A high-strength steel austenitic fusion angle weld uncleaned welding method

Abstract

The application provides a high-strength steel austenitic fusion angle weld non-clear root welding method. The method is characterized in that an L-shaped welding positioning plug is used to plug the fusion welding angle weld of the austenitic high-strength steel, the plug is used to position the web groove, the uniformity of the welding gap is ensured, the re-heating effect of the carbon arc air gouging on the base material is avoided, the deformation caused by the heating effect and the root cleaning process are reduced, and the technical problem of unstable welding quality of the austenitic high-strength steel is solved. Since the L-shaped welding positioning plug clamping end adjusts the assembly gap of the angle weld groove and meets the uniform size requirement, the strength and the welding quality of the weld are ensured, the high-strength steel austenitic fusion angle weld non-clear root welding method can avoid the unstable welding quality, the large welding deformation and the influence of the whole rigid fixing structure caused by the traditional welding, and the manufacturing quality and the manufacturing precision of the whole rigid fixing structure are affected. The application is suitable for the high-strength steel austenitic fusion angle weld non-clear root welding method.

Description

Technical Field

[0001] This invention relates to the field of welding technology, and more particularly to the welding of steel structures with high rigidity and strong restraint fixed support. Specifically, it relates to a method for welding high-strength steel austenitic penetration fillet welds without root removal. Background Technology

[0002] High-rigidity, strongly restrained fixed supports are one of the most important structural components in steel structure construction. The entire system and structure rely on them for support, thereby ensuring its stability. The supports adopt a high-rigidity structure, and the upper and lower connections are made by welding. The welds are strongly restrained welds, which must ensure structural strength and weld quality while controlling the welding deformation of the entire structure.

[0003] In typical steel structure support and fixation, the upper part is welded to the pier structure, and the lower part of the pier is welded to the embedded parts. The welding between the lower part of the pier and the embedded parts is a full penetration fillet weld. The fillet weld is welded on one side and the other side is carbon arc gouged. Inevitably, a carbonized layer is generated on the surface of the gouged bevel, which needs to be removed by grinding with a grinding wheel. Carbon arc gouging adds an extra welding process. The heat input of the gouging operation is large, and the pier is an internally enclosed structure with a small space, making the carbon arc gouging operation difficult, thus increasing the welding deformation and quality risks. Summary of the Invention

[0004] To improve welding quality, this invention proposes a method for welding high-strength austenitic full penetration fillet welds without root cleaning. This method involves inserting an "L"-shaped welding positioning block into the full penetration fillet weld of austenitic high-strength steel. This "L"-shaped welding positioning block is used to position the web bevel, ensuring the uniformity of the weld gap and avoiding the re-heating effect of carbon arc gouging on the base material. This reduces deformation caused by heat and the need for root cleaning, relatively reducing the amount of welding material filler. Utilizing the advantages of austenitic welding materials—good plasticity, toughness, and stable quality—this method reduces defects and solves the technical problem of unstable welding quality in austenitic high-strength steel.

[0005] The solution adopted by this invention to solve the technical problem is: a method for welding high-strength steel austenitic penetration fillet welds without root removal, which is achieved through the following steps: Step 1: Analyze the steel structure panel to be welded and test the mechanical properties and chemical composition of the constituent materials of the steel structure panel.

[0006] Step 2: Based on the thickness and specifications of the steel structure panel to be welded, perform single-sided V-shaped beveling on the web plate that requires fillet welding. The beveling is processed according to the welding space and the accessibility of single-sided welding.

[0007] Step 3: Use an "L"-shaped welding positioning block to position the web bevel. The "L"-shaped welding positioning block consists of a mating end and a gap end that are perpendicular to each other. The gap end fits the bevel assembly gap, and the mating end fits the web. To ensure the uniformity of the bevel assembly gap and the timely removal of the "L"-shaped welding positioning block, the gap end of the "L"-shaped welding positioning block adopts a sloping structure. The thickness of the sloping structure includes the size of the bevel gap. During the root pass welding process, the presence of the "L"-shaped welding positioning block in the bevel gap ensures uniform welding shrinkage. The tensile strength of the "L"-shaped welding positioning block material is lower than that of the base material being welded, thus ensuring that the "L"-shaped welding positioning block can be removed smoothly.

[0008] Step 4: Select matching welding materials based on the composition of the steel structure panel and web, preliminarily determine the welding materials, current, voltage, and speed requirements, conduct welding tests, and continue welding until the relevant parameters meet the requirements of the weld after welding, and then use this as the welding method for penetration fillet welds.

[0009] The steel structure panels and webs described in this invention are both austenitic high-strength steel, and the method described in this invention is particularly suitable for welding fillet welds made of austenitic high-strength steel without root removal.

