Environment requirements and public's awareness about ecological brought increasingly new demands for the world cleaning industry in recent years. Many cleaning methods came into life, laser cleaning technology is one of them.
Compared with mechanical cleaning way, chemical corrosion way and high-frequency ultrasonic, laser cleaning owes advantaged of high efficiency, high rapidity, low cost, low thermal load and low mechanical load on the workpiese, besides the cleaned powder can be recycled to ensure operators healthy and environment-friendly. Layers mixed by different thickness and compositions can be effictively cleaned by laser cleaning way even some that traditional way cannot meet. In addition, it is easy to reach automatic control and remote control by laser cleaning way.
The principle of laser cleaning is to reach interaction result between high-energy laser and cleaning surface and after this process, lightly vaporizes or the thermal expansion happens to detache material to be clean from the substrate thus achieving the purpose of cleaning and purifying the workpiece.
Laser power ranges from ten watts to several kilowattes, depending on the cleaning target. The laser can clean various dirt on the workpiece, such as degreasing, rust removal, paint removal, oxide coating and various coatings. Laser rust removal is a common application among them. The following describes the case of laser rail derusting.
Due to the year-round exposure to air, coupled with wind, sun, rain, snow and frost, the surface is prone to rust. In order not to affect the safe operation of the train, rail derusting is necessary.
In this case, experimental methods were used to test and evaluate the cleaning effect and cleaning efficiency of using fiber laser cleaning machines (MRJ-FL-C200A) to clean the rail rust layer.
(1) Cleaning system configuration
The specific system configuration of this cleaning experiment is shown in Table 1. The experiment will test and evaluate the cleaning effect of MRJ-FL-C200A cleaning machine equiped with IPG's YLPN-10-30*400-20-200 on the rail rust layer. The lasers all work in the pulse mode, and equipped with a numerically controlled platform or manipulator in different scanning methods and process parameters to meet the requirements of different surface cleaning requirements.
The actual physical map of the experimental system is shown in Figure 1.
1-mm to 100mm
Maximum Scan Angle
The rust layer on the rail surface actually contains two layers. One is a yellow rust layer of iron oxide (Fe2O3) on the surface of the oxide scale, and another is a deeper black rust layer.
(2) Cleaning parameter selection and cleaning effect
Next, we use the MRJ-FL-C200A laser cleaning machine for cleaning experiments. In order to obtain a better cleaning effect, the use of MRJ-FL-C200A laser cleaning is divided into two steps, the difference between these two steps is mainly the use of different laser power, the first step of the power slightly larger than second step. These are used to clean the rust layer in large areas; the second step is to reduce the power for more precise and fine rust removal. The specific parameter configuration is shown below.
The experimental results show that after two steps of high- and low-power cleaning, the yellow rust layer and the black rust layer on the rail surface are completely washed away, and the cleaned rail is bright and white, as shown below.
Use MRJ-FL-C200A to clean rail surface
By using MRJ-FL-C200A laser cleaning machine, yellow rust layer and black rust layer had been completely washed out from rail surface and reach the effect of keep substrate its oringal color.