CN-121988824-A - Anti-seismic high-efficiency welding method for solid hot-pressing direct-connection steel bars

CN121988824ACN 121988824 ACN121988824 ACN 121988824ACN-121988824-A

Abstract

The invention discloses a solid hot-pressing direct-connection steel bar anti-seismic efficient welding method, and belongs to the technical field of constructional engineering. The method comprises the steps of steel bar end surface pretreatment, coaxial centering clamping, sectional flame heating, axial pressurizing upsetting, natural cooling and pressure relief, wherein carbonization flame is adopted to convert neutral flame to sectional heating, the temperature of the steel bar is controlled to be 1150-1250 ℃, and 30-40 MPa pressure is applied to form a non-molten pool solid metallurgical bonding joint. The invention solves the problems of poor earthquake resistance, more defects, low efficiency, large pollution and the like of the traditional steel bar connection, the joint defect rate is lower than 0.5 percent, the qualification rate is not lower than 98 percent, no welding smoke or arc light is generated, the noise is less than or equal to 65dB, the construction success rate of the complex environment is more than or equal to 95 percent, and the invention is suitable for the steel bar connection of high-rise and earthquake-resistant buildings.

Inventors

WANG FAFEI
WANG PAN
ZHANG LEI
FU ENJIE
XU HUAZHONG
DING TONGXIN
XING LEI
Han Jiuchun
YE HONG
PANG SHIPENG
HU CAIQING
JIANG TINGTING

Assignees

安徽建工交通航务集团有限公司
安徽建工王家坝建设投资有限公司

Dates

Publication Date: 20260508
Application Date: 20260326

Claims (10)

