CN110695618A - H-shaped steel welding process - Google Patents

Abstract

The invention discloses an H-shaped steel welding process, which has the technical scheme main points that: the method comprises the steps of firstly, blanking flange plates and webs in a classified mode; step two, pre-assembling H-shaped steel; step three, assembling H-shaped steel; step four, checking the assembly precision; fifthly, welding H-shaped steel; step six, weld joint UT detection, appearance size inspection and weld joint appearance inspection; seventhly, correcting the H-shaped steel; drilling holes at two ends of the H-shaped steel; step nine, derusting the steel structure; step ten, checking finished products; and step eleven, loading and sending. The invention solves the technical problem of how to improve the processing precision of the H-shaped steel.

Description

H-shaped steel welding process

Technical Field

The invention relates to a steel welding process, in particular to an H-shaped steel welding process.

Background

The H-shaped steel is an economic section efficient section with more optimized section area distribution and more reasonable strength-to-weight ratio, and is named because the section is the same as the English letter H. Because all parts of the H-shaped steel are arranged at right angles, the H-shaped steel has the advantages of strong bending resistance, simple construction, cost saving, light structure weight and the like in all directions and is widely applied.

In the prior art, a patent document with application publication number CN102059524A is referred to, which relates to a manufacturing process of a solid welded H-shaped steel plate, mainly comprising the following steps: 1) blanking jointed boards; 2) i-shaped form assembly; 3) automatic submerged arc welding; 4) correcting; 5) hole making; 6) sawing off; 7) locking the opening; 8) cleaning and grinding; 9) and (6) end face processing. The method has the advantages of simple steps, easy operation, capability of saving a large amount of human resources, stable quality of the processed H-shaped steel plate, good end surface smoothness, good bearing performance and steel consumption saving.

The processing of H shaped steel only adopts comparatively simple processing technology in this comparison file, and to the higher flange board of required precision and web unloading, this comparison file handles comparatively crudely, can not reach the high accuracy requirement, so how to guarantee that H shaped steel machining precision is higher is a problem that needs to solve.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide an H-shaped steel welding process, which comprises the steps of strictly inspecting raw materials entering a factory, pre-leveling after inspection, inspecting each blanking of a flange plate and a web plate, blanking two flange plates once, splicing together and welding, pre-assembling H-shaped steel to correct manufacturing errors, assembling, welding, correcting and coating strictly and normatively after hole turning, so that the machined H-shaped steel has better machining precision.

In order to achieve the purpose, the invention provides the following technical scheme: the welding process of the H-shaped steel comprises the steps of firstly, blanking and cutting flange plates and webs in a classified mode; step two, H-shaped steel is pre-assembled, the site is prepared, the construction site must be a tamping site, the pre-assembly is carried out on a solid and stable pre-assembly platform or a jig frame, and the levelness of a supporting point is as follows: the area is less than or equal to 300-1000m2, and the allowable deviation is less than or equal to 2 mm; the area is less than or equal to 1000-1500m2, and the allowable deviation is less than or equal to 3 mm; various conditions in the pre-assembly are controlled according to the size of a construction drawing, the central lines of all rod pieces are intersected at the center of a node and are completely in a free state, external force is not allowed to forcibly fix the rod pieces, and no matter a column, a beam and a support are supported, no less than two supporting points are needed for a single rod piece; the center line of the control reference of the pre-assembled steel plate is clearly marked and is consistent with the platform reference line and the ground reference line; in the whole process of pre-assembling on the jig frame, the steel plate can not be directly corrected and cut on the jig frame by flame or mechanical means or the like, or ballast, impact and hammer by using a heavy object; when the high-strength bolt connecting piece is preassembled, impact positioning and temporary bolt fastening can be used; the trial assembly of the bolts in a group of holes is not less than 30 percent of the bolt holes and is not less than 2; 1/3 for punch pins less than temporary bolts; after pre-assembling, using a hole tester for inspection, wherein when the hole tester with the diameter smaller than the nominal diameter of the hole by 0.1mm is used for inspection, the passing rate of each group of holes is 85%, and the hole tester needs to vertically and freely penetrate through; assembling the H-shaped steel, and assembling the welded H-shaped steel on an H-shaped steel automatic assembling machine of an H-shaped steel production line; the web and the flange plate are subjected to local unevenness inspection before assembly; before assembling the I-shaped structure, oil rust and other dirt in four main welding seam areas are required to be removed, the derusting width of a web plate is generally 20-30mm, and the derusting width of a cover plate is not less than the thickness of the web plate plus 50 mm; assembling an H-shaped steel on an automatic H-shaped steel assembling machine; checking the assembly precision, wherein the position of a machine head of the assembling machine is adjusted during assembly, and measuring the assembly deviation of the H-shaped steel while assembling; welding H-shaped steel, wherein four main seams of the H-shaped steel are welded by adopting submerged arc welding on an H-shaped steel production line; welding the lower left corner, welding the upper right corner, actually welding the lower right corner, and finally welding the upper left corner; step six, weld joint UT detection, appearance size inspection and weld joint appearance inspection; seventhly, H-shaped steel is corrected, deformation correction is carried out on the H-shaped steel through a flange straightening machine, the end face is milled after correction, the end face is guaranteed to be flat, appearance size inspection is carried out after the end face is milled, and whether deformation occurs in the H-shaped steel is checked; drilling holes at two ends of the H-shaped steel, and allowing punching when the quality, thickness and aperture of certain materials are proved and brittleness is not caused after punching; when drilling, checking the position of the web plate, wherein the offset of the scribing is less than or equal to 1mm, and selecting different drill bit forms according to different partition plate thicknesses; the original 200mm datum line is used as the standard for drilling; all common structural steel with the thickness below 5mm allows punching, and the secondary structural steel with the thickness less than 12mm allows punching; on the punched hole, welding (groove shape) cannot be carried out subsequently, and welding construction can be carried out unless the material still retains considerable toughness after punching is proved; generally, when the hole to be punched is drilled to be larger, the punched hole is required to be smaller than the specified diameter by 3 mm; step nine, derusting a steel structure: the rust removal grade needs to meet the requirements of the design of a drawing; various priming paints, intermediate paints and finishing paints have good priming compatibility, including performance matching, hardware matching, drying humidity matching and the like; after the rust removal is qualified, coating rust-proof primer twice, coating finish once on site, and coating finish once on the local part of the damaged part of the paint surface after the installation is finished, wherein the total thickness of a paint film is not less than 125 mu m; the color of the finish paint is required to meet the requirements of drawings; the humidity of the coating construction environment is preferably constructed under the condition that the relative humidity is not more than 85 percent; when coating, the environment temperature is preferably between 5 and 38 ℃; selecting the optimal time for coating, namely, after sunrise for 3 hours, the time is within 3 hours after sunrise (indoor operation is not limited); in the following cases, construction is generally impossible, and protective measures are needed if construction is needed: construction outdoors is prohibited in environments with rain, fog, snow and large dust; the surface of the steel plate should not be dewed during coating, and should be protected from rain within 4 hours after coating; the coating can be polluted by dust, oil stain, salt and corrosive media; when the light of the construction operation environment is seriously insufficient; under the conditions of safety measures and fireproof and explosion-proof tools and instruments; the painting interval time has great influence on the quality of the coating, and the interval time is properly controlled, so that the adhesion between the coatings and the comprehensive protection performance of the coatings can be enhanced; shielding before coating: shielding and protecting parts which may affect the paint coating prohibition during construction before construction; the part with larger area can be pasted with paper and firmly pasted with adhesive tape, and the part with smaller area can be completely pasted with adhesive tape; coating personnel engaged in the project must have the working experience of engaging in similar coating projects for more than half a year and obtain the coating on duty certificate; step ten, finished product inspection, namely performing partial selective inspection on the finished product, labeling according to a construction drawing after the selective inspection is qualified, packaging the finished product, paying attention to protection, coating a protective film on the edge-processed groove, and paying attention to no collision; and step eleven, loading and sending.

