-quality weld and eliminate residual stress inside the weld.

[0025] In step 5, the stress removal treatment is to heat the shaping tooling together with the integral bending forged steel part to 300-350°C by means of nozzle or pipeline heating, and then keep it at that temperature for 2-3 hours to remove hydrogen. The hydrogen-free treated workpiece is placed into a heating furnace and heated to 540-580℃ at a heating rate of ≤70℃ / h. After holding at this temperature for at least 8 hours, the stress is eliminated.

[0026] The above-mentioned technical measures are designed for the special characteristics of large workpiece structure and large amount of welding work. When the workpiece cannot be put into the furnace for stress relief immediately after welding, hydrogen removal treatment is carried out outside the furnace first, and then it is transferred into the furnace for stress relief treatment to eliminate residual stress in the weld and ensure welding quality.

[0027] The beneficial technical effects of the present invention are as follows: The above-mentioned technical measures are aimed at the design structure of the cable saddle formed by forging steel parts. Due to the special characteristics of the forging steel part structure itself and the arc-shaped arch of the bottom plate of the cable saddle groove, the forging steel part forming the bottom plate of the saddle groove is formed by segmented butt joint assembly structure, without relying on large-sized integral forging steel parts. On the one hand, it is beneficial to reduce the technical difficulty of manufacturing cable saddles with forging steel parts; on the other hand, it is beneficial to ensure the forging quality of forging steel parts; on the third hand, it is beneficial to control the manufacturing cost of cable saddles; and on the fourth hand, it makes the design of manufacturing cable saddles with forging steel parts more practical and feasible.

[0028] Based on the relatively independent segmentation of the forged steel parts of the formed saddle groove bottom plate, the above-mentioned technical measures use a shaping fixture to clamp and position the bending trajectory of the two relative forged steel parts that need to be combined together. This ensures that the overall linear profile of the combined forged steel parts can reliably meet the arched arc structure of the saddle groove bottom plate, while ensuring the precise forming of the butt joint between the forged steel parts. This prevents relative deformation of the butt joint during the welding process, which is beneficial for high-quality welding and ensures that the machining allowance of the bottom surface of the forged steel parts is not affected by welding.

[0029] The above-mentioned technical measures, by uniformly and reliably preheating and heat preservation during welding of the forged steel parts to be welded on the shaped tooling, and reliably relieving stress after welding, enable the weld between the forged steel parts to be formed with high quality, eliminate internal structural stress defects, and meet the internal quality requirements of the forged steel parts.

[0030] Therefore, the above-mentioned technical measures form the saddle groove bottom plate with an arc-shaped arch structure by welding multiple sections of forged steel. The formed saddle groove bottom plate has reliable quality and excellent mechanical properties. The forming method is simple and easy to implement, which helps to reduce the amount of machining work and material waste. Compared with the cutting and shaping method of large-size forged steel parts, the above-mentioned technical measures are more efficient, economical and practical, with significant economic benefits. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of a process state according to the present invention.

[0032] Figure 2 for Figure 1 A schematic diagram of a blunt-edge butt joint.

[0033] Figure 3 for Figure 1 A schematic diagram of the arc extinguishing unit in the diagram.

[0034] Figure 4 This is a schematic diagram of another process state according to the present invention.

[0035] The symbols in the diagram have the following meanings: 1—Forged steel part one; 2—Forged steel part two; 3—Shaping tool; 31—Longitudinal rib plate; 32—Transverse rib plate; 4—Standard plate; 5—Heating tube; 6—Arc-starting side plate; 7—Arc-extinguishing side plate; 8—Arc-extinguishing bottom plate; 9—Butt joint; A—Integral bending forged steel part; B—Forged steel part three; a—Butt joint bevel angle. Detailed Implementation

[0036] This invention relates to a method for forming cable saddles for suspension bridges, specifically a welding method for a forged and welded cable saddle, and more precisely, a method for welding the saddle groove bottom plate of a forged and welded cable saddle using forged steel parts. The main technical solution of this invention will be specifically described below with reference to several embodiments. Embodiment 1 is illustrated in conjunction with the accompanying drawings—that is… Figure 1 , Figure 2 , Figure 3 and Figure 4 The technical solution of the present invention is clearly and in detail explained; although other embodiments are not shown in separate drawings, their main structure can still be referred to the drawings of Embodiment 1.

[0037] It should be noted that the accompanying drawings of this invention are schematic, and unnecessary details have been simplified in order to clarify the technical objectives of this invention, so as to avoid obscuring the technical solutions contributed by this invention to the prior art.

