Ceramic ring for stud welding and stud system

Abstract

The invention relates to a ceramic ring for stud welding and a stud system.The ceramic ring comprises a glass fiber reinforced thermal shrinkage film located on the outer layer and an ardealite-based ceramic layer located on the inner layer, the glass fiber reinforced thermal shrinkage film wraps the outer wall of the ardealite-based ceramic layer, and a thermal pore-foaming agent is added into the ardealite-based ceramic layer; and the inner wall of the ardealite-based ceramic layer is provided with a heat insulation layer and forms a spiral air guide groove. The stud system comprises a ceramic ring and a stud, the stud comprises a stud body and a stud head located at one end of the stud body, a copper foil electric arc guiding layer is formed on the top face of the stud head, an annular micro air cavity is formed in the portion, on the lower portion of the stud head, of the stud body, the annular micro air cavity is filled with smelting flux, and the annular micro air cavity is provided with an opening. And a thermal decomposition sealing film covers the opening. A double-air-curtain dynamic sealing system is constructed through the ceramic rings and the studs, the oxygen concentration of a molten pool area is reduced, the stud welding quality is improved, the ceramic rings are automatically disintegrated into micron-sized powder during welding, cleaning and recycling are not needed, and the construction efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of stud welding technology, and more specifically to a ceramic ring for stud welding and a stud system. Background Technology

[0002] When welding studs onto steel truss floor slabs, ceramic rings are typically used for auxiliary welding. These rings isolate oxygen and confine the molten pool. After welding, the ceramic rings must be manually cleaned, a cumbersome process. Current technology results in a high breakage rate after welding, with fragments embedding in the floor slab's gaps, requiring manual chipping and removal, severely impacting construction speed. Statistics show that welding a single stud generates approximately 15-20g of ceramic waste, resulting in over 1.2 tons of non-biodegradable waste per 10,000 square meters of construction area, with cleanup taking up 15%-20% of the total construction time.

[0003] Although existing recycling technologies (such as acid washing and screening processes) enable partial reuse, the processes are cumbersome and require specialized equipment (suspended baskets, neutralization tanks, etc.). The recycling process consumes a large amount of water, resulting in high wastewater treatment costs. Furthermore, damaged ceramic rings after screening still need to be landfilled, meaning environmental pollution is not fundamentally eliminated, making the recycling cost far exceed the intrinsic value of the ceramic rings. Some ceramic rings employ a detachable structural design, such as a spring-locking structure. These rings will fatigue and fail after a certain number of reuses, causing the overall cost to surpass that of purchasing new ceramic rings. Summary of the Invention

[0004] In view of the shortcomings of the existing ceramic rings that require recycling, the present invention first discloses a self-decomposing, non-recyclable ceramic ring for welding studs, which causes the welded ceramic ring to automatically disintegrate into micron-sized powder, which can be directly mixed into concrete to improve its density, eliminating the need for recycling and thus eliminating the ceramic ring cleaning and recycling process at the source.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A ceramic ring for stud welding includes a glass fiber reinforced heat shrink film on the outer layer and a phosphogypsum-based ceramic layer on the inner layer. The glass fiber reinforced heat shrink film covers the outer wall of the phosphogypsum-based ceramic layer, and a thermoporous agent is added to the interior of the phosphogypsum-based ceramic layer.

[0006] Furthermore, the composition of the phosphogypsum-based ceramic layer is as follows: phosphogypsum 60%, rice husk ash 25%, and starch glue 15%.

[0007] Furthermore, the thermoporic agent is azodicarbonamide.

[0008] Furthermore, the thermoporous agent is added at a rate of 10% in the phosphogypsum-based ceramic layer.

[0009] Furthermore, the inner wall of the phosphogypsum-based ceramic layer is provided with a heat insulation layer.

[0010] Furthermore, the heat insulation layer is made of nano-zirconia.

[0011] Furthermore, the inner wall of the phosphogypsum-based ceramic layer is provided with a spiral air guide groove.

[0012] Based on the ceramic ring with the above structure, the present invention also discloses a stud system, including the above ceramic ring and studs. The stud includes a stud body and a stud head located at one end of the stud body. A copper foil arc guiding layer is formed on the top surface of the stud head. An annular micro-cavity is provided on the stud body below the stud head. The interior of the annular micro-cavity is filled with molten flux. The annular micro-cavity has an opening, and the opening is covered with a thermal decomposition sealing film.

[0013] Furthermore, the smelting flux is CaF2-Al2O3-SiO2 flux, and the ratio of CaF2, Al2O3 and SiO2 is 60:30:10.