By adopting the technical scheme, when H-shaped steel is processed, the flange plates and the web plates are respectively blanked firstly, blanking is completed and cut into required size, discharging is pre-assembled firstly, a construction site is carried out on a tamped site and is carried out on a solid and stable pre-assembly platform or a jig frame, and the levelness of the fulcrum is strictly controlled. At least twelve supporting points are adopted for supporting, and pre-assembly is carried out for correcting manufacturing errors.

The H-shaped steel is assembled, four main welding seam areas are decontaminated before the H-shaped steel is assembled, the welding seam areas are clean and free of oil rust before welding, welding is carried out after assembly precision inspection is carried out, welding is carried out according to the sequence of left lower, right upper, right lower and left upper, the H-shaped steel is welded through the sequence, welding seam deviation after welding is smaller, the central offset of the upper flange plate and the lower flange plate is smaller, UT inspection and appearance size inspection are carried out through an ultrasonic flaw detector, machining precision is guaranteed to meet the standard, holes of different types are drilled through different drilling methods, rust removal painting maintenance is carried out on the left rear side, loading and sending are carried out after the rust removal painting maintenance is carried out on the left rear side, and machining precision is higher after the manufacturing of the H-shaped steel is shut down layer by layer.

The invention is further configured to: the method also comprises a raw material factory inspection link, wherein the factory inspection is carried out before blanking of the flange plate and the web plate, and the inspection process comprises material quality certification and inspection of material identification and material allowable deviation; the materials can be put into use after being inspected to be qualified;

when the surface of the steel has defects such as rust, pockmark or scratch, the depth of the steel is not more than the negative deviation value 1/2 of the thickness of the steel, otherwise, the steel cannot be used; except that the factory quality certificate of the production factory must be provided, and should be under the contract requirement and the relevant existing standard in the first prescription, prison's witness, carry on witness sampling, sample sending, inspection and acceptance, make the inspection record; and providing inspection reports to the first party and the proctoring; the use of welding rods with falling flux coatings or rusty core wires, welding fluxes which are moistened and caked or are melted and rusty welding wires is strictly forbidden; the surface of the stud used for stud welding must not affect the defects of cracks, streaks, dents, burrs and the like used; the welding materials should be managed in a centralized way, a special warehouse is established, and the warehouse needs to be dried and well ventilated; the coating meets the design requirements and is stored in a special warehouse, and the coating which is overdue, deteriorated and failed by agglomeration cannot be used.

By adopting the technical scheme, the raw materials are subjected to factory inspection according to strict standards, the defects of the raw materials such as welding wire studs and the like which influence processing are avoided, and the raw materials are stored under the conditions of drying and good ventilation through a special warehouse.

The invention is further configured to: the steel plate is preliminarily leveled after being inspected to be qualified when entering a factory, and raw materials after being inspected to be qualified are placed into a steel plate leveling machine to be leveled, so that the cutting quality and the blanking precision are prevented from being influenced by the unevenness of the steel plate; after the steel is leveled, lofting and material marking are firstly carried out, and 1:1, lofting, wherein the actual size of each steel plate is determined according to a design drawing during lofting; manual lofting is carried out on a flat lofting platform, and all steel plates for lofting are required to be released in a proportion of 1: 1; when materials are numbered, the welding seams of the H-shaped wing plates and the web plates cannot be arranged on the same cross section, and are staggered with each other by more than 200mm and staggered with the partition plates by more than 200 mm; the material receiving mode adopts a large plate material receiving mode as much as possible.

Through adopting above-mentioned technical scheme, carry out preliminary flattening to the raw and other materials after getting into the factory qualified earlier, guarantee that the steel sheet keeps leveling before processing, then carry out laying-out and material marking again, through with flange plate and welding seam setting in order to prevent to weld the production deviation on the cross-section of difference.

The invention is further configured to: the shrinkage (including the on-site welding shrinkage) and the required machining allowance such as cutting and end milling are reserved for lofting and material marking: milling end allowance: each side of the sheared and processed material is generally added with 3-4 mm, and each side of the sheared and processed material is added with 4-5 mm; cutting allowance: the width of the automatic gas cutting slot is 3mm, and the width of the manual gas cutting slot is 4 mm; the welding shrinkage is given by the process according to the structural characteristics of the steel plate; the material must be marked with the angle of the bevel and the direction of the blunt edge.

Through adopting above-mentioned technical scheme, through reserve the shrinkage when blowing and material marking and guarantee that the welding because high temperature makes the steel sheet warp and produce the error.

The invention is further configured to: the flange plate and the web plate are conveyed through different conveying devices again after blanking and cutting of the flange plate and the web plate are finished, the flange plate and the web plate are stopped again through a numerical control stop mechanism after reaching a specified position until the conveying mechanism conveys a second flange plate and the web plate, then the two flange plates are butted together, the two web plates are butted together, then the two flange plates and the web plate are pushed to one side of the station through a transverse pushing mechanism, and then welding of the joints of the two web plates and the two flange plates is started through a submerged arc welding machine; the double-sided butt weld which requires penetration of the butt weld is welded on one side, the weld root defect is thoroughly eliminated before the other side is welded until the metal luster of the weld joint is exposed, the welding can be carried out, but the back chipping is not allowed under the condition that the submerged arc automatic welding is adopted and the penetration of the weld joint can be ensured.

Through adopting above-mentioned technical scheme, through assembling after lengthening and welding two flange plates and web butt joint, guarantee the efficiency of processing, if the assembly is welding in the department of meeting of two H shaped steel after will lengthening earlier, need weld six welding seams in different positions department like this, welding process is complicated, adopts this kind of welding mode, only needs four welding seams of welding and can weld at the plane, and it is more simple and convenient to weld.