[0010] The positive effects are that, because the "L"-shaped welding positioning plug of this invention adjusts the assembly gap of the fillet weld bevel at the clamping end to meet the uniform size requirements, it ensures the weld width, thereby guaranteeing weld strength and welding quality. The method described in this invention for high-strength steel austenitic penetration fillet welds without root removal avoids the unstable welding quality and large welding deformation associated with traditional welding, which can affect the fabrication quality and precision of the entire rigid fixed structure. This method is simple to operate and suitable for use as a method for high-strength steel austenitic penetration fillet welds without root removal. Attached Figure Description

[0011] Appendix Figure 1 Diagram of the beveling: Appendix Figure 2 Schematic diagram of an "L"-shaped welding positioning plug; Appendix Figure 3 Assembly diagram: Appendix Figure 4 Schematic diagram of austenitic penetration fillet weld In the figure, 1. Web plate; 2. Steel structure panel; 3. Bevel; 4. Fitting end; 5. Gap end; 6. Plug positioning weld; 7. Bevel assembly gap; 8. Bevel face weld; 9. Backside weld. Detailed Implementation

[0012] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of 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, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0013] In this invention, all embodiments, implementation methods, and features can be combined with each other without contradiction or conflict. In this invention, conventional equipment, devices, and components can be commercially available or self-made according to the disclosure of this invention. In this invention, to highlight the key points, some conventional operations and equipment, devices, and components are omitted or only briefly described.

[0014] See the attached instruction manual. Figure 1-4 A method for welding austenitic high-strength steel fillet welds without root removal includes the following steps: Step 1: Analyze the steel structure panel 2 that needs to be welded, and test the mechanical properties and chemical composition of the constituent materials of the steel structure panel 2.

[0015] Step 2: Based on the thickness, specifications, and dimensions of the steel structure panel 2 to be welded, process the web plate 1 that requires corner welding with a single-sided V-shaped bevel 3. The bevel 3 is processed according to the welding space and the accessibility of single-sided welding.

[0016] Specifically, in step 2, refer to the appendix of the instruction manual. Figure 1 The V-groove 3 is processed according to the plate thickness and size. The angle of the groove 3 is processed according to the plate thickness and size. Taking the welding of the full penetration fillet weld as an example, the angle of the groove 3 is about 50°. The welding assembly gap between the groove and the panel 2 is about 5mm. The V-groove 3 is processed according to the welding space and the accessibility of single-sided welding.

[0017] Step 3: Use an "L"-shaped welding positioning block to position the bevel of the web plate 1. The block consists of a mating end 4 and a gap end 5 that are perpendicular to each other. The gap end 5 fits with the bevel assembly gap 7, and the mating end 4 fits the web plate 1. To ensure the uniformity of the bevel assembly gap 7 and to ensure that the block can be removed in time, the gap end 5 of the "L"-shaped positioning block adopts a slope structure. The slope thickness should include the size of the bevel assembly gap 7. The tensile strength of the material used should be lower than that of the base material being welded. Due to the presence of the "L"-shaped welding positioning block in the bevel gap, the welding shrinkage is ensured to be uniform, thereby ensuring that the bevel assembly gap 7 is uniform and can be removed in time after positioning.

[0018] Specifically, in step 3, refer to the appendix of the instruction manual. Figure 2 The "L"-shaped welding positioning plug is made of low-alloy steel and consists of a mating end 4 and a gap end 5 that are perpendicular to each other. The gap end 5, away from the mating end 4, is machined with a bevel to form a slope structure. (See attached instruction manual.) Figure 3 The "L"-shaped positioning plug is inserted into the bevel assembly gap 7. When the mating end 4 is in contact with the web plate 1, the "L"-shaped positioning plug is positioned. At this time, the web plate 1 and the steel structure panel 2 are perpendicular to each other. The contact position between the welding mating end 4 and the web plate 1 and the steel structure panel 2 forms a plug positioning weld 6, preventing the web plate 1 and the steel structure panel 2 from shaking, and awaiting the next welding operation. The bevel of the gap end 5 should be of uniform thickness to ensure the uniformity of the welding assembly gap, and can be removed in time after positioning.

[0019] Step 4: Select matching welding materials according to the composition of steel structure panel 2 and web 1, and conduct welding tests to preliminarily determine welding requirements such as welding materials, current, voltage, speed, and specifications. Continue welding tests until the relevant parameters meet the requirements of the weld after welding, and then use this as the welding method for penetration fillet weld.

