Study On Nondestructive And Synergistic Cleaning Of Rusted Steel Plate By Continuous Nanosecond Combined Laser

Continuous laser and nanosecond pulse laser have different main cleaning mechanisms when cleaning rusted steel plates.Therefore,when establishing the experiment of continuous nanosecond combined laser cleaning rusted steel plates,we should consider the respective properties and different combination modes of continuous laser and nanosecond pulse laser.In this paper,the cleaning characteristics of single system laser and the influence of the combination mode of continuous nanosecond combined laser on the cleaning effect,cleaning efficiency and surface morphology of rusted steel plate are studied.In terms of theoretical research,based on the physical properties and structural characteristics of the rust on the steel plate surface,the adsorption relationship between the rust on the steel plate surface and the substrate is established.Four mechanisms of laser cleaning are listed,including stripping mechanism,instantaneous surface heat treatment,ablation mechanism and phase explosion.Then the temperature rise model and stress model of continuous laser and nanosecond pulse laser are established.Based on the coupling effect between heat and force in the process of continuous laser and nanosecond pulse laser cleaning of rusted steel plate,a theoretical model of continuous laser and nanosecond pulse laser cleaning of rusted steel plate is established.In the aspect of simulation research,based on the theoretical model,the simulation models of rusted steel plate irradiated by continuous laser and nanosecond pulse laser are established,and the simulation research under the conditions of continuous laser and nanosecond pulse laser is carried out.Under the condition of continuous laser,the simulation results of continuous laser cleaning rusted steel plate with different power density are obtained,and the influence and variation law of laser parameters of continuous laser on temperature field are obtained.Under the condition of nanosecond pulse laser,the simulation results of nanosecond pulse laser cleaning rusted steel plate are obtained,and the variation law of nanosecond pulse laser stress field with time is obtained.In the aspect of experimental research,experiments of continuous laser,nanosecond pulse laser and continuous nanosecond combined laser cleaning rusted steel plates were carried out.The experiment of cleaning rusted steel plate with single system laser and continuous nanosecond combined laser was established.The cleaning characteristics of single system laser and the influence of continuous nanosecond combined laser on the cleaning effect,cleaning efficiency and surface morphology of rusted steel plate were studied.An optical system for cleaning rusted steel plate by 1064 nm continuous laser and1064 nm nanosecond pulse laser was established.An on-line temperature monitoring system with a point thermometer and a thermal imager was built,and the surface temperature changes of the rusted steel plate when reacting with the laser were recorded.After observing the surface morphology of the cleaned steel plate,a combination mode that improves the cleaning effect and cleaning efficiency without damaging the substrate is obtained.Nanosecond pulse laser is added in the process of continuous laser action with low power density.After the action of continuous laser,nanosecond pulse laser is used to repeatedly scan the area irradiated by continuous laser.It can effectively improve the cleaning effect and efficiency of rusted steel plate,and will not cause obvious damage to the substrate.