1. The solid hot-pressing direct-connection steel bar anti-vibration efficient welding method is characterized by comprising the following steps of: S1, preprocessing the end face of the steel bar, namely cutting the end face of the steel bar to be smooth, removing oxide skin, rust and greasy dirt in the end face and end head areas, chamfering the end part of the steel bar, and controlling the perpendicularity deviation between the end face and the axis of the steel bar, the end face clearance and the axis bending angle; s2, centering and clamping the steel bars, namely symmetrically clamping the steel bars to be welded by adopting a V-shaped clamp, and calibrating the concentricity of the axes of the two steel bars and the parallel end surfaces of the two steel bars by using a laser centering instrument or a dial indicator, so that the axes of the steel bars in the whole subsequent heating and pressurizing process are kept to be free from offset; S3, heating the joint of the steel bars by using a segmented flame, namely, firstly, intensively heating the joint of the steel bars by using a carbonization flame to prevent the end face from oxidizing, and after the joint gap is completely closed, switching to uniformly and repeatedly heating the joint by using a neutral flame at two sides of a pressure welding surface, and controlling the temperature of the end face of the steel bars at 1150-1250 ℃; S4, axial pressurizing and upsetting, namely applying axial pressure of 30-40 MPa to the steel bar to enable the end face of the steel bar to generate plastic deformation and close, and diffusing and recrystallizing metal atoms at high temperature and high pressure to form a solid metallurgical bonding interface without a molten pool and inclusions; S5, naturally cooling and releasing pressure, namely releasing pressure after the steel bar joint is cooled to 400-500 ℃, and dismantling the clamp to finish welding, wherein water cooling, air cooling and any forced rapid cooling mode are forbidden to be adopted in the whole welding process.
2. The method for vibration-resistant and efficient welding of solid hot-pressed direct-connection steel bars according to claim 1, wherein in the step S1, steel bar blanking is performed by adopting toothless saw cutting, a steel bar cutting machine is forbidden to be used, the compression amount of a joint is 1.0-1.2 times of the diameter of the steel bar, the deviation of the perpendicularity of an end face and an axis is not more than 3mm, the gap between the end face and the axis is controlled to be 3-5 mm, the bending angle of the axis is not more than 3 degrees, and the specification, the length and the use position of the steel bar are marked after cutting.
3. The method for vibration-resistant and efficient welding of solid hot-pressed direct-connection steel bars according to claim 1, wherein in the step S1, the chamfer angle of the end parts of the steel bars is 15-30 degrees, the end faces are polished unidirectionally along the axis of the steel bars until the end faces are flat and vertical, continuous metallic luster is exposed, rust and oil dirt in the range of 100mm of the end heads are removed by polishing, polishing treatment is completed on the same day, and assembly and welding are completed within 60 minutes after polishing.
4. The method for high-efficiency welding of solid hot-pressed direct-connection steel bars according to claim 1, wherein in the step S3, the oxy-acetylene ratio of carbonization flame is 0.85-0.95, the oxy-acetylene ratio of neutral flame is 1-1.1, the acetylene pressure is controlled to be 0.05-0.1 MPa, the oxygen pressure is controlled to be 0.3-0.5 MPa, a multi-nozzle ring pipe heater is adopted for heating, the inner flame completely wraps the steel bar joints, the flame center is always aligned with the steel bar weld center in the heating process, and if tempering occurs before the gap is closed, the end face must be polished again and the rear part must be welded again.
5. The method for vibration-resistant and efficient welding of solid hot-pressed direct-connection steel bars according to claim 1, wherein in the step S3, when neutral flame heating is performed, the moving speed of a welding torch is 50-80 mm/min, the heating range is a region which takes a press welding surface as a center and has double steel bar diameters on both sides, and the temperature of the end face of the steel bar in the heating process is not higher than 1150-1250 ℃.
6. The method for welding the solid hot-pressed direct-connection steel bars with high vibration resistance and high efficiency according to claim 1, wherein in the step S4, axial pressing is performed according to a principle of firstly slowing down and secondly quickly, the pressing speed is firstly 0.5 MPa/S-1 MPa/S, then the pressing speed is increased to 2 MPa/S-3 MPa/S, the bulge diameter of a pressing part is not smaller than 1.4 times of the steel bars, the length of an upsetting area is not smaller than 1.2 times of the steel bars, and the axial pressing force is uniformly transmitted through a hydraulic clamp.
7. The method for vibration-resistant and efficient welding of solid hot-pressed direct-connection steel bars according to claim 1, wherein in the step S4, after pressurization is completed, flame is used for blowing and baking the surface of an upsetting region for 3-5 seconds, micro cracks of joints are eliminated, the upsetting region is smooth and stable in shape, no protrusions and collapse are caused, heating is stopped immediately after blowing and baking, and coarse grains caused by overheating of the upsetting region are prevented.
8. The method for welding the solid hot-pressed direct-connection steel bars in the anti-seismic efficient mode according to claim 1, wherein appearance inspection and mechanical performance inspection are carried out on the joint after welding is completed, the appearance inspection requires that two steel bars are concentric, the size of an upsetting area reaches the standard, no crack exists on the surface, the mechanical performance inspection requires that the tensile strength of the joint reaches more than 95% of the tensile strength of a base metal, the joint meets the highest requirements of building anti-seismic fortification categories, brittle fracture does not occur under seismic reciprocating load, and the fatigue resistance of the joint is superior to that of a traditional arc welding and mechanical connecting joint.
9. The method for high-efficiency anti-vibration welding of the solid hot-pressed direct-connection steel bar according to claim 1, wherein the whole welding process requires no welding smoke and no arc light radiation emission, the operation noise is controlled below 65 dB, and welding consumables such as welding rods and protective gas are not needed.
10. The method for welding the solid hot-pressed direct-connection steel bars with high vibration resistance and high efficiency is characterized in that the prepared steel bar joint meets the welding requirements that the internal defect rate of the joint is lower than 0.5%, the one-time welding qualification rate is not lower than 98%, the construction success rate of the joint is not lower than 95% in dense steel bar joints, high altitude, narrow space and humid and strong wind environments, and the metallographic structure of the joint is a uniform and fine recrystallized structure without defects of air holes, slag inclusion, unfused fusion and overburning structure.