The invention is further configured to: adopting butt groove welding seam of a steel backing plate on the back, wherein the joint between the backing plate and a base material must be tight, and the welding metal and the backing plate should be completely fused; the method comprises the following steps that steel plates with different thicknesses are butted, one side of a thick plate is processed into a gentle transition shape, when the plate thickness difference exceeds 4mm, one side of the thick plate is processed into an inclination of 1: 2.5-1: 4, and the thickness of the butted part is equal to that of a thin plate; butt welding, except special designation, should make the welding seam surplus height minimum, the surplus height value must not exceed 3mm, and peaceful transition to the surface of parent metal; and after the welder finishes welding, cleaning the welding line, removing welding slag and welding spatter, carefully checking the appearance quality of the welding line, submitting to inspection after the welding line is qualified, and printing a steel seal of the welder near the qualified welding line.

By adopting the technical scheme, the joint parts of the two steel plates are guaranteed to be attached to each other through the back steel base plate, the plates are processed when the back steel base plate is qualified, the processing quality is guaranteed, and appearance welding quality inspection is carried out after welding of the welding line is finished so as to remove unqualified products.

The invention is further configured to: the flange plate and the web plate are continuously conveyed forwards through the conveying device after welding at the position is completed, the conveying is stopped after a certain distance is carried out, then the ultrasonic flaw detector is arranged in the middle of the conveying device to carry out UT detection, the UT detection is carried out forwards continuously after being qualified, and when the detection is unqualified, the corresponding unqualified flange plate or web plate is detached to repair the weld defects.

Through adopting above-mentioned technical scheme, whether it is qualified to carry out UT detection through the ultrasonic flaw detector to the welding seam department of flange board and web and detect the welding seam welding, and the flange board and the web that weld qualified continue the neck ring and carry, and unqualified flange board or web can be restoreed.

The invention is further configured to: after nondestructive testing is carried out on a welding line, when the overproof defect occurs, a welder cannot handle the defect freely, and needs to report that a welding technician checks the reason in time, and then a repair process measure is set and can be handled; for the cracks in the weld metal, determining the boundary range of the cracks by applying a nondestructive testing method before repairing; drilling crack-stopping holes in front of two ends of the crack, and removing the crack and welding seams or base materials of which the two ends are 50mm respectively; weld seam size, recess, undercut exceed standard, should carry on the repair welding; polishing the generated welding beading and welding line with a grinding wheel until the welding beading and the welding line are in smooth transition with the base metal; when the defects are eliminated, the gouging groove is processed into a groove with four side bevel angles larger than 10 degrees, the surface is trimmed, the gouging carburized layer is ground, and if necessary, a penetration flaw detection or magnetic particle flaw detection method is applied to determine whether the cracks are eliminated; adopting the original welding method and the process regulation to perform repair welding; when the original submerged-arc welding seam has defects, a low-hydrogen welding rod is adopted for repair welding; arc striking is carried out in the groove during repair welding, and arc pits are filled during arc extinguishing; joints among welding layers of the multi-layer welding are staggered, the length of a welding line is not less than 100mm, and when the length of the welding line exceeds 500mm, a segmented welding-back method is adopted; continuously welding the repaired part; if the welding is interrupted, post-heating and heat-preserving measures are adopted to prevent cracks from generating, and after the secondary welding is checked and confirmed to have no cracks, the repair welding can be continued by using a penetration flaw detection or magnetic particle flaw detection method; the preheating temperature of the weld joint repair is higher than that of normal welding under the same condition, and whether post-welding dehydrogenation treatment is carried out or not is determined according to the actual condition of the engineering node; the number of times of repairing the same part of the welding seam is not more than 2; repairing the unqualified parts for two times, and re-formulating a repair scheme to be approved by an engineering technical responsible person and reported to be executable after being approved by a supervision engineer; the repair welding line should be filled with the repair construction record and the nondestructive testing report before and after repair as the project acceptance and filing data.

By adopting the technical scheme, when the crack is repaired, the length of the crack is determined firstly, then repair welding is carried out after the crack-stopping hole is drilled and the gouging groove is processed, and when the length of the welding line is too long, welding is carried out by adopting a segmented welding method.

The invention is further configured to: the conveying device drives the flange plates or the web plates to continue to convey forwards and convey the flange plates or the web plates to the position of the strip steel leveling machine for leveling.

By adopting the technical scheme, the welded flange plate and the welded web plate are leveled again, so that the flange plate and the web plate are kept flat before subsequent processing, and the processing precision is prevented from being influenced by unevenness.

The invention is further configured to: the method also comprises the step of drilling the web, wherein after the step one is finished, the web is conveyed forwards continuously through the conveying device and conveyed to the position of the drilling machine for hole turning, the drilling is preferentially adopted when the web is drilled, and the punching is allowed to be adopted when the quality, thickness and aperture of certain materials are proved and brittleness is not caused after the punching; when drilling, checking the position of the web plate, wherein the offset of the scribing is less than or equal to 1mm, and selecting different drill bit forms according to different partition plate thicknesses; the original 200mm datum line is used as the standard for drilling; all common structural steel with the thickness below 5mm allows punching, and the secondary structural steel with the thickness less than 12mm allows punching; on the punched hole, welding (groove shape) cannot be carried out subsequently, and welding construction can be carried out unless the material still retains considerable toughness after punching is proved; generally, when the hole to be punched is drilled to be larger, the punched hole is required to be smaller than the specified diameter by 3 mm; after drilling, welding web studs, and carefully cleaning welded junctions before welding; the lower part of the welding arc is more than or equal to 20mm, and the upper part is more than or equal to 40 mm; the welding wire is H08Mn2SiA, and the welding flux is SH 331; when adjusting the voltage: a. arcing is 40-42V b, 54V c after adding the flux, 50-51V d after normal welding, and is reduced to 48V when the surface is about 10 mm; the non-molten nozzle electroslag welding adopts bilateral symmetry, and 6 welding machines are simultaneously welded; the stud used in the project is qualified through the identification test of the welding end before leaving the factory, and can be used; the storage of the stud is ensured to be oil-free and rust-free; the protection ceramic ring should be stored to avoid being affected with damp and oil stain, and should be baked for about 2 hours at 120 ℃ before use; the stud is welded by a special welding machine; manual welding is only used for local repair; before construction operation every day, 2 studs are firstly welded on the same material (the thickness can be changed by 25%) as the steel plate in a test mode, then a 30-degree bending test is carried out, and if the extrusion welding leg reaches 360 ℃ and no heat influence area cracks exist, formal welding can be carried out; after the stud is welded, uniform extrusion welding feet are required to be arranged within the range of 360 degrees, and other defects such as cracks and the like are avoided; 100 welded studs are used as a batch, 1% of the welded studs are spot-checked to carry out hammer knock test, the bending angle is 30 degrees, and if the extrusion welding leg has no defects such as cracks, the welded studs are considered to be qualified; in the knock test, 2 sheets are inspected again when the test fails, and if 1 sheet fails to pass, the batch is inspected completely or re-welded completely.

Through adopting above-mentioned technical scheme, drill simultaneously through 6 welding machines, let the peg deposit under the oily no rust condition in order to prevent that the peg from rustting, and drill according to corresponding precision standard, guarantee the drilling quality, and weld 2 pegs and weld, then carry out bending test to the peg, carry out welding again to the peg after bending test is qualified, the peg subdivides to carry out the hammer in batches and strikes the experiment and detect once more, thereby guarantee that the welding of peg is accurate, stable.

