1.What is the technical principle of laser zinc removal technology for galvanized layer?
This technology is mainly based on the photothermal effect of laser. When the laser beam irradiates the surface of the galvanized layer, the zinc layer absorbs the energy of the laser and converts it into heat energy, causing the temperature of the zinc layer to rise rapidly. Since the melting point of zinc is 419℃ and the boiling point is 911℃, which is relatively low, after absorbing a large amount of laser energy, the temperature will quickly rise above the boiling point, causing the zinc to gasify and escape as zinc vapor. At the same time, the energy of the laser will also produce a certain impact force, causing part of the zinc layer to be peeled off and fall off from the surface of the substrate. In this process, the key is to control the energy density of the laser and keep the substrate temperature within a suitable range, generally between 419℃ and 900℃, so that the oxidation of the substrate iron can be avoided while removing the zinc layer, ensuring the integrity of the substrate.
2.What are the components of laser zinc removal technology equipment for galvanized layer?
Laser generation system: It is the core component used to generate high-energy-density laser beams. Common ones include fiber lasers, etc. The laser power, wavelength, pulse width and other parameters can be adjusted according to different process requirements.
Beam transmission and focusing system: The laser beam is transmitted to the part to be treated through components such as optical fiber or reflectors, and the laser beam is focused using a focusing lens to increase the energy density and ensure that the galvanized layer can be effectively removed.
Control system: Mainly used to control the output parameters, scanning speed, scanning path, etc. of the laser. It can also cooperate with the mechanical motion system to realize automated zinc removal operation and ensure the accuracy and consistency of the zinc removal process.
Mechanical motion system: including workbench, guide rails, motors, etc., which can drive the workpiece or laser head to move, so that the laser can cover the entire area that needs zinc removal and realize large-area zinc removal operations.
3.What are the characteristics of laser zinc removal technology for galvanized layer?
High efficiency: Laser dezincification is fast and can remove a large area of galvanized layer in a short time, improving production efficiency.
Accuracy: The action area and energy of the laser can be accurately controlled to achieve local dezincification, which will not affect the parts that do not need dezincification, and is suitable for occasions with high precision requirements.
Environmental protection: No chemical agents are required, and no pollutants such as wastewater and exhaust gas are generated, which meets environmental protection requirements.
Good surface quality: The heat effect on the substrate during the dezincification process is small, and it will not cause serious deformation or damage to the substrate surface. Moreover, the surface is relatively clean and flat after dezincification, and subsequent processing is simple.
4.What are the application scenarios of laser zinc removal technology for galvanized layers?
Welding pretreatment: When welding galvanized steel plates, in order to avoid defects such as pores and spatter in the zinc layer during welding, it is necessary to remove the zinc layer at the welding site first. Laser zinc removal technology can accurately remove the zinc layer in the area to be welded, providing good conditions for subsequent welding.
Surface repair and modification: When the surface of the galvanized part is partially damaged or needs to be reprocessed, the laser zinc removal technology can be used to remove the zinc layer at the damaged part, and then other repair or modification treatments can be performed.
Cultural relic restoration: For some cultural relics with a zinc layer on the surface, if they need to be repaired or protected, laser zinc removal technology can remove the zinc layer or other contaminants on the surface without damaging the body of the cultural relic, which is convenient for further repair work.
5.What are the advantages of laser zinc removal technology for galvanized layers compared with other zinc removal technologies?
High precision: Laser zinc removal can achieve the removal of the galvanized layer in a specific area by precisely controlling the laser energy, scanning path and other parameters. It can accurately remove the zinc layer in the welding area and other areas that need to be processed without affecting other parts. It is very suitable for some occasions that require high precision in the position of zinc removal. Mechanical zinc removal methods, such as shot peening, are difficult to accurately control the range of zinc removal, which can easily cause large-area damage to the surface of the substrate, affecting the dimensional accuracy and surface quality of the substrate.
Good environmental protection: This technology does not require the use of chemical agents, and does not produce pollutants such as wastewater and exhaust gas during the zinc removal process, which is environmentally friendly. In contrast, chemical zinc removal usually requires the use of strong acid solutions such as hydrochloric acid to remove the zinc layer, which will produce a large amount of acidic wastewater. If not handled properly, it will cause serious pollution to the environment, and the wastewater will need to be specially treated later, which increases the cost and difficulty of treatment.
Little damage to the substrate: As long as the laser energy density and other parameters are reasonably controlled, the substrate can be removed while ensuring that the zinc layer is not damaged, and serious deformation, oxidation and other problems on the surface of the substrate will not occur. For example, vacuum baking to remove zinc requires heating the steel plate to a higher temperature, which may change the organizational structure of the substrate, thereby affecting the mechanical properties of the substrate.