[0014] Furthermore, the thermal decomposition sealing film is made of polyvinyl alcohol.

[0015] The ceramic ring designed in this invention, when subjected to temperatures exceeding 350°C during welding, causes the thermogenic pore-forming agent in the inner phosphogypsum-based ceramic layer to decompose, resulting in a dramatic increase in the porosity of the inner layer. This leads to a zero structural strength, and the outer glass fiber reinforced heat-shrink film ruptures, ultimately causing the ceramic ring to disintegrate into powder. This powder requires no cleaning and can be directly mixed into the concrete used in floor decking construction, improving the concrete's density. Compared to existing ceramic ring technologies, this invention eliminates the need for cleaning and recycling, reducing construction time by more than 50%. When the ceramic ring designed in this invention is used for stud welding, the decomposition of the thermogenic pore-forming agent in the inner layer releases nitrogen gas. This nitrogen fills the gap between the ceramic ring and the stud, blocking oxygen penetration at the edge of the molten pool and enhancing oxygen isolation, thereby improving the welding quality of the stud. Attached Figure Description

[0016] Figure 1 This is a vertical sectional view of the ceramic ring in the embodiment; Figure 2 for Figure 1 Sectional view at point AA; Figure 3 This is a front view of the stud in the embodiment; Figure 4 for Figure 3 Sectional view at point BB.

[0017] Figure label: 1. Fiberglass reinforced heat shrink film; 2. Phosphogypsum-based ceramic layer; 3. Thermopolymer; 4. Insulation layer; 5. Air guide groove; 6. Stud body; 7. Stud head; 8. Copper foil arc guiding layer; 9. Annular micro-air cavity; 10. Thermal decomposition sealing film. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0019] This embodiment discloses a stud system for welding studs on floor decking. This solution is applicable to the welding of studs in building construction. The stud system includes studs and ceramic rings fitted onto the studs. The structure of the studs and ceramic rings is described below with reference to the accompanying drawings.

[0020] The ceramic ring structure in this embodiment is as follows: Figure 1 and Figure 2 As shown, the ceramic ring body adopts a double-layer structure design, with an inner layer being a degradable material and an outer layer being a heat-shrinkable film. Specifically, the inner layer of the ceramic ring is a ring-shaped phosphogypsum-based ceramic layer 2, and the outer periphery of the phosphogypsum-based ceramic layer 2 is covered with a layer of glass fiber reinforced heat-shrinkable film 1. In this embodiment, the composition of the phosphogypsum-based ceramic layer 2 is as follows: phosphogypsum 60%, rice husk ash 25%, and starch adhesive 15%. In this embodiment, the height of the ceramic ring is 25mm, the outer diameter of the ceramic ring is 23mm, and the inner diameter of the ceramic ring is 17mm. In this embodiment, the glass fiber reinforced heat-shrinkable film 1 is made of glass fiber reinforced PET, with a heat distortion temperature of 150℃. The thickness of the glass fiber reinforced heat-shrinkable film 1 in this embodiment is 0.2mm. Once heated, it will shrink and break, releasing the degradable material of the inner layer. In this embodiment, a thermoporous agent 3 is added to the interior of the phosphogypsum-based ceramic layer 2. A thermoporous agent is a material that forms pores by inducing phase separation through heating. Its core principle is to cause physical or chemical changes in the material through heating, resulting in phase separation of the system and the formation of a microporous structure. In this embodiment, the thermoporinizing agent 3 is azodicarbonamide, which is added to the phosphogypsum-based ceramic layer 2 at a ratio of 10% to ensure that the ceramic ring is heated to 350°C during stud welding, resulting in an inner layer porosity of >60%, thereby causing the phosphogypsum-based ceramic layer 2 to disintegrate and form micron-sized powder.

[0021] To improve corrosion resistance, floor decking typically features a galvanized layer. However, existing ceramic rings lack active heat insulation. During stud welding, the high welding temperature (generally >1300℃) far exceeds the evaporation point of the galvanized layer (907℃). The zinc oxide fumes generated by zinc evaporation not only pollute the environment but also weaken the corrosion resistance of the steel structure, requiring additional anti-corrosion treatment, which increases the total life-cycle cost. To avoid these problems, this embodiment also includes a heat insulation layer 4 on the inner wall of the phosphogypsum-based ceramic layer 2. The heat insulation layer 4 uses nano-zirconia (ZrO2, particle size 50nm) and has a thickness of 0.1mm. The heat insulation layer 4 reflects radiant heat, thereby protecting the galvanized layer on the steel structure.