In summary, compared with the prior art, the invention has the following beneficial effects: according to the invention, raw materials are strictly checked in a factory, pre-leveling is carried out after checking, each blanking of the flange plate and the web plate is checked, two flange plates are blanked once and spliced together and welded, then the H-shaped steel is preassembled to correct manufacturing errors, and then assembly, welding, correction and hole rotation are carried out, and then strict and standard coating is carried out, so that the processed H-shaped steel has better processing precision. .

Drawings

FIG. 1 is a flow chart of the process in the example;

FIG. 2 is a sequence diagram of welding of H-shaped steel in the example.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings. In which like parts are designated by like reference numerals. It should be noted that the terms "front," "back," "left," "right," "upper" and "lower" used in the following description refer to directions in the drawings, and the terms "bottom" and "top," "inner" and "outer" refer to directions toward and away from, respectively, the geometric center of a particular component.

Example (b):

an H-shaped steel welding process comprises the following steps:

the method comprises the following steps that firstly, raw materials are put into a factory for inspection, and the inspection process comprises material quality certification, material identification and material allowable deviation inspection. The materials can be put into use after being qualified.

When the surface of the steel has defects such as rust, pockmark or scratch, the depth of the steel is not more than the negative deviation value 1/2 of the thickness of the steel, otherwise, the steel cannot be used.

Except for the necessary factory quality certificate of the production factory, the on-site witness sampling, sample sending, inspection and acceptance are carried out under the witness of the first party and the supervision according to the contract requirements and the related current standard, and the inspection record is made. And provide inspection reports to the first party and proctoring.

Welding rods with a coating that peels off or a core that rusts, fluxes that have wet lumps or burned, and rusty welding wires are strictly prohibited. The surface of the stud used for stud welding must not affect the defects of cracks, streaks, dents and burrs used.

The welding materials should be managed in a centralized way, a special warehouse is established, and the warehouse needs to be dried and well ventilated. The coating meets the design requirements and is stored in a special warehouse, and the coating which is overdue, deteriorated and failed by agglomeration cannot be used.

And step two, leveling the steel plate, namely leveling the qualified raw material in a steel plate leveling machine to prevent the uneven steel plate from influencing the cutting quality and the blanking precision. After the steel is leveled, lofting and material marking are firstly carried out, and 1:1 lofting, wherein the actual size of each steel plate is determined according to a design drawing during lofting. Manual lofting is performed on a flat lofting platform, and the full-scale steel plate should be released in a ratio of 1: 1.

During material marking, the welding seams of the H-shaped wing plate and the web plate cannot be arranged on the same cross section, and are staggered with each other by more than 200mm and staggered with the partition plate by more than 200 mm. The material receiving mode adopts a large plate material receiving mode as much as possible.

The shrinkage (including the on-site welding shrinkage) and the required machining allowance such as cutting and end milling are reserved for lofting and material marking:

milling end allowance: the average diameter of each side of the post-cutting processing is 3-4 mm, and the diameter of each side of the post-cutting processing is 4-5 mm.

Cutting allowance: the automatic gas cutting slot width is 3mm, and the manual gas cutting slot width is 4 mm.

The welding shrinkage is given by the process according to the structural characteristics of the steel plate.

The material must be marked with the angle of the bevel and the direction of the blunt edge.

Tolerance of material

And step three, blanking the flange plate and the web plate, respectively conveying the flange plate and the web plate into different conveying devices, ensuring that the flange plate and the steel plate stop at the positions when being conveyed to the appointed positions, and respectively pushing the flange plate and the steel plate to one side of the station through corresponding transverse pushing mechanisms after the flange plate and the steel plate stop. The blanking of the cover plate and the web plate of the H-shaped steel is programmed by a computer, the flange plate and the web plate are cut on a numerical control cutting machine after being conveyed to a set position, and the required size is cut according to the lofting of the material and the design size of the material. Quality standard of mechanical cutting

Item	Tolerance deviation (mm)
		Width and length of part	±3
Edge missing edge	1.0
		Perpendicularity of end of section steel	2.0

And fourthly, the flange plates and the web plates are in butt joint, after the flange plates and the web plates are respectively cut on different numerical control cutting machines, the flange plates and the web plates are conveyed through different conveying devices again, the flange plates and the web plates are stopped again through a numerical control material blocking mechanism after reaching a specified position until the conveying mechanism conveys the second flange plates and the web plates, then the two flange plates are in butt joint, the two web plates are in butt joint, then the two flange plates and the web plates are pushed to one side of the station through a transverse pushing mechanism, and then the joints of the two web plates and the two flange plates are welded through a submerged arc welding machine. The double-sided butt weld which requires penetration of the butt weld is welded on one side, the weld root defect is thoroughly eliminated before the other side is welded until the metal luster of the weld joint is exposed, the welding can be carried out, but the back chipping is not allowed under the condition that the submerged arc automatic welding is adopted and the penetration of the weld joint can be ensured.

And fifthly, after welding the flange plate and the web plate at the position is finished, continuously conveying the flange plate and the web plate forwards through a conveying device, stopping after conveying for a certain distance, then arranging an ultrasonic flaw detector in the middle of the conveying device for UT detection, continuously conveying the flange plate and the web plate forwards after the UT detection is qualified, and unloading the corresponding unqualified flange plate or web plate when the detection is unqualified to repair the weld defects.

After nondestructive testing, when the weld joint has the defect of standard exceeding, the welder cannot handle the weld joint without authorization, and the repair process measures are set and can be handled after the reason is found out by welding technicians is reported in time.

For the crack in the weld metal, a nondestructive testing method is applied to determine the limit range of the crack before repairing. And drilling crack-stopping holes in front of the two ends of the crack, and removing the crack and welding seams or base materials of which the two ends are 50mm respectively. The size, the recess and the undercut of the welding seam exceed the standard, and repair welding is required. And (4) polishing the generated welding beading and welding line with a grinding wheel until the welding beading and welding line are in smooth transition with the base metal.

When the defects are removed, the gouging groove is processed into a groove with four side bevel angles larger than 10 degrees, the surface is trimmed, the gouging carburized layer is ground, and if necessary, a penetration flaw detection or magnetic particle flaw detection method is applied to determine whether the cracks are removed.

Adopting the original welding method and the technological regulation to repair welding. When the original submerged arc welding seam has defects, a low-hydrogen type welding rod is adopted for repair welding. Arc striking is carried out in the groove during repair welding, and arc pits are filled during arc extinguishing; joints among welding layers of the multi-layer welding are staggered, the length of the welding line is not less than 100mm, and when the length of the welding line exceeds 500mm, a segmented welding stripping method is adopted. The repaired portion should be continuously welded. If the welding is interrupted, post-heating and heat-insulating measures are adopted to prevent cracks from generating, and after the secondary welding is checked and confirmed to be free of cracks by using a penetration inspection method or a magnetic powder inspection method, the repair welding can be continued. The preheating temperature for repairing the welding line is higher than that for normal welding under the same condition, and whether post-welding dehydrogenation treatment is carried out or not is determined according to the actual condition of the engineering node. The number of times of repairing the same part of the welding seam is not more than 2. And (4) reworking the unqualified parts after twice reworking, and reviewing and approving the parts by an engineering technical responsible person and reporting to a supervision engineer for approval and then performing. The repair welding line should be filled with the repair construction record and the nondestructive testing report before and after repair as the project acceptance and filing data.