[0038] Example 1 This invention relates to a method for welding the saddle groove bottom plate of a forged and welded cable saddle using forged steel components. See [link to relevant documentation]. Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, it includes three forged steel parts used as forming saddle groove bottom plates, namely forged steel part 1, forged steel part 2 and forged steel part 3B. Each forged steel part is obtained after passing ultrasonic flaw detection and tempering heat treatment.

[0039] The welding method of this invention also relies on a shaping fixture 3, which mainly consists of multiple longitudinal ribs 31 and multiple transverse ribs 32 forming a frame structure in a longitudinal and transverse interwoven manner. The longitudinal ribs 31 are spaced apart along the width direction corresponding to the bottom plate of the saddle groove. Each longitudinal rib 31 has a straight edge on its bottom side and an arched edge structure on its top side, the outline of which basically conforms to the arcuate contour of the saddle groove. The transverse ribs 32 are divided into multiple groups, each group of transverse ribs 32 being spaced apart along the length direction corresponding to the bottom plate of the saddle groove. Each transverse rib 32 in each group is arranged sequentially between adjacent longitudinal ribs 31 along the width direction. The entire shaping fixture 3 has a flat bottom structure and an arched top structure adapted to the arcuate contour of the saddle groove. In order to facilitate the preheating and heat preservation of the forged steel parts to be welded by the shaping fixture 3, multiple sets of heating tube perforations are opened near the top side of each butt joint in the shaping fixture 3. Usually, there are two sets corresponding to each butt joint, located on the left and right sides directly below the butt joint.

