Steel plates tend to rust over time, which not only affects their appearance but also impacts their price. Especially for laser processing, there are strict requirements for the plate surface. Any rust spots will prevent production, causing blade breakage and uneven plate surfaces that are prone to collide with the laser cutting head. So, how should we deal with rusted steel plates?

1. Manual rust removal

The original rust removal method was manual removal using tools such as shovels and hammers. Although these tools can be used during the process, the rust removal effect was not satisfactory. Unless it was done locally in a small area for emergency situations, this method would not be supported in other cases.

2. Electric tool rust removal

Electric tool rust removal refers to using compressed air or electrical power to drive rust removal tools to produce circular or reciprocating movements. When in contact with the steel plate surface, it utilizes the friction and impact force to remove rust and oxide scales. The rust removal efficiency and quality of electric tools are several orders of magnitude better than manual methods. This is also a common rust removal method in general coating projects.

In rainy, snowy, foggy or humid weather, the steel surface should be coated with primer to prevent re-rusting. If there is re-rusting before the primer coating, it should be removed again and the primer coating should be applied promptly.

3. Impact rust removal

Impact rust removal means that the steel plate uses the action of the abrasive material sucked in the center of the impeller and the abrasive material sprayed from the tip of the impeller to achieve high-speed impact, increasing the rust removal by friction.

4. Spray rust removal

Spray rust removal is to spray abrasive material at high speed onto the steel plate surface using compressed air. It utilizes the impact force and friction of the abrasive material to remove oxide scales, rust and dirt, giving the steel plate surface a certain roughness, which is conducive to enhancing the adhesion of the paint film.

5. Chemical rust removal

Chemical rust removal can also be called acid washing rust removal. The acid in the acid solution reacts with metal oxides, dissolving the metal oxides, thereby removing the oxide and rust from the steel surface.

There are two common acid washing methods: ordinary acid washing and comprehensive acid washing. After acid washing of the steel, it is prone to oxidation by air. Therefore, it must undergo passivation treatment to improve its rust prevention ability.

Passivation treatment refers to a method used on the steel plate after acid washing. It aims to prolong the re-rusting time, thereby forming a protective film on the steel surface, thereby improving its rust prevention performance.

Depending on the specific construction conditions, different treatment methods can be adopted. Generally, after acid washing of the steel plate, it should be rinsed with hot water until neutral, and then passivated. In addition, after acid washing of the steel, it can be washed with water immediately, then added 5% sodium carbonate solution for neutralization, and then washed with an alkaline solution, and then passivated.

6. Flame rust removal

Flame rust removal for steel plates refers to using a steel wire brush to remove the rust that adheres to the steel plate surface after the flame heating operation. Before rust removal of the steel plate surface, the thick rust layer attached to the steel plate surface should be removed first, and then rust removal is carried out by flame heating.