Laser cleaning Use fiber laser to remove the rust layer on the surface of the rails

Laser cleaning Use fiber laser to remove the rust layer on the rail surface

 In recent years, with the improvement of environmental protection requirements and the continuous enhancement of people's awareness of environmental protection, it has also brought new development opportunities to the cleaning industry around the world, and various cleaning technologies that are conducive to environmental protection have emerged. one of them. Compared with traditional cleaning methods such as traditional mechanical cleaning, chemical corrosion cleaning, and high-frequency ultrasonic cleaning, laser cleaning has the advantages of high efficiency, fastness, low cost, low thermal and mechanical load on the workpiece, non-contact and non-damage, and laser cleaning. The cleaned waste can be recycled to ensure the health and safety of the environment and operators. Laser cleaning can remove coatings of various thicknesses and compositions, and can even clean problems that cannot be solved by traditional cleaning methods. In addition, the laser cleaning process is easy to realize automatic control and remote control.

     The principle of laser cleaning is to use the interaction between the high-energy laser and the surface material of the workpiece to be cleaned. Under the action of the high-energy laser, the cleaned material is instantly vaporized or thermally expanded and falls off the substrate, thereby achieving the purpose of the workpiece cleaning and purification process.

     The power used for cleaning varies from ten watts to several kilowatts, and the choice of specific power depends on the cleaning goal. Laser can clean all kinds of dirt on the workpiece, such as degreasing, rust, paint, oxide layer and various coatings. Among them, laser rust removal is already a common application. The following introduces the case of laser rail rust removal.

Rail rust removal case

      Because the rails are exposed to the air all the year round, coupled with wind, sun, rain, snow and frost, the surface of the rails is easy to rust. In order not to affect the safe operation of the train, it is very necessary to derust the rails.

In this case, the cleaning effect and cleaning efficiency of two types of fiber lasers for cleaning the rust layer of rails were tested and evaluated by experimental methods.

(1) Cleaning system configuration

      In this cleaning experiment, the cleaning effects of 1000W and 200W fiber lasers on the rust layer of rails. The lasers all work in pulse mode, equipped with IPG medium power scanning galvanometers, and equipped with CNC platforms or manipulators in different scanning methods and process parameters to meet the requirements of different surface cleaning.

(2) Cleaning parameter selection and cleaning effect

      The cleaning experiment was first performed using a 1000W laser. The specific cleaning parameter configuration selected in the experiment.

Figure: Using a 1000W laser only cleaned the yellow rust layer on the surface of the rail, while the deeper black rust layer still existed. When optimizing the focusing spot at 0.8mm, a very good cleaning effect can be achieved.

Next, we used a 200W laser for the cleaning protocol. In order to obtain a better cleaning effect, the cleaning with a 200W laser is divided into two steps. The main difference between these two steps is the laser power used. The power of the first step is slightly larger, which is used to clean the rust layer in a large area; The second step is reduced power for more precise and finer rust removal. specific parameter configuration.

The experimental results show that after the two steps of cleaning, one high and one low, the yellow rust layer and black rust layer on the surface of the rail are completely cleaned, and the cleaned rail is white and bright, as shown in the figure.

Using a 200W laser to clean, the yellow rust layer and black rust layer on the surface of the rail are completely cleaned, and the cleaning effect of the color of the substrate body is obtained.

Experimental results

      From the experimental results, it is not difficult to see that the 1000W laser has a very good cleaning effect for removing the shallow Fe2O3 yellow rust layer on the surface of the rail, which is more efficient than using the 200W laser. For cleaning deeper black rust layers, a 200W laser is a good choice.

      Considering the comprehensive cleaning efficiency and cleaning effect, in order to achieve a high-efficiency and high-quality cleaning effect of the rust layer, it is recommended to use two lasers in combination: first, use a 1000W laser with a large spot and low power density to efficiently remove the shallow layer on the surface of the rail. Fe2O3 yellow rust layer; then use a small spot, high power density 200W laser to remove deeper black rust layer.