[0040] The welding method of the present invention specifically includes the following process steps: Step 1. On the forged steel part 1 and forged steel part 2 to be docked, respectively, a blunt edge welding bevel is machined. The blunt edge arc of the blunt edge welding bevel is about R10mm and the thickness is about 5mm. The angle between the bevel wall of the blunt edge welding bevel and the vertical surface of the blunt edge is about 1°. The surface of the blunt edge welding bevel is qualified by surface magnetic particle inspection. The forged steel parts 1 and 2 to be joined are fixed to a common shaping fixture 3 by segment welding. Forged steel parts 1 and 2 are joined on the shaping fixture 3 with matching blunt-edged weld bevels, so that the blunt edges of forged steel parts 1 and 2 are in contact with each other, essentially without gaps. An approximately 2° bevel angle α is formed between the weld bevels, resulting in a U-shaped blunt-edged weld 9 between forged steel parts 1 and 2, narrow at the bottom and wide at the top, with no gap at the bottom and a depth of approximately 500mm (see [reference]). Figure 2 As shown), forged steel parts 1 and 2 are arranged according to the designed bending structure and segmentally welded to the arch of the shaping fixture 3 (see...). Figure 1 (as shown) To prevent burn-through at the butt joint 9 during subsequent welding, the above-mentioned forged steel parts 1 and 2 are fixed at the top of the shaping fixture 3. A burn-through liner can be set at the bottom of the butt joint 9 between the forged steel parts 1 and 2 and the shaping fixture 3 to improve the welding quality at the root of the weld. The above-mentioned segment welding fixation involves welding each welding position of forged steel part 1 / forged steel part 2 with double-sided fillet welds. The length of each weld segment is approximately 300mm, and the spacing between two adjacent weld segments is approximately 150mm. In the above structure, in order to improve the welding quality at the butt joint 9, an arc-starting unit extending outward by about 150mm and forming an extension for the butt joint 9 is welded and fixed to the surfaces of the forged steel part 1 and forged steel part 2 at one end of the butt joint 9. An arc-extinguishing unit extending outward by about 150mm and forming an extension for the butt joint 9 is connected to the forged steel part 1 and forged steel part 2 at the other end of the butt joint 9 (see...). Figure 1 and Figure 3 (as shown) The aforementioned arc-initiating unit mainly consists of arc-initiating side plates 6 connected to the corresponding surfaces of forged steel part 1 and forged steel part 2, and an arc-initiating base plate connected between the bottoms of the two arc-initiating side plates 6. At the corresponding ends of the butt joint 9, the arc-initiating unit extends outward in a U-shape. In the arc-initiating unit, the inner surfaces of the two arc-initiating side plates 6 are basically flush with the bevel of the forged steel part. Multiple mounting plates are connected between the back surfaces of the two arc-initiating side plates 6 and the forged steel part to support the connection strength of the corresponding arc-initiating side plates 6 on the forged steel part. The aforementioned arc-initiating side plates 6 and arc-initiating base plate are formed from steel plates with a thickness of approximately 20mm. The aforementioned arc-extinguishing unit mainly consists of arc-extinguishing side plates 7 connected to the corresponding surfaces of forged steel part 1 and forged steel part 2, and an arc-extinguishing base plate 8 connected between the bottoms of the two arc-extinguishing side plates 7. The corresponding ends of the butt joint 9 extend outward in a U-shaped structure. In the arc-extinguishing unit, the inner surfaces of the two arc-extinguishing side plates 7 are basically flush with the bevel of the forged steel part. Multiple mounting plates 4 are connected between the back surfaces of the two arc-extinguishing side plates 7 and the forged steel part to support the connection strength of the corresponding arc-extinguishing side plates 7 on the forged steel part. The aforementioned arc-extinguishing side plates 7 and arc-extinguishing base plate are formed from steel plates with a thickness of approximately 20 mm. Step 2. When the forged steel part 1 and the forged steel part 2 are fixed on the shaping fixture 3 and the arc-starting unit and arc-extinguishing unit are formed, clean the surface of the butt joint 9 (including the welding bevel and the arc-starting and arc-extinguishing units), especially removing oil and rust. The shaping fixture 3, together with the fixed forged steel part 1 and forged steel part 2, is sent into the heating furnace as a whole. The workpiece is heated to 300°C in the heating furnace at a heating rate of about 60°C / h, and then held at that temperature for about 2.5h to complete the preheating treatment of forged steel part 1 and forged steel part 2 before welding. While preheating the workpiece, the flux should be dried. After drying the flux at a temperature of about 300°C for about 2.5 hours, it should be placed in an insulated container for storage. Step 3. Transfer the preheated forged steel part 1 and forged steel part 2 to the welding station. Insert heating tubes 5 into the two sets of heating tube insertion holes below the butt joint 9. Preheat and keep the butt joint 9 between forged steel part 1 and forged steel part 2 through the heating tubes 5. The preheating and keeping temperature is about 250℃. Step 4. Use a narrow-gap submerged arc automatic welding machine to perform penetration welding on the butt joint 9 between forged steel part 1 and forged steel part 2. The specific welding operation is as follows: Before welding, clean the welding bevel of butt joint 9 thoroughly; First, perform the bottom layer welding, then the intermediate layer welding, and finally the top layer welding. The welding current for the root pass is approximately 480A, the welding voltage is approximately 30V, and the welding speed is approximately 500mm / min. The welding current for the intermediate layer and the cover layer is approximately 530A, the welding voltage is approximately 32V, and the welding speed is approximately 330mm / min. During the welding process, for each weld layer with a bevel width of less than 30mm (usually the first half of the base layer and the middle layer), welding is performed by one pass on the left and one pass on the right; for each weld layer with a bevel width exceeding 30mm (usually the second half of the middle layer and the cover layer), welding is performed by one pass on the left, one pass in the middle and one pass on the right. During the welding process, the flux ignites the arc at the arc-ignition unit outside the butt joint 9, and the flux extinguishes the arc at the arc-extinguishing unit outside the butt joint 9. During the welding process, after each weld layer is completed, the weld seam is cleaned to remove slag and flux. Follow the welding operation described above until forged steel part 1 and forged steel part 2 are welded together on the shaping fixture 3 to form an integral bent forged steel part A. Step 5. Heat the shaping fixture 3 and the integral bent forged steel part A to about 330°C using a nozzle or pipe heating method, and hold at that temperature for about 2.5 hours to remove hydrogen. The hydrogen-free treated workpiece is sent into the heating furnace as a whole and heated to about 560°C at a heating rate of about 60°C / h. After holding at this temperature for about 8 hours, it undergoes stress relief heat treatment. Then, it is cooled with the furnace to about 200°C at a cooling rate of about 50°C / h and lifted out. Ultrasonic testing was performed on the integrally bent forged steel part A. After passing the test, integrally bent forged steel part A and the remaining forged steel part B to be welded were designated as the two forged steel parts to be welded (integrally bent forged steel part A was designated as the new forged steel part one, and forged steel part B was designated as the new forged steel part two, see [reference]). Figure 4 (As shown), repeat steps 1 to 5 to form a new integral bent forging steel part on the shaping fixture 3; After all three sections of forged steel are welded and the last weld is stress-relieved, and the final integral bent forged steel part passes the flaw detection test, the forged steel parts that make up the saddle groove bottom plate are welded. Then the shaping tooling is removed, and the integral bent forged steel part is transferred to subsequent machining.