And step six, the conveying device drives the flange plates or the web plates to continue to convey forwards, and the flange plates or the web plates are conveyed to the position of a second strip steel leveling machine to be leveled again.

And seventhly, drilling the web, continuously conveying the web forwards through the conveying device, conveying the web to the position of the drilling machine for hole turning, and preferentially drilling the web when hole making is carried out, wherein punching is allowed when the quality, thickness and hole diameter of certain materials are proved and brittleness is not caused after punching. When drilling, the position of the web plate is checked, the offset of the scribing line is less than or equal to 1mm, and different drill bit forms are selected according to different thicknesses of the partition plates. The drilling is based on the original 200mm reference line.

All common structural steels with thicknesses below 5mm allow punching, and secondary structural thicknesses less than 12mm allow punching. On the punched hole, no subsequent welding (channel formation) is necessary, and the construction can be welded unless it is demonstrated that the material remains fairly ductile after punching. Typically, when the hole to be punched is drilled larger, the punched hole must be 3mm smaller than the specified diameter. Tolerance of drilling

Item	Tolerance deviation (mm)
		Distance between two adjacent central lines	±0.5
Distance between central lines of two holes of diagonal line of rectangle and distance between centers of side holes	±1.0
		Distance between hole center and hole group center	0.5
Center distance between two hole groups	±0.5

Step eight, welding web stud bolts, and carefully cleaning welded junctions before welding. The lower part of the welding arc is more than or equal to 20mm, and the upper part is more than or equal to 40 mm.

The welding wire is H08Mn2SiA and the welding flux is SH 331.

When adjusting the voltage: a. the arcing was 40-42V b, 54V c after flux addition, 50-51V d after normal soldering, and was reduced to 48V near the surface by about 10 mm.

The non-nozzle electroslag welding adopts bilateral symmetry, and 6 welding machines are simultaneously welded.

The stud used in the project is qualified through the qualification test of the welding end before the stud leaves the factory, and can be used.

The storage of the stud is ensured to be oil-free and rust-free; the protective ceramic ring should be stored without being affected with damp and oil stain, and should be baked at 120 deg.C for about 2 hours before use.

The studs must be welded using a special welding machine. Manual welding is only used for partial repairs.

Before every day of construction operation, 2 studs are firstly welded on the same material (the thickness can be changed by 25%) as the steel plate, then a 30-degree bending test is carried out, and if the extrusion welding leg reaches 360 ℃ and no heat affected zone cracks, formal welding can be carried out.

And step nine, quality inspection of stud welding, wherein after the stud welding, uniform extrusion welding feet are required within a range of 360 degrees, and other defects such as cracks and the like are avoided.

100 welded studs are used as a batch, a hammer knock test is carried out by spot inspection of 1%, the bending angle is 30 degrees, and if the extrusion welding leg has no defects such as cracks, the welding leg is qualified.

In the knock test, 2 sheets are inspected again when the test fails, and if 1 sheet fails to pass, the batch is inspected completely or re-welded completely.

The welding inspection, the welding inspection of the steel structure should include two items of inspection and acceptance, so the welding inspection cannot be limited to only welding after the welding is finished, and the welding inspection should be performed throughout the whole welding operation, as shown in the following table:

and step ten, grooving the web, carrying out secondary scribing before end milling, marking an end milling line and an inspection line, and reserving welding shrinkage allowance for each section. And leveling the end milling platform to ensure that the perpendicularity between the end milling plane and the beam is not more than 1 mm. The end milling process is carried out on an end milling machine, and attention should be paid to the process: the end face of the structure must not have air hole dents. The temperature difference should be checked when determining the total length. When the length is in or out, the position of the clapboard is used as the standard. The feed rate is based on the plate thickness. And (5) inspecting after end milling.

The verticality and the levelness are within 0.5mm, and the checking is carried out by a level gauge if necessary.

The length L of the workpiece is less than or equal to +/-2 mm, and the right angle of the end surface is less than or equal to 1.5H/10000

Step eleven, pre-assembling the H-shaped steel in order to correct manufacturing errors, preparing a site, wherein a construction site must be a tamping site, pre-assembling is performed on a solid and stable pre-assembling platform or a jig frame, and the levelness of a fulcrum is as follows:

the area is less than or equal to 300-1000m2, and the allowable deviation is less than or equal to 2 mm;

the area is less than or equal to 1000-1500m2, and the allowable deviation is less than or equal to 3 mm.

The various conditions in the pre-assembly are controlled according to the size of a construction drawing, the central lines of all the rod pieces are intersected at the center of the node and are completely in a free state, external force is not allowed to forcibly fix the rod pieces, and the supporting points of the single rod piece are not less than two supporting points regardless of columns, beams and supports.

The center line of the control reference of the pre-assembled steel plate is clearly marked and is consistent with the platform reference line and the ground reference line.

During the whole pre-assembly process on the jig frame, the steel plate can not be directly corrected and cut on the jig frame by flame or mechanical means or the like, or can not be ballasted, collided and beaten by using a heavy object.

And step twelve, assembling the H-shaped steel, and assembling the welded H-shaped steel on an H-shaped steel automatic assembling machine in an H-shaped steel production line.

The web and flange plates are inspected for local unevenness prior to assembly.

Before assembling the I-shaped structure, oil rust and other dirt in four main welding seam areas are required to be removed, the web plate rust removal width is generally 20-30mm, and the cover plate rust removal width is not less than the thickness of the web plate plus 50 mm.

And assembling the H-shaped steel on an automatic H-shaped steel assembling machine.

And step thirteen, checking the assembly precision, adjusting the head position of the assembling machine during assembly, and measuring the assembly deviation of the H-shaped steel while assembling.

H-shaped pairing allowable deviation

Item	Tolerance deviation (mm)
		Height (h)	±1
Perpendicularity (delta)	B/100 and not more than 2.0
		Center offset (e)	±1.0
Gap (delta)	1.0

Fourteen steps of welding the H-shaped steel, and as shown in figure 2, welding four main seams of the H-shaped steel by adopting submerged arc welding on an H-shaped steel production line. The lower left corner is welded firstly during welding, then the upper right corner is welded, the lower right corner is welded actually, the upper left corner is welded finally, H-shaped steel is welded through the sequence, the welding seam deviation after welding is smaller, and the central offset of the upper flange plate and the lower flange plate is smaller.

Fifteen, weld joint UT detection and appearance size inspection, and weld joint appearance inspection: appearance inspection is carried out according to the requirements of JGJ81-2002 or GB50205-2001, 15% of all welding seams are randomly extracted for inspection, and the inspection standard is in accordance with the requirements of the following table

The quality requirement of the inside of the welding seam is in accordance with the requirement of the design of a drawing. The internal inspection must be performed after the visual inspection is passed.

