CN116117283A

CN116117283A - Bridge steel thick plate narrow-gap butt joint form and welding method

Info

Publication number: CN116117283A
Application number: CN202211531230.1A
Authority: CN
Inventors: 黄会强; 吴小兵; 王晓辉; 路玉荣; 徐龙强
Original assignee: China Railway Baoqiao Zhoushan Co ltd; China Railway Baoji Bridge Group Co Ltd
Current assignee: China Railway Baoqiao Zhoushan Co ltd; China Railway Baoji Bridge Group Co Ltd
Priority date: 2022-12-02
Filing date: 2022-12-02
Publication date: 2023-05-16

Abstract

The invention relates to a bridge steel thick plate narrow-gap butt joint form and a welding method, which avoid the turning welding and gouging of oversized parts through single-sided welding and double-sided forming; the butt joint groove is in a V-shaped narrow gap groove, the groove angle is 8-12 degrees, the groove gap is 8-10mm, the bottom of the groove adopts a butt joint structure of ceramic gaskets and steel bars, the area of the groove is reduced by two thirds, the metal filling amount of a welding seam is reduced, the production cost is reduced, and the welding efficiency is improved; the wire feeding mechanism suitable for narrow-gap swing welding is designed, a narrow-gap submerged arc welding method of a swing electrode is adopted, two bevel edges are better in fusion, and the joint performance is safe and reliable. The bridge steel thick plate narrow-gap butt joint form and the welding method provided by the invention have the advantages of high quality guarantee efficiency, reduced welding quantity and welding material consumption, avoidance of secondary turning and gouging, improvement of welding efficiency, effective control of welding quality and great saving of manufacturing cost.

Description

Bridge steel thick plate narrow-gap butt joint form and welding method

Technical Field

The invention relates to a bridge steel thick plate narrow-gap butt joint form and a welding method, which can be used for guaranteeing quality and reducing welding quantity and welding material consumption, avoiding secondary turning and gouging, improving welding efficiency, effectively controlling welding quality and greatly saving manufacturing cost, and belongs to the field of steel bridge manufacturing.

Background

The domestic nest-horse road-rail dual-purpose Yangtze river bridge river-crossing section adopts a multi-channel combined construction scheme of nest-horse railway, reserved railway and city expressway. The main truss transversely adopts a three-main truss structure and an N-shaped truss, three high-strength bridge structural steels Q370qE, Q420qE and Q500qE are adopted, the thicknesses of the main truss gusset plates and the web plates reach 48mm, and the gusset plates and the web plates adopt a penetration butt joint mode. The traditional welding mode is that an asymmetric X-shaped groove is formed on a butt joint, solid welding wire bottoming (GMAW) and submerged arc filling cover Surface (SAW) are adopted, and air gouging and back gouging are carried out after a plate is turned over, and then automatic submerged arc welding filling cover surface welding is carried out. However, the welding by adopting the composite welding method has the following defects: (1) The thick plate is provided with an X-shaped groove or a U-shaped groove, the groove is realized by machining, the filling quantity of welding seams of the groove is large, the welding deformation is difficult to control, and the welding material and labor cost are high; (2) The large amount of filling metal causes uneven weld joint structure and unstable joint mechanical property; (3) The back surface of the welding line needs gouging and back chipping, which is easy to generate defects such as slag inclusion; (4) The node plates and the web plates are large in structural size, single elements are difficult to turn over, manufacturing cost is high, and simultaneously, the oversized parts turn over to cause structural deformation.

Disclosure of Invention

The design purpose is as follows: the defects in the background art are avoided, and the bridge steel thick plate narrow-gap butt joint type and the welding method are designed, so that quality guarantee efficiency is improved, welding amount and welding material consumption are reduced, secondary turning and gouging are avoided, welding efficiency is improved, welding quality is effectively controlled, and manufacturing cost is greatly saved.