[0041] Example 2 The present invention relates to a method for welding the saddle groove bottom plate of a forged and welded cable saddle with forged steel parts, comprising two forged steel parts used as forming the saddle groove bottom plate, namely forged steel part one and forged steel part two. Each forged steel part is obtained after passing ultrasonic flaw detection and tempering heat treatment.

[0042] The welding method of this invention also relies on a shaped fixture, which mainly consists of multiple longitudinal ribs and multiple transverse ribs forming a frame structure in a longitudinal and transverse interwoven pattern. The longitudinal ribs are spaced apart along the width direction corresponding to the bottom plate of the saddle groove. Each longitudinal rib has a straight edge on its bottom side and an arched edge on its top side, the outline of which basically conforms to the arcuate contour of the saddle groove. The transverse ribs are divided into multiple groups, each group arranged spaced apart along the length direction corresponding to the bottom plate of the saddle groove. Each transverse rib in each group is arranged sequentially between adjacent longitudinal ribs along the width direction. The entire shaped fixture has a flat bottom and an arched top adapted to the arcuate contour of the saddle groove. To facilitate preheating and heat preservation of the forged steel parts to be welded using the shaped fixture, multiple sets of heating pipe perforations are opened near the top side of each butt joint, typically two sets for each butt joint, located on the left and right sides directly below the butt joint.