The internal inspection of the weld should be performed 24 hours after welding. The magnetic powder inspection is carried out according to the current GB/T15822-1995 of magnetic powder inspection method and JB/T6061 standard of weld magnetic powder inspection method and classification of defect magnetic marks in China.

Ultrasonic detection of welding seams, wherein the welding seam appearance detection firstly needs to report a notice that the welding seam appearance inspection is qualified, then the performance of an instrument is checked, coarse flaw detection and fine flaw detection are carried out, if the detection exceeds the standard, a quality notice is filled, and if the welding seam inspection is qualified, a detection report is sent.

The ultrasonic execution Chinese standard 'Manual ultrasonic flaw detection method and flaw detection result grading' GB/T11345-1989, the number of ultrasonic detection welding lines is at least as follows:

a. primary weld seam as noted in the figure

b.100% of all beam and column splicing welding seam

c. Other welding lines are checked at least 20% according to a second-level welding line

Sixthly, H-shaped steel is corrected, deformation correction is conducted on the H-shaped steel through a flange straightening machine, the end face is milled after correction, the end face is guaranteed to be flat, appearance size inspection is conducted after the end face is milled, and whether deformation occurs in the H-shaped steel is checked.

Seventhly, drilling holes at two ends of the H-shaped steel, wherein the drilling requirements of the H-shaped steel allow punching when the quality, thickness and aperture of certain materials are proved and brittleness is not caused after punching. When drilling, the position of the web plate is checked, the offset of the scribing line is less than or equal to 1mm, and different drill bit forms are selected according to different thicknesses of the partition plates. The drilling is based on the original 200mm reference line.

All common structural steels with thicknesses below 5mm allow punching, and secondary structural thicknesses less than 12mm allow punching. On the punched hole, no subsequent welding (channel formation) is necessary, and the construction can be welded unless it is demonstrated that the material remains fairly ductile after punching. Typically, when the hole to be punched is drilled larger, the punched hole must be 3mm smaller than the specified diameter. Tolerance of drilling

Item	Tolerance deviation (mm)
		Distance between two adjacent central lines	±0.5
Distance between central lines of two holes of diagonal line of rectangle and distance between centers of side holes	±1.0
		Distance between hole center and hole group center	0.5
Center distance between two hole groups	±0.5

Eighteen, derusting a steel structure:

the rust removal grade needs to meet the requirements of the design of drawings.

The steel plate is subjected to sand blasting and rust removal before leaving a factory, the rust removal grade reaches the standard of Sa2.0-2.5 grade, and the steel plate meets the regulation of the Steel plate surface rust grade and the rust removal grade before coating (GB 8923-88).

Painting: and (3) strictly checking the surface treatment quality of the steel before painting, and judging whether the surface treatment quality reaches the rust removal quality level specified by the design, if not, removing rust again until the surface treatment quality reaches the standard.

Various priming paints, intermediate paints and finishing paints have good priming compatibility, including performance matching, hardware matching, drying humidity matching and the like.

After the rust removal is qualified, the rust-proof primer is coated twice, the finish paint is coated once again on site, the finish paint is coated once again on the part of the damaged part of the paint surface after the installation is finished, and the total thickness of the paint film is not less than 125 mu m.

The color of the finish paint is required to meet the requirements of drawings.

The humidity of the coating construction environment is generally suitable for construction under the condition that the relative humidity is not more than 85%.

When coating, the environment temperature is preferably between 5 and 38 ℃.

The optimal time is selected for coating, namely the time from 3 hours after sunrise to 3 hours after sunrise (indoor operation is not limited).

In the following cases, construction is generally impossible, and protective measures are needed if construction is needed:

in an environment with rain, fog, snow and large dust, construction in the open air is prohibited. The surface of the steel plate should not be dewed during coating, and should be protected from rain within 4 hours after coating.

The coating may be contaminated by dust, oil, salt and corrosive media.

When the light of the construction operation environment is seriously insufficient.

Safety measures and fireproof and explosion-proof tools are provided.

The painting interval time has great influence on the quality of the coating, and the interval time is properly controlled, so that the adhesion between the coatings and the comprehensive protection performance of the coatings can be enhanced.

The design notes the locations that are not painted.

Shielding before coating:

the parts which are forbidden to be painted may be influenced during construction, and shielding protection is carried out before construction. The part with larger area can be pasted with paper and pasted firmly with adhesive tape, and the part with smaller area can be pasted with adhesive tape completely.

The painting personnel engaged in the project must have the working experience of engaging in similar painting projects for more than half a year and obtain the on-duty certificate of painting.

The paint of the project must have a certificate of a national authority inspection department.

Painting position is needed to be repaired after the steel plate is installed:

exposed portions of the joint and fasteners, such as high strength bolt enamel portions.

A construction site welding area:

the paint part of a factory is frequently knocked off, and the rust-proof primer is coated in one step.

The painted paint film is uniform, flat, plump and glossy, and has no defects of undercut, crack, peeling, pin hole and the like. The thickness of the coating is measured by a magnetic thickness gauge, and the total thickness meets the relevant design requirements.

And step nineteenth, finished product inspection, namely performing partial sampling inspection on the finished product, labeling according to a construction drawing after the sampling inspection is qualified, protecting the packaged finished product, coating a protective film on the edge-processed groove, and paying attention to no collision.

The parts are corrected and formed, the assembled semi-finished products are stacked, and the cushion points and the stacking quantity are reasonable so as to prevent bending and deformation.

The treated friction surface should take oil-proof and damage-proof measures.

The parts, semi-finished products (hollow ball, bolt ball and accessories) and assembly parts coated with the anticorrosive paint need to be prevented from being collided, and if the parts, the semi-finished products and the assembly parts are collided, the parts, the semi-finished products and the assembly parts are repaired by the anticorrosive paint.

And step twenty, loading and sending.

The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may occur to those skilled in the art without departing from the principle of the invention, and are considered to be within the scope of the invention.

