How to Solve the Problem of Aluminum Tube Rust?

Aluminum tube is a kind of non-ferrous metal tube, which refers to a metal tubular material formed by extrusion processing of pure aluminum or aluminum alloy. Aluminum tube is also called aluminum tube. Common aluminum tubes include aluminum round tubes, aluminum rectangular tubes and aluminum square tubes. Aluminum tubes have good corrosion resistance and are light in weight. Therefore, it is often used as a heat pipe. Although the aluminum pipe itself has good corrosion resistance, it still sometimes rusts. Why is there such a situation?

Why are aluminum pipes still rusting?

As metal surfaces come into contact with the environment, over time the surface metal is oxidized, losing the mechanical properties and appearance of its original metallic form. Aluminum is a material with strong corrosion resistance, but it will form alumina on the surface of aluminum under oxygen, and its corrosion resistance and gluten resistance will gradually disappear for a long time. Aluminum oxide is very thin, only a thousandth of a millimeter thick, but it is very hard and very wear-resistant. It is close to the surface of the aluminum material, so that the inner aluminum material cannot be exposed to the outside air, and prevents the aluminum material from continuing to rust. As a processed product of aluminum materials, aluminum tubes naturally have the same characteristics.

In addition, aluminum is very sensitive to acidic substances. When it encounters acid, it destroys the surface constituent layers of aluminum.

The solution to the corrosion of aluminum pipes

Now we all know that aluminum pipes have good corrosion resistance, but if there is rust on the surface of aluminum pipes, how can we solve this problem?

Pickling and Rust Removal

When using pickling to remove the rust of aluminum pipes, you must first remove the oil stains on the surface of the rusted aluminum pipes. If the oil stains are not removed, the rust will not be removed. However, this method has low rust removal efficiency and a long time. The pickling and rust removal operation is simple, the friction loss of the substrate is small, and the surface of the profile after rust removal is in a semi-bright state, which can be directly colored or surface oxidized.

Lye Descaling

Rusted aluminum is placed in an alkaline chemical solution. First of all, we must decide which alkaline solution to use according to the type of material and the surface condition of the aluminum material. Secondly, if there is grease on the aluminum surface, the grease must be cleaned first. If oil stains are not removed, the quality of the surface preparation may be compromised. The lye descaling is the same as the pickling descaling. It takes a long time to wait for the chemical reaction to occur, and the post-processing time is relatively long.

Oxidation Treatment of Aluminum Tube – Anodized Aluminum Tube

The best solution to the problem of aluminum pipe rusting is to anodize the aluminum pipe.

The principle of aluminum anodizing is essentially the principle of water electrolysis. When the current is passed, the following reactions will occur:

On the cathode, H2 is released according to the following reaction:

2H + + 2e → H2

On the anode:

4OH-4e → 2H2O + O2

The precipitated oxygen is not only molecular oxygen (O2) but also atomic oxygen (O) and ionic oxygen (O-2), which are usually represented by molecular oxygen in the reaction.

The aluminum as the anode is oxidized by the oxygen precipitated on it, forming an anhydrous Al2O3 film:

2Al + 3[O] = Al2O3 + 1675.7KJ

It should be pointed out that not all of the generated oxygen interacts with aluminum, and a part of it is precipitated in gaseous form.

Simply put, the use of anodizing process to solve the corrosion problem of aluminum tubes is: this method uses aluminum tubes or aluminum alloy tubes as anodes, puts them in the electrolyte for electrification treatment, and puts aluminum on the anodes to form the process. The aluminum oxide film formed by electrolysis is called anodic oxidation treatment of aluminum and aluminum alloy tubes.  

DC sulfuric acid anodizing is the most common application, because it has an anodizing treatment suitable for aluminum and most aluminum alloys; the film layer is thicker, harder, wear-resistant, and better corrosion resistance can be obtained after sealing; The film is colorless and transparent, with strong adsorption capacity, easy coloring, low processing voltage, low power consumption, and the processing process does not need to change the voltage cycle, which is conducive to continuous production and actual operation automation; sulfuric acid is less harmful to the human body than chromic acid, and is widely available. Advantages of low price.

Of course, there are also processed anodized aluminum tubes on the market now. Anodized aluminum tubing is more corrosion resistant than regular aluminum tubing. At the same time, it has higher hardness and better wear resistance. However, due to the different manufacturing methods of different manufacturers and the use of different aluminum materials, the quality of the anodized aluminum tubes produced is also uneven. Therefore, it is particularly important to choose a high-quality aluminum pipe supplier.

If you need high quality aluminum tube or anodized aluminum tube, you can contact us. We are a professional aluminum tube manufacturer, our products include but not limited to anodized aluminum tubes.

Price of aluminum tube

Usually the price will be affected by raw materials, market environment, research and development costs, etc. If you need to know the latest price of aluminum alloy, you can contact Staral’s customer service to answer your questions.

About Staral

Staral specializes in the deep processing business of aluminum products. Its main equipment include melting and holding furnaces from Switzerland GAUTSCHI, electro-magnetic stirring machines, refinery equipment and casting machines etc., 1+1+4 continuous hot rolling mill, 1+5 continuous hot rolling mill/three-stand and single-stand cold rolling mills with patent CVC flatness control imported from Germany SMS Group. Staral also placed large investments for high performance assisting equipment.

Staral’s main products are series 1, 2, 3, 4, 5, 6, 7, 8, etc. The main products are ultra wide aluminum alloy plate, aluminum alloy medium plate, aluminum alloy heckered plate, aluminum alloy brazing plate, aluminum coil, aluminum tube, aluminum profile, aluminum circle, aluminum forges, etc.

Staral has a large number of 5083/5052 aluminum alloy plates in stock, welcome to consult us and order.