[0043] The welding method of the present invention specifically includes the following process steps: Step 1. On the forged steel parts 1 and 2 to be docked, respectively, a blunt edge welding bevel is machined. The blunt edge arc of the blunt edge welding bevel is about R10mm and the thickness is about 6mm. The angle between the bevel wall and the perpendicular surface of the blunt edge is about 1°. The surface of the blunt edge welding bevel is inspected by surface magnetic particle testing and passes the inspection. The forged steel parts 1 and 2 to be joined are fixed on a common shaping fixture by segment welding. The forged steel parts 1 and 2 are joined on the shaping fixture with matching blunt edge welding bevels, so that the blunt edges of the forged steel parts 1 and 2 are in contact with each other with almost no gap. The welding bevels form a butt joint bevel angle of about 2°, that is, a U-shaped blunt edge butt joint with a narrow bottom and wide opening, no gap at the bottom, and a depth of about 520mm is formed between the forged steel parts 1 and 2. In this way, the forged steel parts 1 and 2 are arranged according to the designed curved structure and fixed at the arch of the shaping fixture by segment welding. To prevent the weld root from being burned through during subsequent welding, the above-mentioned forged steel parts 1 and 2 are fixed on the top of the shaping fixture. Therefore, an anti-burn-through gasket can be set between the bottom of the butt joint between forged steel parts 1 and 2 and the shaping fixture to improve the welding quality at the weld root. The above-mentioned segment welding fixation involves welding each welding position of forged steel part one / forged steel part two with double-sided fillet welds. The length of each weld segment is approximately 250mm, and the spacing between two adjacent weld segments is approximately 100mm. In the above structure, in order to improve the welding quality at the joint, an arc-starting unit extending outward by about 140mm is welded and fixed on the surface of the forged steel parts 1 and 2 at one end of the joint, and an arc-extinguishing unit extending outward by about 140mm is connected to the forged steel parts 1 and 2 at the other end of the joint. The aforementioned arc-starting unit mainly consists of arc-starting side plates connected to the corresponding surfaces of forged steel part one and forged steel part two, and an arc-starting base plate connected between the bottoms of the two arc-starting side plates. It extends outward in a U-shape at the corresponding ends of the butt joint. In the arc-starting unit, the inner surfaces of the two arc-starting side plates are basically flush with the bevel of the forged steel part. Multiple mounting plates are connected between the back surfaces of the two arc-starting side plates and the forged steel part to support the connection strength of the corresponding arc-starting side plates on the forged steel part. The aforementioned arc-starting side plates and arc-starting base plates are formed from steel plates with a thickness of approximately 22mm. The aforementioned arc-extinguishing unit mainly consists of arc-extinguishing side plates connected to the corresponding surfaces of forged steel part one and forged steel part two, and an arc-extinguishing base plate connected between the bottoms of the two arc-extinguishing side plates. The corresponding ends of the butt joint extend outward in a U-shaped structure. In the arc-extinguishing unit, the inner surfaces of the two arc-extinguishing side plates are basically flush with the bevel of the forged steel part. Multiple mounting plates are connected between the back surfaces of the two arc-extinguishing side plates and the forged steel part to support the connection strength of the corresponding arc-extinguishing side plates on the forged steel part. The aforementioned arc-extinguishing side plates and arc-extinguishing base plates are formed from steel plates with a thickness of approximately 22mm. Step 2. Once forged steel part one and forged steel part two are fixed on the shaping fixture and form the arc-starting unit and arc-extinguishing unit, clean the surface of the butt joint (including the welding bevel area and the arc-starting unit and arc-extinguishing unit), especially removing oil and rust. The shaping fixture, together with the fixed forged steel parts one and two, is sent into the heating furnace. The workpiece is heated to 320°C in the heating furnace at a heating rate of about 70°C / h, and then held at that temperature for about 2 hours to complete the preheating treatment of forged steel parts one and two before welding. While preheating the workpiece, the flux should be dried. After drying the flux at about 320°C for about 2 hours, it should be placed in an insulated container for storage. Step 3. Transfer the preheated forged steel parts 1 and 2 to the welding station. Insert heating tubes into the two sets of heating tube insertion holes below the butt joint. Preheat and insulate the butt joint between forged steel parts 1 and 2 through the heating tubes. The preheating and insulation temperature is about 260℃. Step 4. Use a narrow-gap submerged arc welding machine to perform a full penetration weld on the butt joint between forged steel part one and forged steel part two. The specific welding operation is as follows: Before welding, the welding bevel of the butt joint should be thoroughly cleaned. First, perform the bottom layer welding, then the intermediate layer welding, and finally the top layer welding. The welding current for the root pass is approximately 490A, the welding voltage is approximately 32V, and the welding speed is approximately 520mm / min. The welding current for the intermediate layer and the cover layer is approximately 540A, the welding voltage is approximately 34V, and the welding speed is approximately 340mm / min. During the welding process, for each weld layer with a bevel width of less than 30mm (usually the first half of the base layer and the middle layer), welding is performed by one pass on the left and one pass on the right; for each weld layer with a bevel width exceeding 30mm (usually the second half of the middle layer and the cover layer), welding is performed by one pass on the left, one pass in the middle and one pass on the right. During the welding process, the flux initiates the arc at the arc-initiating unit outside the butt joint, and the flux extinguishes the arc at the arc-extinguishing unit outside the butt joint. During the welding process, after each weld layer is completed, the weld seam is cleaned to remove slag and flux. Follow the welding operation described above until forged steel part one and forged steel part two are welded together on the shaping fixture to form an integral bent forged steel part A; Step 5. Heat the shaping tooling and the integral bending forged steel part to about 350°C using a nozzle or pipe heating method, and hold it at that temperature for about 2 hours to remove hydrogen. The hydrogen-free treated workpiece is sent into the heating furnace as a whole and heated to about 580°C at a heating rate of about 70°C / h. After holding at this temperature for about 10 hours, it undergoes stress relief heat treatment. Then, it is cooled with the furnace to about 200°C at a cooling rate of about 60°C / h and lifted out. Ultrasonic testing is used to inspect the integral bent forged steel parts. After the inspection is passed, the forged steel parts that make up the saddle groove bottom plate are welded. Then the shaping tooling is removed, and the integral bent forged steel parts are transferred to subsequent machining processes.

[0044] Example 3 This invention relates to a method for welding the saddle groove bottom plate of a forged and welded cable saddle using forged steel parts. The method includes four forged steel parts used as forming the saddle groove bottom plate, namely forged steel part one, forged steel part two, forged steel part three, and forged steel part four. Each forged steel part is obtained after passing ultrasonic flaw detection and tempering heat treatment.

[0045] The welding method of this invention also relies on a shaped fixture, which mainly consists of multiple longitudinal ribs and multiple transverse ribs forming a frame structure in a longitudinal and transverse interwoven pattern. The longitudinal ribs are spaced apart along the width direction corresponding to the bottom plate of the saddle groove. Each longitudinal rib has a straight edge on its bottom side and an arched edge on its top side, the outline of which basically conforms to the arcuate contour of the saddle groove. The transverse ribs are divided into multiple groups, each group arranged spaced apart along the length direction corresponding to the bottom plate of the saddle groove. Each transverse rib in each group is arranged sequentially between adjacent longitudinal ribs along the width direction. The entire shaped fixture has a flat bottom and an arched top adapted to the arcuate contour of the saddle groove. To facilitate preheating and heat preservation of the forged steel parts to be welded using the shaped fixture, multiple sets of heating pipe perforations are opened near the top side of each butt joint, typically two sets for each butt joint, located on the left and right sides directly below the butt joint.