Claims (10)

1. A welding process of H-shaped steel is characterized in that:

the method comprises the steps of firstly, blanking and cutting flange plates and webs in a classified mode;

step two, H-shaped steel is pre-assembled, the site is prepared, the construction site must be a tamping site, the pre-assembly is carried out on a solid and stable pre-assembly platform or a jig frame, and the levelness of a supporting point is as follows:

the area is less than or equal to 300-1000m2, and the allowable deviation is less than or equal to 2 mm;

the area is less than or equal to 1000-1500m2, and the allowable deviation is less than or equal to 3 mm;

various conditions in the pre-assembly are controlled according to the size of a construction drawing, the central lines of all rod pieces are intersected at the center of a node and are completely in a free state, external force is not allowed to forcibly fix the rod pieces, and no matter a column, a beam and a support are supported, no less than two supporting points are needed for a single rod piece;

the center line of the control reference of the pre-assembled steel plate is clearly marked and is consistent with the platform reference line and the ground reference line; in the whole process of pre-assembling on the jig frame, the steel plate can not be directly corrected and cut on the jig frame by flame or mechanical means or the like, or ballast, impact and hammer by using a heavy object;

assembling the H-shaped steel, and assembling the welded H-shaped steel on an H-shaped steel automatic assembling machine of an H-shaped steel production line;

the web and the flange plate are subjected to local unevenness inspection before assembly;

before assembling the I-shaped structure, oil rust and other dirt in four main welding seam areas are required to be removed, the derusting width of a web plate is generally 20-30mm, and the derusting width of a cover plate is not less than the thickness of the web plate plus 50 mm;

assembling an H-shaped steel on an automatic H-shaped steel assembling machine;

checking the assembly precision, wherein the position of a machine head of the assembling machine is adjusted during assembly, and measuring the assembly deviation of the H-shaped steel while assembling;

welding H-shaped steel, wherein four main seams of the H-shaped steel are welded by adopting submerged arc welding on an H-shaped steel production line; welding the lower left corner, welding the upper right corner, actually welding the lower right corner, and finally welding the upper left corner;

step six, weld joint UT detection, appearance size inspection and weld joint appearance inspection;

seventhly, H-shaped steel is corrected, deformation correction is carried out on the H-shaped steel through a flange straightening machine, the end face is milled after correction, the end face is guaranteed to be flat, appearance size inspection is carried out after the end face is milled, and whether deformation occurs in the H-shaped steel is checked;

drilling holes at two ends of the H-shaped steel, and allowing punching when the quality, thickness and aperture of certain materials are proved and brittleness is not caused after punching; when drilling, checking the position of the web plate, wherein the offset of the scribing is less than or equal to 1mm, and selecting different drill bit forms according to different partition plate thicknesses; the original 200mm datum line is used as the standard for drilling; all common structural steel with the thickness below 5mm allows punching, and the secondary structural steel with the thickness less than 12mm allows punching; on the punched hole, welding (groove shape) cannot be carried out subsequently, and welding construction can be carried out unless the material still retains considerable toughness after punching is proved; generally, when the hole to be punched is drilled to be larger, the punched hole is required to be smaller than the specified diameter by 3 mm;

step nine, derusting a steel structure: the rust removal grade needs to meet the requirements of the design of a drawing;

various priming paints, intermediate paints and finishing paints have good priming compatibility, including performance matching, hardware matching, drying humidity matching and the like; after the rust removal is qualified, coating rust-proof primer twice, coating finish once on site, and coating finish once on the local part of the damaged part of the paint surface after the installation is finished, wherein the total thickness of a paint film is not less than 125 mu m;

the color of the finish paint is required to meet the requirements of drawings; the humidity of the coating construction environment is preferably constructed under the condition that the relative humidity is not more than 85 percent; when coating, the environment temperature is preferably between 5 and 38 ℃; selecting the optimal time for coating, namely, after sunrise for 3 hours, the time is within 3 hours after sunrise (indoor operation is not limited);

in the following cases, construction is generally impossible, and protective measures are needed if construction is needed: construction outdoors is prohibited in environments with rain, fog, snow and large dust; the surface of the steel plate should not be dewed during coating, and should be protected from rain within 4 hours after coating; the coating can be polluted by dust, oil stain, salt and corrosive media; when the light of the construction operation environment is seriously insufficient; under the conditions of safety measures and fireproof and explosion-proof tools and instruments; the painting interval time has great influence on the quality of the coating, and the interval time is properly controlled, so that the adhesion between the coatings and the comprehensive protection performance of the coatings can be enhanced;

shielding before coating: shielding and protecting parts which may affect the paint coating prohibition during construction before construction; the part with larger area can be pasted with paper and firmly pasted with adhesive tape, and the part with smaller area can be completely pasted with adhesive tape; coating personnel engaged in the project must have the working experience of engaging in similar coating projects for more than half a year and obtain the coating on duty certificate;

step ten, finished product inspection, namely performing partial selective inspection on the finished product, labeling according to a construction drawing after the selective inspection is qualified, packaging the finished product, paying attention to protection, coating a protective film on the edge-processed groove, and paying attention to no collision;

and step eleven, loading and sending.

2. The welding process of H-shaped steel according to claim 1, characterized in that: the method also comprises a raw material factory inspection link, wherein the factory inspection is carried out before blanking of the flange plate and the web plate, and the inspection process comprises material quality certification and inspection of material identification and material allowable deviation; the materials can be put into use after being inspected to be qualified;

when the surface of the steel has defects such as rust, pockmark or scratch, the depth of the steel is not more than the negative deviation value 1/2 of the thickness of the steel, otherwise, the steel cannot be used;

except that the factory quality certificate of the production factory must be provided, and should be under the contract requirement and the relevant existing standard in the first prescription, prison's witness, carry on witness sampling, sample sending, inspection and acceptance, make the inspection record; and providing inspection reports to the first party and the proctoring;

the use of welding rods with falling flux coatings or rusty core wires, welding fluxes which are moistened and caked or are melted and rusty welding wires is strictly forbidden; the surface of the stud used for stud welding must not affect the defects of cracks, streaks, dents, burrs and the like used;

the welding materials should be managed in a centralized way, a special warehouse is established, and the warehouse needs to be dried and well ventilated; the coating meets the design requirements and is stored in a special warehouse, and the coating which is overdue, deteriorated and failed by agglomeration cannot be used.

3. The welding process of H-shaped steel according to claim 2, characterized in that: the steel plate is preliminarily leveled after being inspected to be qualified when entering a factory, and raw materials after being inspected to be qualified are placed into a steel plate leveling machine to be leveled, so that the cutting quality and the blanking precision are prevented from being influenced by the unevenness of the steel plate; after the steel is leveled, lofting and material marking are firstly carried out, and 1:1, lofting, wherein the actual size of each steel plate is determined according to a design drawing during lofting; manual lofting is carried out on a flat lofting platform, and all steel plates for lofting are required to be released in a proportion of 1: 1; when materials are numbered, the welding seams of the H-shaped wing plates and the web plates cannot be arranged on the same cross section, and are staggered with each other by more than 200mm and staggered with the partition plates by more than 200 mm; the material receiving mode adopts a large plate material receiving mode as much as possible.

4. The welding process of H-shaped steel according to claim 3, characterized in that: the shrinkage (including the on-site welding shrinkage) and the required machining allowance such as cutting and end milling are reserved for lofting and material marking:

milling end allowance: each side of the sheared and processed material is generally added with 3-4 mm, and each side of the sheared and processed material is added with 4-5 mm;

cutting allowance: the width of the automatic gas cutting slot is 3mm, and the width of the manual gas cutting slot is 4 mm;

the welding shrinkage is given by the process according to the structural characteristics of the steel plate;

the material must be marked with the angle of the bevel and the direction of the blunt edge.