Description

Anti-seismic high-efficiency welding method for solid hot-pressing direct-connection steel bars Technical Field The invention relates to the technical field of constructional engineering, in particular to a solid-state hot-pressing direct-connection steel bar anti-seismic efficient welding method. Background Along with the development of the building industry to high-rise, large-span and complicated directions, the steel bar connection technology becomes a key link of structural construction, and directly influences the bearing capacity, anti-seismic safety and construction efficiency of a building structure. The current mainstream reinforcement connection technology mainly comprises an arc welding technology, a mechanical connection technology and a traditional gas pressure welding technology, and the technology has a plurality of defects in practical engineering application: 1. The traditional arc welding, mechanical connection and molten state pneumatic welding are easy to cause brittle failure of the joint under the action of earthquake reciprocating load, and cannot meet the earthquake-resistant reliability requirements of high-rise, large-span and complex structures; 2. The construction efficiency is low, the energy consumption is high, the traditional process is complicated in working procedures, the heating time is long, the consumption of consumable materials such as welding rods, protective gas, fuel gas and the like is large, the equipment maintenance is frequent, and the comprehensive construction cost is high; 3. The welding quality is unstable, the joint is easily affected by the operating environment and the technical level of personnel, the welding seam is easy to generate defects such as slag inclusion, unfused, air holes and the like, the defect rate is as high as 8-12%, and the joint strength discreteness is large; 4. the environmental adaptability is poor, namely the construction success rate is only about 60 percent under the complex working conditions of dense reinforcement nodes, high altitude, narrow space, moist, strong wind and the like; 5. The traditional arc welding generates a large amount of welding smoke and strong arc radiation, the operation noise reaches more than 85 dB, and the health of constructors is endangered and the site environment is polluted. The existing closest traditional air pressure welding technology adopts single flame to continuously heat, and upsets and pressurizes the end face of the steel bar after the end face of the steel bar is heated to a molten state, so that the problems of uneven temperature distribution, coarsening of crystal grains, multiple defects of a molten pool, rough technological parameters and the like exist, and the steel bar connection with high vibration resistance, high efficiency, environmental protection and stable quality is difficult to realize at the same time. Based on the above, the invention aims to provide a solid hot-pressing direct-connection steel bar anti-vibration high-efficiency welding method, which solves the defects existing in the prior art. Disclosure of Invention The invention aims to provide a solid hot-pressing direct-connection steel bar anti-vibration high-efficiency welding method for solving the defects. In order to achieve the above object, the present invention provides the following technical solutions: the invention provides a solid hot-pressing direct-connection steel bar anti-seismic efficient welding method, which comprises the following steps of: S1, preprocessing the end face of the steel bar, namely cutting the end face of the steel bar to be smooth, removing oxide skin, rust and greasy dirt in the end face and end head areas, chamfering the end part of the steel bar, and controlling the perpendicularity deviation between the end face and the axis of the steel bar, the end face clearance and the axis bending angle; s2, centering and clamping the steel bars, namely symmetrically clamping the steel bars to be welded by adopting a V-shaped clamp, and calibrating the concentricity of the axes of the two steel bars and the parallel end surfaces of the two steel bars by using a laser centering instrument or a dial indicator, so that the axes of the steel bars in the whole subsequent heating and pressurizing process are kept to be free from offset; S3, heating the joint of the steel bars by using a segmented flame, namely, firstly, intensively heating the joint of the steel bars by using a carbonization flame to prevent the end face from oxidizing, and after the joint gap is completely closed, switching to uniformly and repeatedly heating the joint by using a neutral flame at two sides of a pressure welding surface, and controlling the temperature of the end face of the steel bars at 1150-1250 ℃; S4, axial pressurizing and upsetting, namely applying axial pressure of 30-40 MPa to the steel bar to enable the end face of the steel bar to generate plastic deformation and close, and diffusing and recrystall