[0046] The welding method of the present invention specifically includes the following process steps: Step 1. On the forged steel parts 1 and 2 to be docked, respectively, a blunt edge welding bevel is machined. The blunt edge arc of the blunt edge welding bevel is about R10mm and the thickness is about 4mm. The angle between the bevel wall and the perpendicular surface of the blunt edge is about 1°. The surface of the blunt edge welding bevel is qualified by surface magnetic particle inspection. The forged steel parts 1 and 2 to be joined are fixed on a common shaping fixture by segment welding. The forged steel parts 1 and 2 are joined on the shaping fixture with matching blunt edge welding bevels, so that the blunt edges of the forged steel parts 1 and 2 are in contact with each other with almost no gap. The welding bevels form a butt joint bevel angle of about 2°, that is, a U-shaped blunt edge butt joint with a narrow bottom and wide opening, no gap at the bottom, and a depth of about 450mm is formed between the forged steel parts 1 and 2. In this way, the forged steel parts 1 and 2 are arranged according to the designed curved structure and fixed at the top of the shaping fixture by segment welding. To prevent burn-through at the joint of the forged steel parts 1 and 2 during subsequent welding, an anti-burn-through gasket can be placed between the bottom of the joint between the forged steel parts 1 and 2 and the shaping fixture to improve the welding quality at the root of the weld. The above-mentioned segment welding fixation involves welding each welding position of forged steel part one / forged steel part two with double-sided fillet welds. The weld length of each welding position is approximately 350mm, and the spacing between two adjacent welding positions is approximately 150mm. In the above structure, in order to improve the welding quality at the joint, an arc-starting unit extending outward by about 150mm is welded and fixed on the surface of the forged steel parts 1 and 2 at one end of the joint, and an arc-extinguishing unit extending outward by about 150mm is connected to the forged steel parts 1 and 2 at the other end of the joint. The aforementioned arc-starting unit mainly consists of arc-starting side plates connected to the corresponding surfaces of forged steel part one and forged steel part two, and an arc-starting base plate connected between the bottoms of the two arc-starting side plates. It extends outward in a U-shape at the corresponding ends of the butt joint. In the arc-starting unit, the inner surfaces of the two arc-starting side plates are basically flush with the bevel of the forged steel part. Multiple mounting plates are connected between the back surfaces of the two arc-starting side plates and the forged steel part to support the connection strength of the corresponding arc-starting side plates on the forged steel part. The aforementioned arc-starting side plates and arc-starting base plates are formed from steel plates with a thickness of approximately 20mm. The aforementioned arc-extinguishing unit mainly consists of arc-extinguishing side plates connected to the corresponding surfaces of forged steel part one and forged steel part two, and an arc-extinguishing base plate connected between the bottoms of the two arc-extinguishing side plates. The corresponding ends of the butt joint extend outward in a U-shape. In the arc-extinguishing unit, the inner surfaces of the two arc-extinguishing side plates are basically flush with the bevel of the forged steel part. Multiple mounting plates are connected between the back surfaces of the two arc-extinguishing side plates and the forged steel part to support the connection strength of the corresponding arc-extinguishing side plates on the forged steel part. The aforementioned arc-extinguishing side plates and arc-extinguishing base plates are formed from steel plates with a thickness of approximately 20mm. Step 2. Once forged steel part one and forged steel part two are fixed on the shaping fixture and form the arc-starting unit and arc-extinguishing unit, clean the surface of the butt joint (including the welding bevel area and the arc-starting unit and arc-extinguishing unit), especially removing oil and rust. The shaping fixture, together with the fixed forged steel parts one and two, is sent into the heating furnace. The workpiece is heated to 280°C in the heating furnace at a heating rate of about 65°C / h, and then held at that temperature for about 3 hours to complete the preheating treatment of forged steel parts one and two before welding. While preheating the workpiece, the flux should be dried. After drying the flux at a temperature of about 280°C for about 3 hours, it should be placed in an insulated container for storage. Step 3. Transfer the preheated forged steel parts 1 and 2 to the welding station. Insert heating tubes into the two sets of heating tube insertion holes below the butt joint. Preheat and insulate the butt joint between forged steel parts 1 and 2 through the heating tubes. The preheating and insulation temperature is about 240℃. Step 4. Use a narrow-gap submerged arc welding machine to perform a full penetration weld on the butt joint between forged steel part one and forged steel part two. The specific welding operation is as follows: Before welding, the welding bevel of the butt joint should be thoroughly cleaned. First, perform the bottom layer welding, then the intermediate layer welding, and finally the top layer welding. The welding current for the root pass is approximately 470A, the welding voltage is approximately 28V, and the welding speed is approximately 480mm / min. The welding current for the intermediate layer and the cover layer is approximately 520A, the welding voltage is approximately 30V, and the welding speed is approximately 320mm / min. During the welding process, for each weld layer with a bevel width of less than 30mm (usually the first half of the base layer and the middle layer), welding is performed by one pass on the left and one pass on the right; for each weld layer with a bevel width exceeding 30mm (usually the second half of the middle layer and the cover layer), welding is performed by one pass on the left, one pass in the middle and one pass on the right. During the welding process, the welding arc is initiated at the arc-initiating unit outside the butt joint, and the welding arc is extinguished at the arc-extinguishing unit outside the butt joint. During the welding process, after each weld layer is completed, the weld seam is cleaned to remove slag and flux. Follow the welding operation described above until forged steel part one and forged steel part two are welded together on the shaping fixture to form an integral bent forged steel part A; Step 5. Heat the shaping fixture and the integral bending forged steel part A to about 300°C using a nozzle or pipe heating method, and then keep it at that temperature for about 3 hours to remove hydrogen. The hydrogen-free treated workpiece is sent into the heating furnace as a whole and heated to about 540°C at a heating rate of about 65°C / h. After holding at that temperature for about 9.5 hours, it is subjected to stress relief treatment. Then, it is cooled with the furnace to about 200°C at a cooling rate of about 65°C / h and then lifted out. Ultrasonic testing is performed on the integrally bent forged steel part A. After the testing is qualified, the integrally bent forged steel part A and the remaining forged steel part three B to be welded are used as the two forged steel parts to be welded (the integrally bent forged steel part A is used as the new forged steel part one, and the forged steel part three B is used as the new forged steel part two). Steps 1 to 5 are repeated to form a new integrally bent forged steel part C on the shaping fixture. Ultrasonic testing is performed on the integrally bent forged steel part C. After the testing is qualified, the integrally bent forged steel part C and the remaining forged steel part 4D to be welded are used as the two forged steel parts to be welded (the integrally bent forged steel part C is used as the new forged steel part one, and the forged steel part 4D is used as the new forged steel part two). Steps 1 to 5 are repeated to form a new integrally bent forged steel part on the shaping fixture. After all four sections of forged steel parts have been welded and the last weld has undergone stress relief treatment, and the final new integral bent forged steel part has passed the flaw detection test, the forged steel parts that make up the saddle groove bottom plate have been welded. Then the shaping tooling is removed, and the integral bent forged steel part is transferred to subsequent machining processing.