The design scheme is as follows: in order to achieve the above design objective. The invention provides a bridge steel thick plate narrow-gap butt joint form and a welding method, which firstly avoid the turning welding and gouging of oversized parts through single-side welding and double-side forming, improve the welding efficiency and effectively control the welding quality; secondly, the butt joint groove is in a V-shaped narrow gap groove form, the groove can be realized through flame cutting, machining is not needed, the area of the groove is reduced by two thirds, the metal filling amount of a welding line is reduced, the production cost is reduced, an efficient manufacturing technical scheme is provided for thick plate welding, and the welding efficiency is improved; thirdly, a narrow-gap submerged arc welding method of the swinging electrode is adopted, the fusion of two bevel edges is good, and the joint performance is safe and reliable; the butt joint groove is in a V-shaped narrow gap groove, the groove angle is 8-12 degrees, the groove gap is 8-10mm, the bottom of the groove adopts a butt joint structure of a ceramic liner and a steel bar, the area of the groove is reduced by two thirds, the metal filling amount of a welding line is reduced, the production cost is reduced, and the welding efficiency is improved; fifthly, a wire feeding mechanism suitable for narrow-gap swing welding is designed, (a bending device is driven leftwards and rightwards along the vertical direction of a welding line in the wire feeding process of a welding wire, so that the welding wire is in a wavy bending state, the end head of the welding wire is close to the edge of a base metal during welding, and good fusion of the edges of grooves is ensured), a narrow-gap submerged arc welding method of a swing electrode is adopted, fusion of two edges of the grooves is good, and the joint performance is safe and reliable; the bridge steel thick plate narrow-gap butt joint type and the welding method designed by the invention have the advantages of high quality guarantee efficiency, reduced welding quantity and welding material consumption, avoidance of secondary turning and gouging, improved welding efficiency, effective control of welding quality and great saving of manufacturing cost.

The technical scheme is as follows: the bridge steel thick plate narrow gap butt joint structure is formed by splicing plates, steel bars and ceramic gaskets, the joint welding adopts narrow gap gun head submerged arc automatic welding of a swinging electrode, namely: (1) Adopting numerical control flame cutting equipment to respectively process a jointed board and a jointed board groove, wherein the angle of the groove on one side is 4-6 degrees, the thickness range of the jointed board and the jointed board is 30-50mm, a 1:8 transition slope is formed on the thick board when the jointed boards are butted in unequal thickness, the steel bar is flame-processed to form a steel bar plate, the thickness of the steel bar plate is 6-8mm, the material is the same as that of the jointed board, and the type TG20271406 ceramic liner and the welding wire diameter of the submerged arc welding wire CJQ-1 and the SJ105q welding flux are selected for standby; (2) The edges of the grooves of the jointed boards and the steel bars are polished and derusted and then are assembled into an inverted trapezoid structure, the assembly clearance is 8-10mm, the assembled joint groove area is preheated, and the preheating temperature is 100-150 ℃; (3) A submerged arc welding gun with narrow gap swing welding is adopted, the diameter of the gun head of the welding gun is 8mm, a welding wire is bent by a bending forming wheel to form a wave shape, and the electrode swing is realized in the wire feeding process; (4) And welding the assembled joints by adopting narrow-gap submerged-arc automatic welding of the swinging electrode.

Compared with the background technology, the invention firstly avoids the turn-over welding and air gouging of oversized pieces through single-sided welding and double-sided forming; the butt joint groove is in a V-shaped narrow gap groove, the angle of the groove is 8-12 degrees after assembly, the gap of the groove is 8-10mm, the bottom of the groove adopts a butt joint structure of a ceramic liner and a steel bar, the filling amount of weld metal is reduced by 60% compared with the traditional process, the production cost is reduced, and the welding efficiency is improved; thirdly, steel bars are added at the bottom of the butt joint groove to ensure that the ceramic liner is not burnt through, the reverse surface is well formed, and the ceramic liner can be melted into a welding line as a part of filling metal after electric arc melting, so that the welding efficiency is improved; and fourthly, a wire feeding mechanism suitable for narrow-gap swing welding is designed, a narrow-gap submerged arc welding method of a swing electrode is adopted, two bevel edges are better in fusion, and the joint performance is safe and reliable.

Drawings

FIG. 1 is a schematic illustration of an equal thickness narrow gap splice joint.

Fig. 2 is a schematic view of a splice joint with unequal thickness and narrow gaps.

FIG. 3 is a schematic view of the cutting angle of the grooves of the jointed boards.

Fig. 4 is a schematic view of cutting angles of grooves of jointed boards and cutting transition slopes.

FIG. 5 is a schematic view of a narrow gap swing electrode submerged arc welding gun.

FIG. 6 is a schematic diagram of example 1.

FIG. 7 is a schematic diagram of example 2.

Fig. 8 is a macroscopic metallographic photograph.