[0022] Traditional ceramic rings rely solely on physical sealing to isolate oxygen from the molten pool, achieving an efficiency of only 85%-90%. During outdoor construction, airflow disturbances cause the oxygen concentration at the edge of the molten pool to reach 12%-15%, exceeding welding requirements (≤5%). This results in weld porosity exceeding 8%, uneven penetration (deviation ±12%), and shear strength fluctuations of ±8kN. Although some existing ceramic rings incorporate ventilation holes, the unstable air intrusion makes it difficult to completely resolve the problem, and the complex structure (such as an external fan) actually increases the construction burden. To improve the oxygen isolation effect in the molten pool, the ceramic ring in this embodiment also uses laser engraving to form spiral ventilation grooves 5 on the inner wall of the phosphogypsum-based ceramic layer 2. The ventilation grooves 5 are 0.5mm deep and 1mm wide, and seven ventilation grooves 5 can be set along the height of the ceramic ring. In this embodiment, the pyrolysis of the ceramic ring generates an auxiliary nitrogen barrier, and the ventilation grooves 5 guide the uniform release of nitrogen, which can improve the oxygen isolation effect.

[0023] The stud structure in the stud system of this embodiment is as follows: Figure 3 and Figure 4As shown, the stud includes a cylindrical stud body 6 and a stud head 7 located at one end of the stud body 6. The outer diameter of the stud head 7 is larger than the outer diameter of the stud body 6. In this embodiment, the stud body 6 is made of Q345B alloy steel, and its surface is provided with a galvanized layer with a thickness of 20±2μm, meeting the requirements of salt spray test >96h and no corrosion. The stud dimensions in this embodiment are designed according to common standard specifications, that is, the stud length is 100mm, the diameter of the stud body 6 is 16mm, and the diameter of the stud head 7 is 22mm. The top surface of the stud head 7 is formed with a 0.2mm thick copper foil arc guiding layer 8 by electrodeposition, which is used for arc guiding, and the conductivity is guaranteed to be ≥98%IACS (International Annealed Copper Standard). An annular micro-cavity 9 is provided on the stud body 6 below the stud head 7. The interior of the annular micro-cavity 9 is filled with molten flux, and the annular micro-cavity 9 has an opening covered with a thermal decomposition sealing film 10. In this embodiment, the annular micro-cavity 9 is located 10mm below the stud head 7. The height of the annular micro-cavity 9 along the length of the stud body 6 is 2mm, and the width of the annular micro-cavity 9 in the radial direction is 1.5mm. The annular micro-cavity 9 is filled with CaF2-Al2O3-SiO2 flux (60:30:10 ratio), with a particle size of 80-100 mesh, and a filling amount of 0.8g / stud. In this embodiment, the thermal decomposition sealing film 10 is a 0.1mm thick polyvinyl alcohol film (which can vaporize at 350℃), and the polyvinyl alcohol film is set to prevent flux leakage.

[0024] In this invention, the flux in the annular micro-cavity 9 of the stud decomposes at high temperature to produce CO2. The released CO2 gas forms the main protective gas curtain. Since CO2 density is greater than air, this descending gas curtain covers the core area of ​​the molten pool, effectively isolating it from oxygen. The thermoporous agent 3 in the ceramic ring decomposes at 350℃ to release N2, which acts as an auxiliary barrier. The N2 fills the gap between the ceramic ring and the stud, blocking oxygen penetration from the edges. This invention, by constructing a dual-gas curtain dynamic sealing system, can suppress the oxygen concentration in the molten pool area to near zero, completely eliminating defects such as porosity and spatter during welding and improving the welding quality of the studs. This invention also incorporates an active heat hazard barrier on the ceramic ring. The nano-zirconia coating inside the ceramic ring reflects 80% of radiant heat (reflecting infrared radiation in the 2-20μm band), controlling the temperature of the galvanized layer below 750℃ (Zn evaporation point 907℃), thus reducing the burn-off rate of the galvanized layer. The ceramic ring designed in this invention has a self-decomposition mechanism. The ceramic ring decomposes naturally during the stud welding operation. The high welding temperature (>350℃) causes the thermal pore-inducing agent 3 in the inner phosphogypsum-based ceramic 2 to decompose, resulting in a sharp increase in the porosity of the inner layer, which causes the structural strength to drop to zero. The outer glass fiber reinforced heat shrink film 1 ruptures and eventually disintegrates into powder, which can be directly mixed into concrete without cleaning and can also increase the density of concrete.