[0047] The above embodiments are only used to illustrate the present invention and are not intended to limit it.

[0048] Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications can still be made to the above embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the present invention.

Claims

1. A forged and welded cable saddle welding method, comprising at least two forged steel parts used as the bottom plate of the forming cable saddle groove; Its features are, The welding method includes the following process steps: Step 1. Fix the forged steel parts 1 and 2 to be joined on a common shaping fixture, forming a joint between the forged steel parts 1 and 2 with a narrow bottom and wide opening and no gap at the bottom; The forged steel parts 1 and 2 at one end of the joint are connected to an outwardly extending arc-guiding unit that elongates the joint. The arc-guiding unit mainly consists of an arc-guiding side plate connected to the corresponding surfaces of the forged steel parts 1 and 2, and an arc-guiding bottom plate connected between the bottoms of the two arc-guiding side plates. It extends outward in a U-shape at the end of the joint. The forged steel parts 1 and 2 at the other end of the joint are connected to an outwardly extending arc-extinguishing unit that elongates the joint. The arc-extinguishing unit mainly consists of an arc-extinguishing side plate connected to the corresponding surfaces of the forged steel parts 1 and 2, and an arc-extinguishing bottom plate connected between the bottoms of the two arc-extinguishing side plates. It extends outward in a U-shaped structure at the end of the joint. The shaping fixture has two sets of through holes for inserting heating tubes at the top side of the butt joint between forged steel part one and forged steel part two. The through holes for these two sets of heating tubes are located on the left and right sides directly below the butt joint. Step 2. The shaping fixture, together with the fixed forged steel part one and forged steel part two, is sent into the heating furnace for preheating treatment before welding. Step 3. Transfer the preheated forged steel parts 1 and 2 to the welding station, and perform heat insulation treatment on the butt joint between forged steel parts 1 and 2. The heat insulation treatment involves inserting corresponding heating pipes into the two sets of heating pipe perforations below the joint. Step 4. Perform penetration welding at the joint until forged steel part one and forged steel part two are welded into an integral bent forged steel part on the shaping fixture; Step 5. Perform stress-relieving heat treatment and weld flaw detection on the integral bent forged steel part; If the flaw detection is qualified, and there are other forged steel parts to be welded, repeat steps 1 to 5 to form a new integral bent forged steel part on the shaping tooling. If the flaw detection is qualified, and all the forged steel parts constituting the bottom plate of the cable saddle groove are welded, the shaping tooling is removed, and the whole bent forged steel part is transferred to subsequent machining processing.