Detailed Description

Example 1: reference is made to fig. 1-5. A bridge steel thick plate narrow-gap butt joint form and a welding method thereof are provided: as shown in fig. 1 and 2, the joint structure is formed by splicing a jointed board 1, a jointed board 2, a steel bar 3 and a ceramic liner 4, and the joint welding adopts a narrow-gap submerged arc automatic welding method (a narrow-gap gun head 5) of a swinging electrode. The splicing groove formed by splicing the

jointed boards

1, 2, the steel bars 3 and the ceramic liner 4 can be realized by flame cutting without mechanical processing. The groove processing and splicing steps are as follows:

(1) And (3) adopting numerical control flame cutting equipment to respectively process grooves of the jointed board 1 and the jointed board 2, wherein the angle of the groove on one side is 4-6 degrees (as shown in figure 3), the thickness range of the jointed board 1 and the jointed board 2 is 30-50mm, a 1:8 transition slope is formed in the thick board when the jointed boards are in unequal thickness butt joint (as shown in figure 4), the steel strip 3 is subjected to flame processing, the thickness of the steel strip 3 is 6-8mm, the material is the same as that of the jointed board, and the type TG20271406 ceramic liner and the welding wire diameter are selected for standby use, namely submerged arc welding wires CJQ-1 and SJ105q welding flux.

(2) The edges of the grooves of the jointed boards and the steel bars are polished and derusted to be assembled into the structure form of fig. 1 and 2, the assembly clearance is 8-10mm, the groove area of the assembled joint is preheated, and the preheating temperature is 100-150 ℃. The steel bar 3 can ensure that the ceramic liner 4 is not burnt through, ensure that the reverse surface is well formed, and can also be used as a part of filling metal after being melted by an electric arc to be melted into a welding line, thereby improving the welding efficiency.

The submerged arc welding gun 5 (shown in figure 5) suitable for narrow-gap swing welding, which is designed by the invention, has the gun head diameter of 8mm, and the welding wire is bent by the bending forming wheel to form a wave shape, so that the electrode swing is realized in the wire feeding process.

The assembled joints are welded by adopting narrow-gap submerged arc automatic welding of swinging electrodes, the welding machine has the functions of electrode swinging and infrared seam tracking, the welding gun is a narrow-gap welding gun 5, the diameter of the welding wire is 4.0mm, the welding current is 500-600A, the welding voltage is 30-34V, the welding speed is 22-26m/h, the electrode swinging frequency is 1 time per second, the welding flux SJ105q is dried for 2 hours at 350-400 ℃, and the layer temperature is controlled at 120-150 ℃. The welded joint is covered with heat-insulating cotton for slow cooling, so that cracks are prevented from being generated due to rapid cooling after welding. After 48 hours of welding, the joint is subjected to 100% UT detection, and the detection grade is BI grade.

Example 1: step 1: and (3) selecting a steel plate with the thickness of 50mm and the material of Q420qE, and cutting a jointed plate groove by flame. The steel bar is formed by cutting a steel plate with the diameter of 8mm and Q420qE by plasma, a welding material is a submerged arc welding wire with the diameter of CJQ-1 and the diameter of 4mm which are matched with a base material, the welding flux is matched with SJ105Q, and the ceramic liner model is TG20271406.

Step 2: the groove-processed jointed

boards

1 and 2 are assembled according to fig. 6 after polishing and rust removal.

Step 3: and (3) the welding equipment, the wire feeding mechanism and the welding material are well turned, welding parameters are set, the welding current is 600A, the welding voltage is 30V, the welding speed is 25m/h, and the electrode swing frequency is 1 time per second. Preheating the groove area of the spliced joint, wherein the preheating temperature is 100 ℃.

Step 4: the narrow gap swing electrode submerged arc welding groove is adopted, the interlayer temperature is controlled at 120-150 ℃ in the welding process, the fusion condition of each layer of welding bead is observed in real time, clean slag is required to be removed before the subsequent welding seam welding, and polishing and splashing are required.

Step 5: in order to ensure the mechanical property of the welding seam, heat preservation cotton is covered on the welding seam area after welding for heat preservation and slow cooling. And (5) cooling the test board for 48 hours, and performing ultrasonic flaw detection, wherein the flaw detection result is 100% qualified.

Step 6: and (3) carrying out mechanical property test and macroscopic metallurgical observation on the welding test plate, wherein the mechanical property meets the index requirement (the result is shown in table 1), and the macroscopic metallographic photograph shows that the welding seam has good internal fusion and no defects such as slag inclusion.

