What Are The Difficulties in The Production Process of Zinc-aluminum-magnesium Steel Tubes?

As an important alloy material, zinc-aluminum-magnesium steel tubes are widely used in industrial production. There are indeed some difficulties in the production process. The following are some difficulties that may be encountered in the production process of zinc-aluminum-magnesium tubes:

1. It is difficult to control the alloy composition

Zinc-aluminum-magnesium alloy is a complex alloy, and the control of its composition plays a vital role in the performance of the product. However, during the production process, it is difficult to completely guarantee the uniformity and accuracy of the alloy composition. The quality of different raw materials varies, and the molar ratio of alloy components is difficult to strictly control. This leads to possible alloy component deviations and unevenness during the production process, which in turn affects the quality and performance of the product.

2. The extrusion process is difficult

Zinc-aluminum-magnesium tubes are mostly produced by extrusion, which is a relatively complex processing technology. During the extrusion process, parameters such as extrusion speed, temperature, and pressure need to be strictly controlled to ensure the shape and dimensional accuracy of the product. The extrusion process itself requires high mold accuracy. Once the mold is improperly designed or used for too long, it will lead to dimensional deviations and surface quality problems of the product.

3. Heat treatment is difficult

Zinc-aluminum-magnesium tubes usually require heat treatment during the production process to improve their mechanical properties and corrosion resistance. However, parameters such as heating temperature, holding time, and cooling rate need to be strictly controlled during the heat treatment process to avoid problems such as internal stress and uneven grain growth. The performance stability of heat treatment equipment also has a great impact on product quality and production efficiency.

4. Difficulty in surface treatment

Since zinc-aluminum-magnesium alloy has high anti-corrosion properties, products usually require surface treatment, such as spraying, oxidation, etc. However, different surface treatment processes have different requirements for products, and the adhesion and salt spray resistance of the coating also need to be considered. Moreover, the surface treatment process usually requires strict control of the operating environment and process parameters. Once errors occur, it can easily lead to product quality problems. When the steel strip is hot-dip plated and comes out of the zinc pot with the plating solution and is blown by an air knife, the magnesium on the surface of the coating is more easily oxidized. The surface of the coating will be covered by the magnesium oxide layer, which reduces the fluidity and reduces the fluidity. The fluidity of the bottom layer is different, and after cooling and solidification, transverse flow pattern defects will occur on the surface of the coating.

5. Processing issues in the furnace

Magnesium in the zinc-aluminum-magnesium plating bath is more easily oxidized than aluminum. Even in the protective gas of N2+H2 in the furnace, it may be oxidized by extremely trace amounts of oxygen and water vapor. Oxides are produced on the surface of the bath and may be adhered to the surface of the steel strip, causing defects. There is also the problem of zinc ash in the furnace. Since magnesium is very loosely oxidized, the zinc liquid on the surface of the plating bath in the furnace is exposed to the furnace gas and easily evaporates, producing zinc ash, which is more serious than ordinary galvanizing.

The difficulties in the production process of zinc-aluminum-magnesium steel tubes mainly focus on alloy composition, extrusion process, heat treatment, surface treatment, furnace treatment, etc. Only by strictly controlling key parameters during the production process, strengthening equipment maintenance and optimizing the process flow can we effectively solve these difficulties and improve product quality and production efficiency.