5. The welding process of H-shaped steel according to claim 1, characterized in that: the flange plate and the web plate are conveyed through different conveying devices again after blanking and cutting of the flange plate and the web plate are finished, the flange plate and the web plate are stopped again through a numerical control stop mechanism after reaching a specified position until the conveying mechanism conveys a second flange plate and the web plate, then the two flange plates are butted together, the two web plates are butted together, then the two flange plates and the web plate are pushed to one side of the station through a transverse pushing mechanism, and then welding of the joints of the two web plates and the two flange plates is started through a submerged arc welding machine; the double-sided butt weld which requires penetration of the butt weld is welded on one side, the weld root defect is thoroughly eliminated before the other side is welded until the metal luster of the weld joint is exposed, the welding can be carried out, but the back chipping is not allowed under the condition that the submerged arc automatic welding is adopted and the penetration of the weld joint can be ensured.

6. The welding process of H-shaped steel according to claim 5, characterized in that: adopting butt groove welding seam of a steel backing plate on the back, wherein the joint between the backing plate and a base material must be tight, and the welding metal and the backing plate should be completely fused; the method comprises the following steps that steel plates with different thicknesses are butted, one side of a thick plate is processed into a gentle transition shape, when the plate thickness difference exceeds 4mm, one side of the thick plate is processed into an inclination of 1: 2.5-1: 4, and the thickness of the butted part is equal to that of a thin plate;

butt welding, except special designation, should make the welding seam surplus height minimum, the surplus height value must not exceed 3mm, and peaceful transition to the surface of parent metal;

and after the welder finishes welding, cleaning the welding line, removing welding slag and welding spatter, carefully checking the appearance quality of the welding line, submitting to inspection after the welding line is qualified, and printing a steel seal of the welder near the qualified welding line.

7. The welding process of H-shaped steel according to claim 6, characterized in that: the flange plate and the web plate are continuously conveyed forwards through the conveying device after welding at the position is completed, the conveying is stopped after a certain distance is carried out, then the ultrasonic flaw detector is arranged in the middle of the conveying device to carry out UT detection, the UT detection is carried out forwards continuously after being qualified, and when the detection is unqualified, the corresponding unqualified flange plate or web plate is detached to repair the weld defects.

8. The welding process of H-shaped steel according to claim 7, characterized in that: after nondestructive testing is carried out on a welding line, when the overproof defect occurs, a welder cannot handle the defect freely, and needs to report that a welding technician checks the reason in time, and then a repair process measure is set and can be handled;

for the cracks in the weld metal, determining the boundary range of the cracks by applying a nondestructive testing method before repairing; drilling crack-stopping holes in front of two ends of the crack, and removing the crack and welding seams or base materials of which the two ends are 50mm respectively; weld seam size, recess, undercut exceed standard, should carry on the repair welding; polishing the generated welding beading and welding line with a grinding wheel until the welding beading and the welding line are in smooth transition with the base metal;

when the defects are eliminated, the gouging groove is processed into a groove with four side bevel angles larger than 10 degrees, the surface is trimmed, the gouging carburized layer is ground, and if necessary, a penetration flaw detection or magnetic particle flaw detection method is applied to determine whether the cracks are eliminated;

adopting the original welding method and the process regulation to perform repair welding; when the original submerged-arc welding seam has defects, a low-hydrogen welding rod is adopted for repair welding; arc striking is carried out in the groove during repair welding, and arc pits are filled during arc extinguishing; joints among welding layers of the multi-layer welding are staggered, the length of a welding line is not less than 100mm, and when the length of the welding line exceeds 500mm, a segmented welding-back method is adopted; continuously welding the repaired part; if the welding is interrupted, post-heating and heat-preserving measures are adopted to prevent cracks from generating, and after the secondary welding is checked and confirmed to have no cracks, the repair welding can be continued by using a penetration flaw detection or magnetic particle flaw detection method; the preheating temperature of the weld joint repair is higher than that of normal welding under the same condition, and whether post-welding dehydrogenation treatment is carried out or not is determined according to the actual condition of the engineering node; the number of times of repairing the same part of the welding seam is not more than 2; repairing the unqualified parts for two times, and re-formulating a repair scheme to be approved by an engineering technical responsible person and reported to be executable after being approved by a supervision engineer; the repair welding line should be filled with the repair construction record and the nondestructive testing report before and after repair as the project acceptance and filing data.

9. The welding process of H-shaped steel according to claim 8, characterized in that: the conveying device drives the flange plates or the web plates to continue to convey forwards and convey the flange plates or the web plates to the position of the strip steel leveling machine for leveling.

10. The welding process of H-shaped steel according to claim 1, characterized in that: the method also comprises the step of drilling the web, wherein after the step one is finished, the web is conveyed forwards continuously through the conveying device and conveyed to the position of the drilling machine for hole turning, the drilling is preferentially adopted when the web is drilled, and the punching is allowed to be adopted when the quality, thickness and aperture of certain materials are proved and brittleness is not caused after the punching; when drilling, checking the position of the web plate, wherein the offset of the scribing is less than or equal to 1mm, and selecting different drill bit forms according to different partition plate thicknesses; the original 200mm datum line is used as the standard for drilling;

all common structural steel with the thickness below 5mm allows punching, and the secondary structural steel with the thickness less than 12mm allows punching; on the punched hole, welding (groove shape) cannot be carried out subsequently, and welding construction can be carried out unless the material still retains considerable toughness after punching is proved; generally, when the hole to be punched is drilled to be larger, the punched hole is required to be smaller than the specified diameter by 3 mm;

after drilling, welding web studs, and carefully cleaning welded junctions before welding; the lower part of the welding arc is more than or equal to 20mm, and the upper part is more than or equal to 40 mm; the welding wire is H08Mn2SiA, and the welding flux is SH 331;

when adjusting the voltage: a. arcing is 40-42V b, 54V c after adding the flux, 50-51V d after normal welding, and is reduced to 48V when the surface is about 10 mm;

the non-molten nozzle electroslag welding adopts bilateral symmetry, and 6 welding machines are simultaneously welded;

the stud used in the project is qualified through the identification test of the welding end before leaving the factory, and can be used; the storage of the stud is ensured to be oil-free and rust-free; the protection ceramic ring should be stored to avoid being affected with damp and oil stain, and should be baked for about 2 hours at 120 ℃ before use;

the stud is welded by a special welding machine; manual welding is only used for local repair;

before construction operation every day, 2 studs are firstly welded on the same material (the thickness can be changed by 25%) as the steel plate in a test mode, then a 30-degree bending test is carried out, and if the extrusion welding leg reaches 360 ℃ and no heat influence area cracks exist, formal welding can be carried out;

after the stud is welded, uniform extrusion welding feet are required to be arranged within the range of 360 degrees, and other defects such as cracks and the like are avoided;

100 welded studs are used as a batch, 1% of the welded studs are spot-checked to carry out hammer knock test, the bending angle is 30 degrees, and if the extrusion welding leg has no defects such as cracks, the welded studs are considered to be qualified;

in the knock test, 2 sheets are inspected again when the test fails, and if 1 sheet fails to pass, the batch is inspected completely or re-welded completely.

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