Example 2: step 1: and (3) selecting a steel plate with the thickness of 48mm and the material of Q370qE, and cutting the jointed plate groove by flame. The steel bar is formed by plasma cutting of a steel plate with the diameter of 8mm and Q370qE, a welding material is a submerged arc welding wire with the diameter of CJQ-1 and the diameter of 4mm which are matched with a base material, the welding flux is matched with SJ105Q, and the ceramic liner model is TG20271406.

Step 2: the groove-processed jointed

boards

1 and 2 are assembled according to fig. 7 after polishing and rust removal.

Step 3: and (3) the welding equipment, the wire feeding mechanism and the welding material are well turned, welding parameters are set, the welding current is 550A, the welding voltage is 30V, the welding speed is 26m/h, and the electrode swing frequency is 1 time per second. Preheating the groove area of the spliced joint, wherein the preheating temperature is 150 ℃.

TABLE 1 specified values of mechanical properties of welded joints

It should be understood that: although the above embodiments describe the design concept of the present invention in more detail, these descriptions are merely descriptions of the design concept of the present invention, and not limitations on the design concept of the present invention, and any combination, addition or modification not exceeding the design concept of the present invention falls within the scope of the present invention.

Claims

1. A bridge steel thick plate narrow gap butt joint form and a welding method are characterized in that: the butt joint structural style is assembled by makeup (1), makeup (2), billet (3), ceramic liner (4), and the joint welding adopts narrow clearance rifle head (5) submerged arc automatic weld of swing electrode, namely:

the method comprises the steps of (1) adopting numerical control flame cutting equipment to respectively process grooves of a jointed board (1) and a jointed board (2), wherein the single-side groove angle is 4-6 degrees, the thickness range of the jointed board (1) and the jointed board (2) is 30-50mm, a 1:8 transition slope is formed in a thick plate when the jointed boards are in unequal thickness butt joint, a steel strip (3) is subjected to flame processing, the thickness of the steel strip (3) is 6-8mm, the material is the same as that of the jointed board, and a type TG20271406 ceramic liner and submerged arc welding wires CJQ-1 and SJ105q welding flux with the diameter of 4.0mm are selected for standby;

(2) The edges of the grooves of the jointed boards and the steel bars are polished and derusted and then are assembled into an inverted trapezoid structure, the assembly clearance is 8-10mm, the assembled joint groove area is preheated, and the preheating temperature is 100-150 ℃;

(3) A submerged arc welding gun (5) with narrow gap swing welding is adopted, the diameter of the gun head of the welding gun is 8mm, a welding wire is bent by a bending forming wheel to form a wave shape, and the electrode swing is realized in the wire feeding process;

(4) And welding the assembled joints by adopting narrow-gap submerged-arc automatic welding of the swinging electrode.

2. The bridge steel slab narrow gap butt joint form and welding method according to claim 1, characterized in that: the splicing groove can be realized through flame cutting, and mechanical processing is not needed.

3. The bridge steel slab narrow gap butt joint form and welding method according to claim 1, characterized in that: the submerged arc welding gun (5) has the functions of electrode swing and infrared seam tracking, and the welding gun is a narrow-gap welding gun (5).

4. The bridge steel slab narrow gap butt joint form and welding method according to claim 1, characterized in that: the welding current is 500-600A, the welding voltage is 30-34V, the welding speed is 22-26m/h, the electrode swinging frequency is 1 time per second, the welding flux SJ105q is dried for 2h at 350-400 ℃, and the layer temperature is controlled at 120-150 ℃.

5. The bridge steel slab narrow gap butt joint form and welding method according to claim 1, characterized in that: the steel bar (3) can ensure that the ceramic liner (4) is not burnt through, ensure that the reverse surface is well formed, or be used as a part of filling metal to be melted into a welding line after being melted by an electric arc, thereby improving the welding efficiency.

6. The bridge steel slab narrow gap butt joint form and welding method according to claim 1, characterized in that: the welded joint is covered with heat-insulating cotton for slow cooling, so that cracks are prevented from being generated due to rapid cooling after welding.

7. The bridge steel slab narrow gap butt joint form and welding method according to claim 1, characterized in that: after 48 hours of welding, the joint is subjected to 100% UT detection, and the detection grade is BI grade.