[0020] Specifically, in step 4, the welding material is austenitic welding material. The root pass welding uses shielded metal arc welding (SMAW) with a Φ4.0mm electrode diameter, a welding current of 120–150A, and an arc voltage of 24–28V. A welding test is conducted. First, the contact surface between the web 1 and the gap end 5 is welded to form a bevel weld 8. Then, the locating plug 6 is pried open, the "L"-shaped welding locating plug is removed, and the bevel surface of the web 1 is welded again, gradually filling and penetrating to form a reverse weld 9. After the weld cools, the welding quality is inspected, and the welding test is completed. After passing the test, this material is used to complete the unrooted welding of high-strength steel austenitic full penetration fillet welds, and the test parameters are used as welding requirements, serving as the welding method for unrooted full penetration fillet welds.

[0021] The steel structure panel 2 and web 1 described in this invention are both austenitic high-strength steel. The method described in this invention is particularly suitable for welding fillet welds made of austenitic high-strength steel without root removal.

[0022] Applications of this invention: Taking the welding of circular and square supports and embedded parts in the rigid fixing of a steel structure test platform as an example, due to strength requirements, the weld is required to be a full penetration fillet weld. Furthermore, the welding process must ensure uniform welding deformation to guarantee the stability and levelness of the platform. Both the supports and embedded parts are made of thick, low-alloy high-strength steel. The internal space of the circular and square supports is limited, and the location of the weld has insufficient space for carbon arc gouging, making it impossible to carry out carbon arc gouging. If preheating and post-heating are uneven, the platform's levelness will change unevenly due to the thermal expansion and contraction characteristics of the materials. To solve the above problems and welding construction risks, the welding method described in this invention is used. First, the bevel of the support welding area is processed into a single V-shaped bevel. During assembly, an "L"-shaped welding positioning block is used to ensure the uniformity of the gap. Austenitic stainless steel welding material is used to avoid preheating and post-heating, reducing deformation caused by heating. Then, qualified welding rods are used for root removal welding to complete the welding construction. The method described in this invention avoids the need for carbon arc gouging during the welding process, which can damage the weld or the face plate and web. The quality and levelness of the structural weld meet the requirements.

[0023] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for welding high-strength steel austenitic penetration fillet welds without root removal, characterized in that: Including an "L"-shaped welding positioning plug, the "L"-shaped welding positioning plug is composed of a mating end (4) and a gap end (5) perpendicular to each other, and the gap end (5) is far away from the mating end (4) to form a slope structure. The "L"-shaped welding positioning plug is used to perform rootless welding of austenitic high-strength steel penetration fillet welds. Includes the following steps: Step 1: Analyze the steel structure panel (2) to be welded, and test the mechanical properties and chemical composition of the constituent materials of the steel structure panel (2); Step 2: According to the specifications of the steel structure panel (2) to be welded, the web plate (1) that needs to be corner welded is processed with a single-sided V-shaped bevel (3). The bevel (3) is processed according to the welding space and the accessibility of single-sided welding. Step 3: Use an "L"-shaped welding positioning plug to position the bevel of the web plate (1). The gap end (5) matches the bevel assembly gap (7), and the fitting end (4) fits the web plate (1). In order to ensure the uniformity of the bevel assembly gap (7) and to ensure that the "L"-shaped welding positioning plug can be removed in time, the thickness of the slope structure of the gap end (5) in the "L"-shaped welding positioning plug includes the size of the bevel assembly gap (7). The tensile strength of the material of the "L"-shaped welding positioning plug is lower than that of the base material to be welded. In step 3, the material of the "L"-shaped welding positioning plug is low alloy steel. When the fitting end (4) is fitted with the web plate (1), the positioning of the "L"-shaped welding positioning plug is completed. The web plate (1) and the steel structure panel (2) are perpendicular to each other. The welding fitting end (4) forms a plug positioning weld (6) at the contact position with the web plate (1) and the steel structure panel (2), so that the web plate (1) and the steel structure panel (2) do not shake, and wait for the next welding operation. Step 4: Select matching welding materials according to the composition of the steel structure panel (2) and web (1), preliminarily determine the welding materials, current, voltage and speed requirements, conduct welding tests until the relevant parameters meet the requirements of the weld after welding, and then use it as the welding method for penetration fillet weld.

2. The method for welding high-strength steel austenitic penetration fillet welds without root pass as described in claim 1, characterized in that: In step 4, the welding material is austenitic welding material. The root pass welding is performed by shielded metal arc welding with a welding rod diameter of Φ4.0mm, a welding current of 120-150A, and an arc voltage of 24-28V. The welding test is carried out. First, the contact surface between the web (1) and the gap end (5) is welded to form a bevel weld (8). Then, the plug positioning weld (6) is pried open, the "L"-shaped welding positioning plug is removed, and the bevel surface of the web (1) is welded. The filler is gradually filled and welded through to form a reverse weld (9). After the weld cools, the welding quality is checked and the welding test is completed.

Images