[0025] Based on the above-mentioned ceramic ring and stud structure, the construction method for stud welding is as follows: 1. Ceramic ring installation: Insert the self-disintegrating ceramic ring onto the stud body 6, and gently press to confirm that it fits the floor deck.

[0026] 2. Welding Operation: The welding torch is pressed vertically against the stud head 7, applying axial pressure. After energizing, the copper foil arc guiding layer 8 ignites an arc under low voltage, melting through the stud root. The CaF2-Al2O3-SiO2 flux in the annular micro-cavity 9 decomposes and releases CO2 at the high temperature of the arc (>1500℃), covering the core area of ​​the molten pool. When the temperature of the inner layer of the ceramic ring rises to 350℃ due to the welding action, the thermogenic agent 3 decomposes and releases N2, which diffuses spirally through the gas guide groove 5 to form an edge protection zone, which, together with the CO2 released from the annular micro-cavity 9 of the stud, isolates oxygen.

[0027] 3. Heat reflection control: The nano-zirconia coating reflects the heat during welding and presses it at ≤750℃ (zinc evaporation point 907℃), protecting the galvanized layer of the floor decking.

[0028] 4. Post-weld treatment: After welding, the inner layer of the ceramic ring has a porosity exceeding 60%, and the outer fiberglass-reinforced heat-shrink film 1 ruptures. Within 72 hours, the ceramic ring disintegrates into powder with a particle size ≤0.1mm. No manual intervention is required; the powder can be directly mixed into the concrete pouring layer. If it is necessary to accelerate the degradation of the ceramic ring in an emergency, a blowtorch can be used to heat the ceramic ring to 100℃±10℃ (for 30 seconds) at a distance of 100mm to trigger the hydrolysis reaction and accelerate the disintegration of the ceramic ring.

[0029] This invention achieves the following three major technological breakthroughs: 1. Simplified construction – the process is completed in two steps: placing the ceramic ring and welding the studs. After welding, there is no need to clean the ceramic ring, reducing the working time by more than 50%. 2. Military-grade quality – weld coverage angle reaches 360°, and shear strength fluctuation is close to zero; 3. Greening the entire chain – zero solid waste, intact coating, and sharp reduction in carbon emissions, turning industrial phosphogypsum from waste into treasure.

[0030] With the three-in-one innovation of "active gas protection - precise heat shielding - in-situ value enhancement of waste", the pollution, rework and high consumption problems in the steel structure welding field have been solved for decades.

[0031] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A ceramic ring for welding studs, characterized in that: It includes an outer layer of glass fiber reinforced heat shrink film and an inner layer of phosphogypsum-based ceramic layer. The glass fiber reinforced heat shrink film covers the outer wall of the phosphogypsum-based ceramic layer, and a thermoporous agent is added to the interior of the phosphogypsum-based ceramic layer.

2. The ceramic ring for welding studs according to claim 1, characterized in that: The composition of the phosphogypsum-based ceramic layer is as follows: phosphogypsum 60%, rice husk ash 25%, starch glue 15%.

3. A ceramic ring for welding studs according to claim 1, characterized in that: The thermo-porous agent used is azodicarbonamide.

4. A ceramic ring for welding studs according to claim 3, characterized in that: The thermoporous agent is added at a ratio of 10% in the phosphogypsum-based ceramic layer.

5. A ceramic ring for welding studs according to claim 1, characterized in that: The inner wall of the phosphogypsum-based ceramic layer is provided with a heat insulation layer.

6. A ceramic ring for welding studs according to claim 5, characterized in that: The heat insulation layer is made of nano-zirconia.

7. A ceramic ring for welding studs according to claim 1, characterized in that: The inner wall of the phosphogypsum-based ceramic layer is provided with a spiral air guide groove.

8. A stud system, characterized in that: The device includes a stud and a ceramic ring as described in any one of claims 1-7. The stud includes a stud body and a stud head located at one end of the stud body. A copper foil arc guiding layer is formed on the top surface of the stud head. An annular micro-cavity is provided on the stud body below the stud head. The interior of the annular micro-cavity is filled with molten flux. The annular micro-cavity has an opening covered with a thermal decomposition sealing film.

9. A stud system according to claim 8, characterized in that: The flux used is CaF2-Al2O3-SiO2 flux, with a ratio of 60:30:10 for CaF2, Al2O3, and SiO2.

10. A stud system according to claim 8, characterized in that: The thermal decomposition sealing film is made of polyvinyl alcohol.

Images