2. The forged and welded cable saddle welding method according to claim 1, characterized in that: In step 1, the first forged steel part and the second forged steel part are fixed to the shaping fixture by segment welding. Each welding position of the segment weld adopts a double-sided fillet weld, the length of each segment weld is 250-350mm, and the spacing between two adjacent segments weld is 100-150mm.

3. The forged and welded cable saddle welding method according to claim 1 or 2, characterized in that: The shaping tooling mainly consists of multiple longitudinal ribs and multiple transverse ribs forming a frame structure in a longitudinal and transverse interwoven structure; Multiple longitudinal ribs are arranged at intervals in the width direction corresponding to the bottom plate of the saddle groove; Multiple transverse ribs are divided into multiple groups. The transverse ribs in each group are arranged at intervals along the length direction corresponding to the bottom plate of the saddle groove. Each transverse rib in each group is arranged sequentially between two adjacent longitudinal ribs along the width direction. The bottom of the shaping fixture is a flat bottom structure, and the top is an arched structure adapted to the arc-shaped contour of the saddle groove. The forged steel parts one and two are arranged according to the designed bending structure and fixed at the arch of the shaping fixture.

4. The forged and welded cable saddle welding method according to claim 1, characterized in that: In step 1, the butt joint formed between the first forged steel part and the second forged steel part is a U-shaped blunt-edge butt joint. The blunt edge thickness of the butt joint is 4–6 mm.

5. The forged and welded cable saddle welding method according to claim 4, characterized in that: At the bottom of the butt joint between the first forged steel part and the second forged steel part, an anti-burn-through liner is provided between the shaping fixture and the first forged steel part and the second forged steel part.

6. The forged and welded cable saddle welding method according to claim 1, characterized in that: In step 2, the preheating treatment before welding involves heating the entire workpiece in a heating furnace at a heating rate of ≤70℃ / h to 280~320℃ and then holding it at that temperature for 2~3h. After the flux is dried at 280-320℃ for 2-3 hours, it is placed in an insulated container for storage.

7. The forged and welded cable saddle welding method according to claim 1, characterized in that: In step 4, the penetration welding process is performed using a narrow-gap submerged arc automatic welding machine; The welding current for the root pass is 470–490A, the welding voltage is 28–32V, and the welding speed is 480–520mm / min. The welding current for the remaining layers is 520–540A, the welding voltage is 30–34V, and the welding speed is 320–340mm / min. During the welding process, for each weld layer with a bevel width of less than 30mm, welding is performed by welding one pass on the left and one pass on the right; for each weld layer with a bevel width exceeding 30mm, welding is performed by welding one pass on the left, one pass in the middle, and one pass on the right. During the welding process, the flux initiates the arc at the arc-initiating unit outside the butt joint, and the flux extinguishes the arc at the arc-extinguishing unit outside the butt joint. During the welding process, after each weld layer is completed, the weld seam is cleaned to remove slag and flux residue.

8. The forged and welded cable saddle welding method according to claim 1, characterized in that: In step 5, the stress removal treatment is to heat the shaping tooling together with the integral bending forged steel part to 300-350°C by means of nozzle or pipeline heating, and then keep it at that temperature for 2-3 hours to remove hydrogen. The hydrogen-free treated workpiece is placed into a heating furnace and heated to 540-580℃ at a heating rate of ≤70℃ / h. After holding at this temperature for at least 8 hours, it undergoes stress relief heat treatment.

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